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Path: senator-bedfellow.mit.edu!enterpoop.mit.edu!gatech!howland.reston.ans.net!noc.near.net!uunet!news.claremont.edu!ucivax!news.service.uci.edu!nntpsrv From: iglesias@draco.acs.uci.edu (Mike Iglesias) Subject: Rec.Bicycles Frequently Asked Questions Posting Part 2/4 Nntp-Posting-Host: draco.acs.uci.edu Expires: 20 Jul 93 00:00:00 GMT Message-ID: <rec-bicycles-faq-2_930614@draco.acs.uci.edu> Newsgroups: rec.bicycles.misc,news.answers,rec.answers Approved: news-answers-request@MIT.Edu Organization: University of California, Irvine Lines: 1459 Supersedes: <rec-bicycles-faq-2_930418@draco.acs.uci.edu> References: <rec-bicycles-faq-1_930614@draco.acs.uci.edu> Date: 15 Jun 93 03:38:30 GMT Followup-To: rec.bicycles.misc Xref: senator-bedfellow.mit.edu rec.bicycles.misc:5555 news.answers:9403 rec.answers:1191 Archive-name: bicycles-faq/part2 [Note: The complete FAQ is available via anonymous ftp from draco.acs.uci.edu (128.200.34.12), in pub/rec.bicycles.] --------------------------------------------------------------------------- Bike Lockers (David H. Wolfskill david@dhw68k.cts.com) Many thanks to all who mailed or posted an interest in my quest for information regarding bike locker vendors; I apologize for the delay in posting this summary. My colleague -- thanks to some of that information -- was able to locate a sufficiently nearby vendor... one of the requirements of which I had not been aware was that the vendor must be fairly close (to Orange County, CA) -- to minimize shipping charges. (I apologize for failing to determine this issue before posting, and hope that some of the information about other vendors may be of value to others.) I figured it would be more useful for me to organize the information, so I have done so -- at the expense of making an attempt to give credit for the sources at the point the information is quoted. (I include a list of sources at the end of the article.) First, I received a few pointers to one Ellen Fletcher, such as: >For a comprehensive treatment of the bicycle parking subject, >along with a list of vendors & prices, contact Ellen Fletcher >at cdp!scvba@labrea.stanford.edu (put "ATTN ELLEN" in your >"To" line. [I requested clarification regarding addressing a note to Ms. Fletcher, but have yet to receive it.] >... Ellen Fletcher, 777-108 San Antonio Road, Palo Alto, CA >94303-4826, 415-495-8943. Fortunately, someone sent a list of products & manufacturers, apparently originally compiled by Ms. Fletcher. I have taken the liberty of using that list as a "base document" and have augmented it with other information I received; entries are alphabetically by munufacturer's name, since I don't always have product names: (Manufacturer, {Product Name(s)}, Address, Contact Person, Phone, FAX [comments]) American Bicycle Security Co., {BIKE SAFE}, PO Box 7359 Ventura, CA 93006, Thomas E. Volk, 805-933-3688 & 800-BIKESAF, 805-933-1865. Bike Lockers Company, {BikeLokr}, PO Box 445 W. Sacramento, CA 95691,, 916-372-6620, 916-372-3616 [approx. $300/locker, small quantities]. Bike-Lokr Mfg. Co., {?}, PO Box 123, Joplin, MO 64802, Jim Snyder, 417-673-1960/800-462-4049, 417-673-3642 [approx $450/locker, which holds 2 bikes; seem to be the lockers used by the Washington, DC Metro system] Bike Security Racks Co., {?}, PO Box 371, Cambridge, MA 02140,, 617-547-5755, - Bike Stable Co., Inc., {?}, PO 1402, South Bend, Indiana 46624,, 219-233-7060, - Cycle-Safe Inc., 2772-5 Woodlake Rd. SW Wyoming, MI 49509,, (616)538-0079 - David O'Keefe Company, {Super Secure Bike Stor}, P.O. Box 4457, Alamo, CA 94507, Thomas & David O'Keefe, 415-637-4440, 415-837-6234. General Machine company, {Bicycle Locker}, PO Box 405 Vacaville, CA 95696, Vitto Accardi, 707-446-2761, - J.G.Wilson Corp, {Park'n'Lock Bike Garage}, PO Box 599, Norfolk, VA 23501-0599, J.L.Bevan, 804-545-8341, 804-543-3249. Sunshine U-LOK Corp., {Secura Bike Locker}, 31316 Via Colinas Suite 102, Westlake Village, CA 91362, Doug Devine, 818-707-0110. [Specific information near the end of the article -- dhw.] Turtle Storage Ltd., {?}, P. O. Box 7359, Ventura, CA 93006,,, - [Ed. note: The complete posting is available in the archives on draco.acs.uci.edu.] --------------------------------------------------------------------------- Bike computer features [This table was created from information contained in Performance and Nashbar catalogs. In the table below, 'Y' means that the computer has the feature, 'O' means it is an optional feature.] Speed Ave Max Total Trip Elpsd Clock Auto Count Speed Speed Miles Miles Time OnOff Down Avocet 30 Y Y Y Y Y Y Avocet 40 Y Y Y Y Y Y Y Avocet 50 Y Y Y Y Y Y Y Cateye Micro Y Y Y Y Y Y Cateye Mity Y Y Y Y Y Y Y Cateye Mity 2 Y Y Y Y Y Y Y Y Cateye Wireless Y Y Y Y Y Y Y Cateye Vectra Y Y Y Y Y Y Cateye ATC Y Y Y Y Y Y Y Ciclo 37 Y Y Y Y Y Y Y Y Ciclo IIA Y Y Y Y Y Y Y Performance ITV Y Y Y Y Y Y Vetta Innovator Y Y Y Y Y Y Y Vetta HR1000 Y Y Y Y Y Y Y Y Vetta C-10 Y Y Y Y Y Y Y Vetta C-15 Y Y Y Y Y Y Y Vetta C-20 Y Y Y Y Y Y Y Vetta Two Y Y Y Y Y Y Y Vetta Wireless Y Y Y Y Y Y Y Y Specialized Y Y Y Y Y Y Y S Speed Zone Cadence Wireless Altitude Heart Rate Avocet 30 Avocet 40 Avocet 50 O Y Cateye Micro Y Cateye Mity Cateye Mity 2 Cateye Wireless Y Cateye Vectra Cateye ATC Ciclo 37 Ciclo IIA O O O Performance ITV Vetta Innovator Vetta HR1000 Y Vetta C-10 Vetta C-15 Vetta C-20 Y Vetta Two Y Vetta Wireless Y Specialized Speed Zone --------------------------------------------------------------------------- Recumbent Bike Info (David Wittenberg dkw@cs.brandeis.edu) (updated by Gary Walsh gary.walsh@canrem.com) Here's my standard response to questions about recumbents. I'd be happy to answer more specific questions. Here's some info I posted in the fall of 1990. I think it's still pretty much up to date. Changes from the last posting are in []'s. --David Wittenberg A few words about recumbent design, and then I'll provide a much larger list of recumbent manufacturers. There are three main choices in designing (or buying) a recumbent. Frame material -- all the ones I know of are either Alumninum or Steel. Wheelbase -- The front wheel can either be in front of the bottom bracket (long wheelbase) or behind it (short wheelbase). You can't have a medium wheelbase without a lot of extra work because the wheel and the bottom bracket would interfere with each other. Long wheelbase is reputed to be a bit more stable, while short wheelbase machines are often easier to fit into cars for transport. Some long wheelbase recumbents fold in neat ways to fit into a remarkably small space. Handlebars -- under seat or in front of the rider. Under seat is probably a more comfortable position when you get used to it (your hands just hang at your sides), and may be somewhat safer if you get thrown forward as there is nothing in front of you. High handlebars are somewhat faster as your arms are in front of you instead of at your side, thus reducing the frontal area. Some people find them more natural. [There are long wheelbase bikes with both high and low handlebars. I don't know of any short wheelbase, low handlebar recumbents, but there may be some I don't know of.] The following updated by Gary Walsh (gary.walsh@canrem.com) July 1992. There are a couple of interesting publications for recumbents: International Human Powered Vehicle Association P.O. Box 51255 Indianapolis, IN 46251 USA They publish Human Power Magazine and HPV News on all aspects of human powered transportation (bikes, aircraft, watercraft.) Dues are US$25/year in the U.S., Canada, and Mexico, and US$30 elsewhere. The Recumbent Bicycle Club of America/Recumbent Cyclist Magazine 17650-B6-140th Ave. SE, Suite 341 Renton, WA 98058 USA The best source of information on commercially available recumbents. Read the reviews in this magazine before you buy your first recumbent. Subscriptions are US$20/year