Internet Surfer 2.0/Internet Surfer 2.0 (Wayzata Technology) (1996).iso/pc/text/mac/faqs.171

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Frequently Asked Questions (FAQS);faqs.171



    pump
    pressure gauge
    flat kit
    wrenches (sizes and type for your velo)
    hex(allen)-wrenches (sizes and type for your velo)
    chain tool
    chain links
    tire levers (plastic)
    spoke wrench
    safety wire
    duct tape
    zip ties

SPARES:
    Again, these fall into "distance from civilization" categories.
For example, that nut that connects your front mudguard to the forks
is essential, but could be fixed with the safety wire until you find a
velo-shop/store that might have a replacement.  Then again, one little
nut is easy on space/weight, and it may be hard to get a replacement if
your velos measurements are non-standard.  If you have a hard-time
finding a replacement for that random part at your local store, bring
one with you.

    inner tubes
    tire-boots
    brake shoes
    light bulbs
    spokes (labeled if different, tied to the frame)
    nuts and bolts for