Bulk or US$25/year First Class, in the U.S.A., and US$30/year elsewhere. Sample issue and info pack $5. See especially the buyers guide in issue #8 Oct-Dec 1992. Addresses of recumbent manufacturers: Ace Tool & Engineering (Infinity Recumbent) $1 for a flyer P.O Box 325 292 W. Harrison St. Mooresville, IN 46158 (317) 831-8798 Long wheelbase, low handlebars, aluminum frames. $499 + $85 for triple crank option. Information $1. Alternative Bikestyles P.O. Box 1344 Bonita, CA 91908 Phone (619)421-5118 Maverick $ Renegade LWB recumbents with upright handlebars. Framesets from $200. Complete bikes from $395. Advanced Transportation Products 550 3rd Ave. N. Edmonds, WA 98020 Phone (206)771-3719 R-20 SWB. $1350. Info pack $2. Angle Lake Cyclery 20840 Pacific Hwy S. Seattle WA 98198 Phone (206)878-7457 Counterpoint Presto SWB with upright handlebars. Presto SE Tour $1699. Presto SE High Performance $???. Presto CL $1399. Counterpoint Opus IV Tandem Opus CL $2999 Opus SE $3599 Tri Com Trikes $600-$700. Catalogue $2 Original Car-Cycle Technology 1311 Victoria Ave. Victoria, B.C., Canada V8S 4P4 Phone (604)598-7830 Fully fared commuter trike. Under development. DH Recumbents, Inc. 4007-G Bellaire Blvd. Houston, TX 77025 Phone (713)666-4452 LWB with upright steering. DH1000 $999, DH5000 $1395. Earth Traveller 1475 Lillian St. Livermore, CA 94550 Phone (415)449-8312 LWB trike with 2 wheels in back. Information $1. EcoCycle Earth Friendly Transportation 5755 NW Fair Oaks Dr. Corvallis, OR 97330 (503) 753-5178 The Trice is a recumbent tricycle, with two wheels in front. Touring $1495. Speed model $1595. Also imports Ross recumbent from England. $2 for flyer, $9 for video tape. Easy Racers, Inc Box 255H Freedom, CA 95019 (408) 722-9797 High handlebar, long wheelbase bikes. Easy Racer $2300. Frameset $1650. Gold Rush Replica, commercial version of the Dupont prize winning Gold Rush (world's fastest bike) also available. $2 for a catalog Lightning Cycle Dynamics 312 Ninth Street Lompoc, CA 93436 (805) 736-0700 P-38 Short Wheelbase, high handlebars. Full fairings are available, and very fast. $1750. F-40 fully fared version. Lightning Cycle Inc. (Tailwind) $1 for a brochure 3819 Rte. 295 Swanton, OH 43558 (419) 826-4056 Steel long wheelbase, underseat steering. Around $1200. Linear Manufacturing Inc. (Linear) Route 1, Box 173 Guttenberg, IA 52052 (319) 252-1637 Long Wheelbase aluminum bike with either high or low handlebars (You can convert from one to the other.) $900 to $1200. They sell through dealers, and if you get in touch with them they'll tell you where the nearest dealer is. Canadians see S.C. Safety Cycle below. Rans Recumbents 1104 E. Hwy. 40 Bypass Hays, KS 67601 (913) 625-6346 Rans Stratus A & B and Nimbus. LWB with upright handlebars. $995-$1495. ReBike P.O Box 725 Boca Raton, FL 33429 Phone (407)750-1304 The ReBike. A low priced semi-recumbent with upright steering. New and a big seller. $389. Rotator 915 Middle Rincon Rd. Santa Rosa, CA 95409 (707) 539-4203 Rotator Super-7 Streamliner - LWB with 20" wheels. Rotator Companion Tandem. Rhoades International 100 Rhoades Lane Hendersonville, TN 37075 Phone (615)822-2737 4-wheel pedal car. $999 and up. Information $4. Video $19. Ryan Recumbents, Inc. 3910 Stewart Rd., Unit F Eugene, Or 97402 (503)485-6674 Vanguard. Long wheelbase, underseat steering. From $1295. S.C. Safety Cycle Inc. 1340B St. Paul St. Kelowna, B.C. Canada V1Y 2E1 Canadian distributor of the Linear which is sold as "The Alternative." CAN$1495. Special Purpose Vehicles 120 Prospect Street Somerville, MA 02143 (617) 625-9030 Thebis International 110-2031 Malaview Ave. Sidney, B.C. Canada V8L 3X9 Phone (604)656-1237 1-800-667-6801 Thebis 201 Touring Trike. Two wheels in back. $2990. Trailmate 2359 Trailmate Dr. Sarasota FL 34243 Phone (813)755-5511 Fun Cycle and Bannana Peel trikes. $399. Turner Enterprises P.O.Box 36158 Los Angeles, CA 90036 Phone (383)-0030 SWB with underseat steering. Laid Back "E" frame kit $375. LB-2000 $1500. Frameset $899. Zzip Designs P.O. Box 14 Davenport, CA 95017 Phone (408)425-8650 Manufacturer of fairings for many of the bikes listed above. Cyclopedia P.O. Box 884 Adrian, MI 49221 1-800-678-1021 Good source for parts for builders. ---------------- European Recumbents Leitra APS PO Box 64 DK-2750 Ballerup, Denmark Leitra M2 fully fared commuter trike. 3400 DM for the trike. 5845 DM for complete vehicle with accessories. Bas Ten Brinke Postbus 10075 1301 Almere, Netherlands Flevo SWB front wheel drive. Fateba, Bachman & Co. Rosenstr. 9, 8400 Winterthur Switzerland Fateba Winglet L1 LWB. Kincycle Miles Kingsbury Lane End Road, Sands, High Wycombe, Bucks HP12 4JQ England The Kingcycle SWB. M5 Bram Moens Waalstraat 41, NL-4335 KL Middleburg, Netherlands. M5 SWB. Neatwork The Lees Stables Coldstream, Berwickshire, Scotland TD12-4NN Dealer for Kingcycle SWB and Radius Peer Gynt LWB. Radius-Spezialrader, Frie-Vendt-Str 16, D-4400 Munster, Germany RFA Peer Gynt LWB with underseat steering. More Recumbent Bike Info (Gary Walsh gary.walsh@canrem.com) [This has been copied from a flyer written by Robert Bryant of the Recumbent Cyclist Magazine. He has given me permission to submit it for the FAQ. - Gary] Have You Ever Considered a RECUMBENT BICYCLE? WHY RECUMBENT BICYCLES? There are many reasons to consider a recumbent. First and foremost is comfort. When you ride a recumbent bicycle you will no longer have an aching back, stiff neck, numb wrists or a sore a sore bottom. You will sit in a relaxed easy-chair position. You will be able to ride longer with less fatigue and arrive at your destination feeling refreshed. The recumbent position offerd you a great view of the countryside. While seated you will look straight ahead. This allows your lungs and chest more open and free breathing. Recumbents are very versatile machines. They can be used for a wide range of applications: recreational/sport riding, for the daily commute, a fast double century and they are great for long distance touring. RECUMBENT PERFORMANCE Recumbents hold all of the human-powered speed records. This is because they are aerodynamically superior to conventional bicycles; less frontal area means less wind resistance. The Lightning F-40 currently holds the Race Across America speed record of five days and one hour. Gardner Martin's Easy Racer Gold Rush, ridden by Fast Freddie Markham, was the winner of the Dupont Prize for breaking 65mph. You can currently buy production versions of these bicycles. Fairings for street use are common and optional equipment on most commercially built models. They protect you from rain, cold and wind, with up to a 30% reduction in drag. Commercially available recumbents are not always faster than conventional bicycles. It depends mainly on the individual rider. Your best bet is to do you homework and if your goal is performance and speed, be sure that you look for a recumbent designed for this purpose. COMMONLY ASKED QUESTIONS ABOUT RECUMBENT BICYCLES 1) Do recumbents climb hills well? Yes they do, although climbing on a recumbent requires a different technique, you must gear down and spin. Maintaining an efficient spin takes some practice & conditioning, once mastered, it takes less physical effort to climb hills. Depending on your riding style, your speeds can range from slowwer to even faster than on a conventional bicycle. 2) Can recumbents be seen in traffic? Recumbents with a higher seating position may be better suited for riding in traffic than some of the low-slung designs. The use of use of proper safety devices such as safety flags and reflective devices is recommended. Recumbent bicycles are different, futuristic and they get noticed. Many riders feel they get more respect from motorists while on their recumbents. 3) Are they safe? Recumbent's are safer than a conventional bicycle. Due to the low centre of gravity, they stop faster. Brakes can be evenly applied to both wheels simultaneously providing more traction without throwing the rider over the handlebars. In crash situations, the rider goes down to the side absorbing the impact with the hip and leg rather than flying over the handlebars and absorbing the impact on your head and shoulder. Straight ahead vision is also better on a recumbent, however, rear view mirrors are necessary for proper rearward vision. RECUMBENT PAST HISTORY Why are recumbents such a rare sight? Space age technology? New type of bicycle? Not really, recumbent bicycles actually go back as far as the mid to late 1800's with the Macmillan Velocopede and the Challand Recumbent. In the 1930's, a series of events took place that changed bicycling history. A French second category professional track cyclist named Francois Faure rode the Velocar, a two wheeled recumbent bicycle designed and built by Charles Mochet, to record-shattering speeds, breaking both the mile and kilometre records of the day. This created a storm of controversy within the U.C.I. (United Cycliste International), bicycle rating's governing body. The debate centred on whether the Velocar was a bicycle and were these records legal? In 1934 they ruled against the Mochet-Faure record, banning recumbent bicycles and aerodynamic devices from racing. Were U.C.I. members worried that the recumbent bicycle would displace the conventional design? Did they realize this would freeze bicycle and human-powered vehicle development for the next forty years? This is why bicycles of taday look very similar to the Starkey and Sutton Safety (upright/conventional) of 1885. Just think where bicycle technology would be today if the U.C.I. decision had gone the opposite way. MODERN RECUMBENT HISTORY Recumbent development was fairly quiet until the late 1960's. Dan Henry received some media attention for his long wheelbase design in 1968. In the early 1970's, the human-powered revolution was starting up on both the U.S. east coast by David Gordon, designer of the Avatar, and on the west coast by Chester Kyle. These pioneers recognized the need for further development of human-powered vehicles. In the late 1970's and early 1980's, this lead to the first commercial recumbent bicycle designs such as the Avatar, Easy Racer and Hypercycle. In 1990, the Recumbent Bicycle Club of America was founded by Dick Ryan who currently manufactures the Ryan Vanguard and was also involved with the Avatar project in the early 1980's. In 1988 recumbent promoter Robert Bryant got his start writing "Recumbent Ramblings," a column for "HPV News." In the summer of 1990, Robert founded the "Recumbent Cyclist Magazine," and in a short two years, RCM has become the source for recumbent bicyle information in the world today. SUBSCRIPTION INFORMATION RECUMBENT CYCLIST MAGAZINE 17560-B6-140th Ave SE, Ste 341 Renton WA 98058 __$2 Info-Pak/recumbent manufacturer list __$5 Current sample issue with info-pak/list __$20 USA Bulk Mail Subscription __$25 USA First Class Mail Subscription Rush Service __$30 Canada Air Mail __$35 Worldwide Air Mail (USA funds) (anywhere outside USA/CAN) __$50 Junior Supporter (includes 3 copies of each issue, mailed first class __$100 RBCA Supporter (includes 10 copies of each issue mailed Priority) BACK ISSUE ORDERING INFO -Back issues are mailed 3rd class postage. (allow 4 weeks for delivery.) -First Class Mail/Rush Service - add $.50 per issue. -Canadian Air Mail/Rush Service - add $1.00 per issue. -Worldwide Air Mail - add $2.00 per issue. -Super-Rush Service? We can do FEDEX overnight C.O.D. $4.00 __RC#2 Flevo & CSPC "Poor Man's Composite" $4.00 __RC#3 DH5000 LWB Road Test $4.00 __RC#4 Ryan Vanguard Road Test/F-40/Flevo $4.00 __RC#5 Linear LWB Road Test/Omega HPV/HPV Design Info $4.50 __RC#6 Easy Racer Road Test $4.50 __RC#7 Lightning P-38 Road Test $4.50 __RC#8 1992 Recumbent Buyers Guide $4.50 __RC#9 A.T.P. R-20 SWB Road Test $4.50 __RC#10 Thebis Trike Road Test $4.50 __RC#11 Counterpoint Presto Road Test $4.50 __RC#12 Rans Road Test (available 9/92) $4.50 __RC#13 Trice Road Test (Available 11/92) $4.50 __RC#14 (Available 1/93) $4.50 __RC#14 (Available 3/93) $4.50 __RC#15 (Available 5/93) --------------------------------------------------------------------------- Buying a Bike One thing to decide before buying a bike is what type to buy. Here's a brief list: Road bike Once known as a "ten-speed", most are now 12 or 14 (or even 16) speed. There are several sub-types: racing, sport, and touring, the difference mostly in frame geometry. ATB All-terrain bike, also known as mountain bike. Great for riding in the dirt, these bikes usually have fat, knobby tires for traction in dirt and gravel. Hybrid A bike that borrows from road bikes and ATBs. For example, they have the light frame and 700c wheels of road bikes and fat knobby tires, triple cranks, wide-range derailleurs, flat handlebars and cantilever brakes from mountain bikes. Bike buying hints When you're ready to buy a bike, you should first decide what you want to use the bike for. Do you want to race? Do you want to pedal along leisurely? Do you want to ride in the dirt? Next, you should decide on a price range. Plan to spend at least $350 for a decent quality bike. Now find a good bike shop. Ask friends who bike. Ask us here on the net. Chances are, someone here lives in your area and can recommend a shop. Now that you are ready to look for a bike, visit the shop(s) you have selected. Test ride several bikes in your price range. How does it feel? Does it fit you? How does it shift? Does it have the features you are looking for? How do the shop personnel treat you? Remember that the shop gets the bike disassembled and has to spend a couple of hours putting it together and adjusting things, so look for sloppy work (If you see some, you may want to try another shop). You might want to try a bike above your price range to see what the differences are (ask the salesperson). Ask lots of questions - pick the salesperson's brain. If you don't ask questions, they may recommend a bike that's not quite right for you. Ask about places to ride, clubs, how to take care of your bike, warranties, etc. Good shops will have knowledgable people who can answer your questions. Some shops have free or low-cost classes on bike maintenance; go and learn about how to fix a flat, adjust the brakes and derailleurs, overhaul your bike, etc. Ask your questions here - there are lots of people here just waiting for an excuse to post! Make sure that the bike fits you. If you don't, you may find that you'll be sore in places you never knew could be so sore. For road bikes, you should be able to straddle the top tube with your feet flat on the ground and still have about 1 inch of clearance. For mountain bikes, give yourself at least 2-3 inches of clearance. You may need a longer or shorter stem or cranks depending on your build - most bikes are setup for "average" bodies. The bike shop can help you with adjustments to the handlebars and seat. Now that you've decided on a bike, you need some accessories. You should consider buying a helmet a frame pump a tube repair kit tire levers (plastic) a pressure gauge a seat pack (for repair kit, wallet, keys, etc) gloves a water bottle and cage a lock The shop can help you select these items and install them on your bike. =========================================================================== Tech =========================================================================== Technical Support Numbers (Joshua Putnam Joshua_Putnam@happy-man.com) [This list is now in the ftp archives as it is too long to put here] --------------------------------------------------------------------------- Ball Bearing Grades (Bill Codding peda@simplicity.Stanford.EDU) (Harry Phinney harry@hpcvlx.cv.hp.com) Following is a description of the different grades of ball bearings. The grade specifies the sphericity of the balls in millionths of an inch. Thus, grade 25 are round to 25/10^6, while grade 1000 are good to 1/1000 (i.e. not all that round, but probably good enough for our uses). Grade 25: the highest quality normally available, aka "Campagnolo quality": hardened all the way through, best alloys, coatings, roundness, and durability. Evidently, a recent bottom-bracket overhaul article in "Bicycling Plus Mountain Bike" magazine recommended these. Campy's tech reps claim that the bearings in a set (usually in a little paper bag) are matched. One should not mix bearings from different sets. Grade 200: mid-range Grade 1000: seems to be the lowest, may only be surface hardened. Good sources for ball bearings: Your local bike shop (make sure you're getting the grade you want) Bike Parts Pacific Bike Nashbar 1-800-NASHBAR ($1-$3 per 100 Grade 25) The Third Hand 1-916-926-2600 ($4-$7 per 100 Grade 25) --------------------------------------------------------------------------- SIS Cable Info (Jobst Brandt jobst_brandt%40@hp1900.desk.hp.com) After Joe Gorin described the SIS "non-compressive" cable housing to me I got myself a sample to understand what the difference is. I believe "non-compressive" is a misnomer. This cable housing is NOT non-compressive but rather a constant length housing. As far as I can determine, and from reports from bike shops, this housing should not be used for brakes because it is relatively weak in compression, the principal stress for brake housing. SIS housing is made of 18 strands of 0.5mm diameter round spring steel wire wrapped in a 100mm period helix around a 2.5mm plastic tube. The assembly is held together by a 5mm OD plastic housing to make a relatively stiff cable housing. Because the structural wires lie in a helix, the housing length remains constant when bent in a curve. Each strand of the housing lies both on the inside and outside of the curve so on the average the wire path length remains constant, as does the housing centerline where the control cable resides. Hence, no length change. A brake cable housing, in contrast, changes length with curvature because only the inside of the curve remains at constant length while the outside (and centerline) expands. Shimano recommends this cable only for shift control but makes no special effort to warn against the danger of its use for brakes. It should not be used for anything other than shift cables because SIS housing cannot safely withstand compression. Its wires stand on end and have no compressive strength without the stiff plastic housing that holds them together. They aren't even curved wires, so they splay out when the outer shield is removed. Under continuous high load of braking, the plastic outer housing can burst leaving no support. Besides, in its current design it is only half as flexible as brake cable because its outer shell is made of structurally stiff plastic unlike the brake cable housing that uses a soft vinyl coating. Because brake cables transmit force rather than position, SIS cable, even if safe, would have no benefit. In contrast, with handlebar controls to give precise shift positioning, SIS housing can offer some advantage since the cable must move though steering angles. SIS housing has no benefit for downtube attached shifters because the cable bends do not change. --------------------------------------------------------------------------- Milk Jug Mud Flaps (Chuck Tryon bilbo@bisco.kodak.com) Actually, I have used plastic like this (or in my case, some red plastic from a cheap note book cover -- it's heavier) to extend the bottom (rear) end of the front fender. The Zephals are good, but they don't stop the splash from where the tire hits the road from getting on my feet. What I did was cut a small triangle about 3in (~7cm) wide by 6in (~15cm) long, cut a hole in the top of it and the bottom end of the fender, and use a pop-rivet (with washers to prevent tear out) to attach it. On a road bike, it should be end up being within a few inches of the road. ATB's will need more clearance, so this won't work well off road. | | | | /| o |\ <----- rivet with washer on inside | \___/ | / \ <---- flap fits inside of the fender, and follows the | | curve, which gives it some stiffness. | | | | \_________/ | | | | <----- bottom of tire \_/ --------------------------------------------------------------------------- Lubricating Chains Lubricating chains is a somewhat religious issue. Some advocate oil, some Teflon-base lubricants, some paraffin wax. The net majority favors a lubricant that does not leave an oily coating on the chain that can attract dirt, which will hasten chain/chainring/freewheel sprocket wear. If you want to use paraffin wax, make sure you melt the wax in a double boiler! Failure to do so can lead to a fire. You can use a coffee can in a pan of boiling water if you don't want to mess up good cookware. After the wax has melted, put the chain in the wax and simmer for 10 minutes or so. Remove the chain, hang it up, and wipe the excess wax off. Let it cool and reinstall on your bike. When using a liquid lubricant, you want to get the lube onto the pins inside the rollers on the chains, not on the outside where it does little good. Oilers with the narrow tubes are good for this because you can put the lube where you want it. Work the oil into the chain after applying it, wipe the chain off, and reinstall on your bike. --------------------------------------------------------------------------- Wear and Gear Slippage (Jobst Brandt jobst_brandt@hplabs.hp.com) There seems to be a lot of speculation on what makes chains wear and how to lubricate a chain. There are a number of ways to take care of a chain. Of these, some traditional methods are the most damaging to chain life and others work to prolong life. As was mentioned on the net, chains don't stretch in the sense that the metal elongates, but the parts wear. Wear in the pins and sleeves change the length of the chain as the pins fit more loosely. The wear arises primarily from road grit that enters the chain when it is oiled. Grit on the outside of a chain is the ugly black stuff that gets on your leg. This dirt has no effect on chain function because it can't get inside to do damage. Only when a dirty chain is oiled does this grit get to the place where it can cause damage. Note that commercial abrasive grinding paste is made of oil and silicon dioxide (sand) and silicon carbide (sand). You couldn't do a better job if you tried to destroy a chain than to oil a road dirt (previously oiled) encrusted chain. Primitive rule #1: Never oil a chain on the bike. This means you should clean the grit off the chain before oiling it. Because this is essentially impossible without submerging the chain in a solvent bath (kerosene or commercial solvent), you must take the chain off the bike. The fine grit can only be removed from the interior of the chain in liquid suspension. A good example of this can be seen by using a Vetta (on the bike) chain cleaner and subsequently cleaning the same chain in a solvent bath. The best grit remains until last and there's plenty of it. Of course it isn't always possible to remove a chain and there are times (in the rain) when a chain screams for oil when a good cleaning is not an option. Removing the solvent from the chain after the rinse is important. Compressed air is not readily available in the household nor is a centrifuge. You can go outdoors and sling the chain around. This works best if the chain is a closed loop. You don't have to press the pin completely in for this. The other way is to evaporate it. You should probably avoid accelerated drying methods because they could be explosive. The hot gear lube method works but it also acts as efficient fly paper, collecting plenty of grime between cogs. Motor oil is good but motorcycle chain lubricants are better because they have volatile solvents that allow good penetration for their relatively viscous lubricant. Paraffin works poorly because it is not mobile and cannot replenish the bearing surface once it has been displaced. Sedisport The Sedisport chain, although the strongest and one of the lightest chains, achieves its light weight at the expense of durability. This chain has no sleeve that on most roller chains supports the roller on its outside and furnishes the bearing for the pin on the inside. Normally the inside of the sleeve is well protected against lubricant depletion because both ends are covered by closely fitting side plates. In the Sedisport there is no sleeve and the formed side plates support the roller and pin with a substantial central gap. In the wet, lubricant is quickly washed out of pin and roller and the inferior bearing for the pin and roller often gall and bind. In good weather this may not be a problem. Because this chain has feet of clay in the wet, Sedis re-introduced their earlier 5 element conventional chain, calling it a "chain for all seasons". The lightweight Regina chain goes one step farther and omits the pin, leaving the side plates to hinge directly on the sleeve. This gives them a knife edge bearing area that galls at the slightest lube depletion. Chain Life This is almost entirely a cleanliness and lubrication question rather than a load problem. The effect of load variations is insignificant when compared to the lube and grit effects for bicycles. The primary chains on motorcycles are operated under clean conditions and last years while the exposed rear chains must be replaced often. The only way to test whether a chain is worn is by measurement. The chain has a half inch pitch and, when new, has a pin at exactly every half inch. As the pins and sleeves wear this spacing increases and becomes damaging to sprockets. When the chain pitch grows over one half percent it is time for a new chain. At one percent chainring damage progresses rapidly. By holding a ruler along the chain on your bike, align an inch mark with a pin and see how far off the mark the pin is at twelve inches. An eighth of an inch (0.125) is the ten percent limit while more than a sixteenth is a prudent time to get a new chain. Skipping Chain When you put on a new chain, its pitch is exactly one half inch. A sprocket, worn by a longer pitch (worn) chain, has hooked teeth. The hooked profile is formed by the rollers of a worn chain as they exit the sprocket under load. Rollers of a new chain with correct pitch exit under no load because the load is transferred to the next roller before disengagement. However, with hooked sprockets the new chain cannot engage under load because the pitch is too small to get over the hook and into the pocket. These differences are only a few thousandths of an inch but that is enough to prevent engagement when the previous roller is fully engaged. As a chain wears it concentrates more of its load on the last tooth of a sprocket before disengagement because its pitch no longer matches the pitch of the sprocket. This effect sometimes breaks off sprocket teeth. The load concentration on the sprocket also accelerates wear and is another reason to replace a chain at 1/16th inch wear. --------------------------------------------------------------------------- Adjusting Chain Length (Bob Fishell spike@cbnewsd.att.com) For all Shimano SIS and Hyperglide systems, the chain is sized by shifting to the smallest rear cog and the largest front sprocket, then sizing the chain so that the derailleur pulleys are on a vertical line, or as close as you can get to it. Note that this will result in the same chain length for any freewheel within the capacity of the derailleur, so it usually is not necessary to re-size the chain for a different cogset with these systems. The other rule I've used (friction systems) involves shifting to the largest chainring and the largest rear cog, then sizing the chain so that the pulleys are at a 45 degree angle to the ground. The rules probably vary from derailleur to derailleur. In general, you may use the capacity of the rear derailleur cage as a guideline. You want the chain short enough so the cage can take up the slack in the smallest combination of chainwheel and rear cog you will use. The chain must also be long enough so that the cage still has some travel in the largest combination you will use. For example, if you have a 42x52 crank and a 13x21 freewheel, the smallest combination you would use would be a 42/14 (assuming you don't use the diagonal). If the cage can take up the slack in this combo, it's short enough. If the cage has spring left when you are in the 52/19 combo (again, you are not using the diagonal), it's long enough. --------------------------------------------------------------------------- Hyperglide chains (Mark Chandler chandler@wc.novell.com) For those of you that are tired of dealing with Shimano's chains with the special pins, I've found that the following chains work well with Shimano Hyperglide gearing systems: DID SuperShift Sedis ATB Union 800 Union 915 The SuperShift is probably the best performer of the bunch, followed by the ATB and 915. The 800 doesn't do too well with narrow cogsets (i.e., 8-speeds) because the raised elliptical bumps on the side-plates tend to rub on the adjacent cogs. I've also found that these chains work well on SunTour systems. The 915, however, works better on PowerFlo cogs than it does on regular (AccuShift) cogs (where it tends to slip when shifting). --------------------------------------------------------------------------- Cranks and Bottom Brackets Bottom Bracket Info (Jobst Brandt jobst_brandt@hplabs.hp.com) The four kinds of BB threads in common use today are Italian, British, French, and Swiss, possibly in that order of occurrence. Diameter Pitch Right Left Cup -------- ----- ----- ----- Italian 36mm x 24F tpi right right tpi (threads per inch) British 1.370" x 24F tpi left right French 35mm x 1mm right right Swiss 35mm x 1mm left right Unless there is something wrong with the right hand cup it should not be removed but should be wiped clean and greased from the left side. The thread type is usually marked on the face of both left and right cups. Swiss threads are rare but if you have one it is good to know before attempting removal. --------------------------------------------------------------------------- Crank noises (Phil Etheridge phil@massey.ac.nz) I've had the creaky crank problem on every bike I've owned which has had cotterless cranks. Until now, I've never known a good solution to the problem. One suggestion I had was to replace the crank, but that wasn't something I was prepared to do on 1 month old bike under warranty. The shop mechanic spent half an hour with me and my bike sorting it out. Tightening the crank bolts and pedal spindle (i.e. onto the crank) didn't help (as Jobst will tell you). Removing each crank, smearing the spindle with grease and replacing the crank eliminated most of the noise. Removing each pedal, smearing grease on the thread and replacing it got rid of the rest of the noise. Greasing the pedal threads is a new one on me, but it makes a lot of sense, since they are steel and the crank aluminum. I thought it was worth relating this story, as creaky cranks seems to be quite a common problem. --------------------------------------------------------------------------- Cracking/Breaking Cranks (Jobst Brandt jobst_brandt@hplabs.hp.com) [Ed note: Yes, another disputed issue is contained here - whether to lube the crank tapers before installing the crankarms. This has popped up from time to time on rec.bicycles, and has never been resolved one way or the other. The text here is Jobst's viewpoint.] Cranks break because they are aluminum and because they have high stress at various points. The worst of these points are at the pedal eye and where the spider fingers join the right crank. The pedal eye is a bad place because the joint is incorrectly designed, but since it is a standard, it may not be changed since it seems to work. This joint always moves and causes fretting corrosion and cracks. These cracks propagate into the crank and cause failure. A better joint here would be a 45 degree taper instead of a flat shoulder at the end of the pedal thread. The thin web between the spider and crank, another common crack origin on cranks like the Campagnolo Record, was nicely redesigned in the C-Record crank, but to make up for that the C-Record is otherwise weaker than the Record version. My experience is that they break in about 1500 miles because the pedal eye has a smaller cross section than the Record model, but maybe the alloy is poorer too. I have subsequently used Dura Ace cranks for more than two years with no failure yet. I don't believe in eternal life here either. Aluminum has no safe fatigue limit but just gets progressively safer as stress is reduced. In contrast, steel has a threshold below which failures cease. Therein lies some of the problem. As for cranks loosening, one can view the junction between spindle and crank in an exaggerated elastic model where the spindle is made of plastic and the crank of Rubbermaid household rubber. The crank, once properly installed and the retaining bolt in place, squirms on the square taper when under torque. During these deformations the crank can move only in one direction because the bolt prevents it from coming off. The crank always slides farther up the taper. Proof that the crank squirms is given by the fretting rouge always found on the spindle, whether lubricated or not, when a crank is pulled off after substantial use. As was mentioned by various observers, the left crank bolt is usually looser, after use, than the right one and this could be anticipated because the two cranks differ in their loading. This does not mean the left crank is looser. Actually it is tighter, only the bolt is looser. The left crank is more heavily loaded because it experiences offset twist from the pedal at the same time it transmits torque to the spindle. The right crank, being connected to the chain, experiences either spindle torque from the left pedal or twist from the right pedal but not torque and twist at the same time. In this squirming mode, cranks wander away from the retaining bolt and leave it loose after the first hard workout (for riders of more than 150 lbs). The bolts should NOT be re-tightened because they were correctly tight when installed. Cranks have been split in half from repeated follow-up tightening, especially left cranks. The spindle should be lubricated before installing cranks. A wipe of a mechanic's finger is adequate since this is to prevent galling in the interface. To prevent losing a loose crank bolt, the "dust" cover that is in fact the lock cap should be installed. Those who have had a crank spindle break, can attest to the greater stress on the left side because this is the end that always breaks from fatigue. A fatigue crack generally has a crystalline appearance and usually takes enough time to develop that the face of the fracture oxidizes so that only the final break is clean when inspected. Because a notch acts to concentrate stress, the advancing crack amplifies this effect and accelerates the advance once the crack has initiated. I have heard of instructions to not lubricate spindles before installing cranks but I have never been able to find it in any manufacturer's printed material. Although I have broken many Campagnolo cranks, none has ever failed at the spindle. I am certain that the standard machine practice of lubricating a taper fit has no ill effects. I have also never had a crank come loose nor have I re-tightened one once installed. --------------------------------------------------------------------------- Biopace chainrings Biopace chainrings have fallen into disfavor in recent years. They are hard to "pedal in circles". The early Biopace chainrings were designed for cadences of around 50-70 rpm, while most recommend a cadence of 80-100 rpm. Newer Biopace chainrings are less elliptical, but the general consensus is to (if you are buying a new bike) get the dealer to change the chainrings to round ones. --------------------------------------------------------------------------- Snakebite flats Snakebite flats are usually caused by the tire and tube being pinched between the road and the rim, causing two small holes in the tube that look like a snakebite. The usual causes are underinflation, too narrow a tire for your weight, or hitting something (rock, pothole) while having your full weight on the tire. The obvious solutions are to make sure your tires are inflated properly, use a larger size tire if you weigh a lot, and either avoid rocks and potholes or stand up with your knees and elbows flexed (to act like shock absorbers) when you go over them. --------------------------------------------------------------------------- Blown Tubes (Tom Reingold tr@samadams.princeton.edu) Charles E Newman writes: $ Something really weird happened at 12:11 AM. My bike blew a $ tire while just sitting parked in my room. I was awakened by a noise $ that scared the livin ^&$% out of me. I ran in and found that all the $ air was rushing out of my tire. How could something like happen in the $ middle of the night when the bike isn't even being ridden? I have $ heard of it happening when the bike is being ridden but not when it is $ parked. This happened because a bit of your inner tube was pinched between your tire bead and your rim. Sometimes it takes a while for the inner tube to creap out from under the tire. Once it does that, it has nothing to keep the air pressure in, so it blows out. Yes, it's scary. I've had it happen in the room where I was sleeping. To prevent this, inflate the tire to about 20 psi and move the tire left and right, making sure no part of the inner tube is pinched. --------------------------------------------------------------------------- Mounting Tires (Douglas Gurr dgurr@daimi.aau.dk) A request comes in for tyre mounting tricks. I suspect that this ought to be part of the FAQ list. However in lieu of this, I offer the way it was taught to me. Apologies to those for whom this is old hat, and also for the paucity of my verbal explanations. Pictures would help but, as always, the best bet is to find someone to show you. First of all, the easy bit: 1) Remove the outer tyre bead from the rim. Leave the inner bead. Handy hint. If after placing the first tyre lever you are unable to fit another in because the tension in the bead is too great then relax the first, slip the second in and use both together. 2) Pull out the tube finishing at the valve. 3) Inspect the tube, find the puncture and repair it. Now an important bit: 4) Check tyre for thorns, bits of glass etc - especially at the point where the hole in the tube was found. and now a clever bit: 5) Inflate the tube a _minimal_ amount, i.e. just sufficient for it to hold its shape. Too much inflation and it won't fit inside the tyre. Too little (including none at all) and you are likely to pinch it. More important bits: 6) Fit the tube back inside the tyre. Many people like to cover the tube in copious quantities of talcum powder first. This helps to lubricate the tyre/tube interface as is of particular importance in high pressure tyres. 7) Seat the tyre and tube over the centre of the rim. 8) Begin replacing the outer bead by hand. Start about 90 degrees away from the valve and work towards it. After you have safely passed the valve, shove it into the tyre (away from the rim) to ensure that you have not trapped the tube around the valve beneath the tyre wall. Finally the _really_ clever bit: 9) When you reach the point at which you can no longer proceed by hand, slightly _deflate_ the tube and try again. Repeat this process until either the tyre is completely on (in which case congratulations) or the tube is completely deflated. In the latter case, you will have to resort to using tyre levers and your mileage may vary. Take care. and the last important check: 10) Go round the entire wheel, pinching the tyre in with your fingers to check that there is no tube trapped beneath the rim. If you have trapped the tube, deduct ten marks and go back to step one. Otherwise .... 11) Replace wheel and reinflate. --------------------------------------------------------------------------- More Flats on Rear Tires (Jobst Brandt jobst_brandt@hplabs.hp.com) Most sharp obstacles except tetrahedral glass slivers and puncture vine gets stuck more often is that the front tire upsets the sharp object just in time for the rear tire to catch it head-on. This front to rear effect is also true for motor vehicles. Nails lying on the road seldom enter front tires. When dropped on the road by a moving vehicle, the nail slides down the road aligning itself pointing toward traffic because it tends to roll around until it is head first. The tire rolls over it and tilts it up so that if the speed is ideal, the rear tire catches it upright. I once got a flat from a one inch diameter steel washer that the rear tire struck on edge after the front tire flipped it up. When it is wet glass can stick to the tire even in the flat orientation and thereby get a second chance when it comes around again. To add to this feature, glass cuts far more easily when wet as those who have cut rubber tubing in chemistry class may remember. A wet razor blade cuts latex rubber tubing in a single slice while a dry blade only makes a nick. --------------------------------------------------------------------------- What holds the rim off the ground? (Jobst Brandt jobst_brandt@hplabs.hp.com) > What forces keep the rim of a wheel with pneumatic tires off the > ground. It obviously can't be the air pressure because that's acting > from top as well as from below. As has been pointed out, the casing walls pull on the rim (or its equivalent) and thereby support the load. The casing leaves the rim at about a 45 degree angle, and being essentially a circular cross section, it is in contact with the rim over its inner quarter circle. At least this is a good representative model. The visualization may be simpler if a tubular tire is considered. It makes no difference whether the tire is held on by glue or is otherwise attaches to the rim such as a clincher is. Either way the tire is attached to the rim, a relatively rigid structure. Under load, in the ground contact zone, the tire bulges so that two effects reduce the downward pull (increase the net upward force) of the casing. First, the most obvious one is that the casing pulls more to the sides than downward (than it did in its unloaded condition); the second is that the side wall tension is reduced. The reduction arises from the relationship that unit casing tension is equivalent to inflation pressure times the radius of curvature divided by pi. As the curvature reduces when the tire bulges out, the casing tension decreases correspondingly. The inflated tire supports the rim primarily by these two effects. Tire pressure changes imperceptibly when the tire is loaded because the volume does not change appreciably. Besides, the volume change is insignificant in small in comparison to the volume change the air has undergone when being compressed into the tire. In that respect, it takes several strokes of a frame pump to increase the pressure of a tire from 100 psi to 101. The air has a low spring constant that acts like a long soft spring that has been preloaded over a long stroke. Small deflections do not change its force materially. For convenience car and truck tires are regularly inflated to their proper pressure before being mounted on the vehicle. --------------------------------------------------------------------------- Anodized vs. Non-anodized Rims (Jobst Brandt jobst_brandt@hplabs.hp.com) There are several kinds of dark coatings sold on rims. Each suggests that added strength is achieved by this surface treatment while in fact no useful effects other than aesthetic results are achieved. The colored rims just cost more as do the cosmetically anodized ones. The hard anodized rims do not get stronger even though they have a hard crust. The anodized crust is brittle and porous and crazes around spoke holes when the sockets are riveted into the rim. These cracks grow and ultimately cause break-outs if the wheel is subjected to moderate loads over time. There is substantial data on this and shops like Wheelsmith, that build many wheels, can tell you that for instance, no MA-2 rims have cracked while MA-40 rims fail often. These are otherwise identical rims. Hard anodizing is also a thermal and electrical insulator. Because heat is generated in the brake pads and not the rim, braking energy must cross the interface to be dissipated in the rim. Anodizing, although relatively thin, impedes this heat transfer and reduces braking efficiency by overheating the brake pad surfaces. Fortunately, in wet weather, road grit wears off the sidewall anodizing and leaves a messy looking rim with better braking. Anodizing has nothing to do with heat treatment and does not strengthen rims. To make up for that, it costs more. --------------------------------------------------------------------------- Reusing Spokes (Jobst Brandt jobst_brandt@hplabs.hp.com) >I just bent my wheel and am probably going to need a new one >built. Can I reuse my old, 3 months, spokes in the new wheel. >The guy at the shop gave me some mumbo jumbo about tensioning or >something. There is no reason why you should not reuse the spokes of your relatively new wheel. The reason a bike shop would not choose to do this is that they do not know the history of your spokes and do not want to risk their work on unknown materials. If you are satisfied that the spokes are good quality you should definitely use them for you new wheel. The spokes should, however, not be removed from the hub because they have all taken a set peculiar to their location, be that inside or outside spokes. The elbows of outside spokes, for instance, have an acute angle while the inside spokes are obtuse. There are a few restrictions to this method, such as that new rim must have the same effective diameter as the old, or the spokes will be the wrong length. The rim should also be the same "handedness" so that the rim holes are offset in the correct direction. This is not a fatal problem because you can advance the rim one hole so that there is a match. The only problem is that the stem will not fall between parallel spokes as it should for pumping convenience. Take a cotton swab and dab a little oil in each spoke socket of the new rim before you begin. Hold the rims side by side so that the stem holes are aligned and note whether the rim holes are staggered in the same way. If not line the rim up so they are. Then unscrew one spoke at a time, put a wipe of oil on the threads and engage it in the new rim. When they are all in the new rim you proceed as you would truing any wheel. Details of this are in a good book on building wheels. The reason you can reuse spokes is that their failure mode is fatigue. There is no other way of causing a fatigue failure than to ride many thousand miles (if your wheel is properly built). A crash does not induce fatigue nor does it even raise tension in spokes unless you get a pedal between them. Unless a spoke has a kink that cannot be straightened by hand, they can all be reused. --------------------------------------------------------------------------- Clinchers vs. Tubulars (F.J. Brown F.Brown@massey.ac.nz) D.H.Davis@gdt.bath.ac.uk gave some useful hints on mounting clinchers, mostly involving the use of copious quantities of baby powder, and trying to convince me that clinchers aren't difficult to mount, so ease of mounting isn't a valid reason for preferring tubulars. wernerj@lafcol.lafayette.edu wrote that although average tubulars ride 'nicer' than average clinchers, there are some clinchers around that ride just as 'nice'. He also said that ease of change isn't a good reason for preferring tubulars as if you flat in a race, you're either going to swap a wheel or drop out. He pointed out that tubulars end up costing $20 - $80 per flat. ershc@cunyvm.cuny.edu gave some of the historic reasons that tubulars were preferred: higher pressures, lower weight, stronger, lighter rims. Said that only a few of these still hold true (rim strength/weight, total weight), but he still prefers the 'feel' of tubulars. leka@uhifa.ifa.hawaii.edu started this thread with his observations on clinchers seperated from their rims in the aftermath of a race crash. stek@alcvax.pfc.mit.edu comments on improperly-glued tubulars posing a threat to other racers by rolling off, and noted that this couldn't happen with clinchers. jobst_brandt@hplabs.hp.com agreed with stek, with the additional note that it is inadequate inflation that often allows tubulars to roll. Kevin at Buffalo agreed with stek and jobst about tubulars (improperly or freshly glued) sometimes rolling. ruhtra@turing.toronto.edu says he uses clinchers for cost and convenience. Clinchers let him carry around a tiny patch kit and some tyre irons, costing 60c, whereas tubulars would require him to carry a whole tyre, and would cost more. CONCLUSIONS: THE CLINCHER VS. TUBULAR WAR Tubulars - used to be capable of taking higher pressures, had lower weight and mounted onto stronger, lighter rims than clinchers. Clinchers have now largely caught up, but many cyclists thinking hasn't. Tubular tyre + rim combination still lighter and stronger. - are easier to change than clinchers. This matters more to some people than others - triathletes, mechanical morons and those riding in unsupported races. - cost megabucks if you replace them every time you puncture. ***However*** (and none of the North Americans mentioned this) down here in Kiwiland, we ***always*** repair our punctured tubulars (unless the casing is cut to ribbons). The process doesn't take much imagination, you just unstitch the case, repair the tube in the normal manner using the thinnest patches you can buy, stitch it back up again and (the secret to success) put a drop of Superglue over the hole in the tread. - can roll off if improperly glued or inflated. In this case, you probably deserve what you get. Unfortunately, the riders behind you don't. Clinchers - can be difficult to change (for mechanical morons) and are always slower to change than tubulars. Most people still carry a spare tube and do their repairs when they get home. - are cheaper to run: if you puncture a lot clinchers will probably still save you money over tubulars, even if you repair your tubulars whenever possible. Tubulars are only repairable most of the time, you virtually never write off a clincher casing due to a puncture. - have improved immensely in recent years; top models now inflate to high pressures, and are lighter and stronger than they used to be. Likewise clincher rims. Some debate over whether tubulars are still lighter and tubular rims stronger. Probably depends on quality you select. No doubt that high quality clinchers/rims stronger, lighter and mor dependable than cheap tubular/rim combination. --------------------------------------------------------------------------- Presta Valve Nuts (Jobst Brandt jobst_brandt@hplabs.hp.com) Two points here: 1. The jamb nut holds the stem when pumping so that it does not recede into the rim when pressing the pump head against the tire. This is especially useful when the tire is flat (after installing the tube). It also keeps the stem from wiggling around while pumping. Removing the nut should present no difficulty unless the threads have been damaged or the hands are cold. The cold may present a problem, but then just opening the valve nut on a Presta valve under such conditions. 2. Breaking off stems with a frame pump comes from pumping incorrectly. The number of new tubes with broken stems lying along the road proves that this occurs far too often. To avoid breaking the stem, the pump head should be be held in the fist so that the pumping force goes from one hand into the other, not from the pump into the valve stem. To practice the correct action, hold the pump head in one hand with the thumb over the outlet, and pump vigorously letting out no air. All the force goes from one hand into the other. This is essentially what should take place when inflating a tire. It does no good to "get even" with the stupid tube by discarding it on the road for all to see. Most riders understand how to pump a tire and see this only as evidence of incompetence rather than a faulty tube. Besides, this ostentatious behavior constitutes littering for which the the fine is $1000 in California. Bike shops should instruct new bike owners about the use of the frame pump. Along with this there should be some tire patch hints like don't try to ride a freshly patched tube, carry a spare tube and always use the spare after patching the punctured tube. Of course this is a whole subject in itself that should be treated under its own heading. --------------------------------------------------------------------------- Ideal Tire Sizes (Jobst Brandt jobst_brandt@hplabs.hp.com) > I'm getting a custom frame built and wondered what > people thought of using 26 inch road wheels. Smaller > wheels ought to be lighter and stronger. and goes on to list advantages and disadvantages, most of which are less that important in deciding what size to use. What in fact brought us the wheel size (700 or 27") that we have is better understood by the women riders who have a hard time fitting these wheels into their small bicycle frames. Wheels would be larger than they are if they would fit the average riders bike, but they don't. So the compromise size is what we are riding today. > It seems to me that the most obvious reason for using 27" > wheels is tradition, but I'm not sure the advantages make > it worth trying to swim upstream. What do you think? This line of thought is consistent with the "cost be damned" approach in bicycling today. The big bucks are spent by people who want the best or even better than their peers. The more special the better. Riders consistently spend nearly twice the money for wheels and get worse rims when they choose anodized ones, whether there is merit to this finish is of no interest. They cost more so they must be better. How "custom" can you get than to have wheels no one else on the block has (maybe 25"?). If enough riders ask for 24", 25" and 26" wheels, manufacturers will up the price as their product lines multiply and the total sales remain constant. Tires and spokes will follow as a whole range of sizes that were not previously stocked become part of the inventory. Meanwhile, bike frames will come in different configurations to take advantage of the special wheel sizes. SIzes whose advantages are imperceptibly small but are touted by riders who talk of seconds saved in their last club TT or while riding to work. A larger wheel rides better on average roads and always corners better because it brings a longer contact patch to the road. A longer contact averages traction over more pavement and avoids slip outs for lack of local traction. Visualize crossing a one inch wide glossy paint stripe with a 27" wheel and an 18" wheel when banked over in a wet turn. I see this subject arise now and then and it reminds me of the concept of splitting wreck.bike into several newsgroups. The perpetrators bring the matter up for many of the wrong reasons. Ride bike, don't re-invent what has been discarded.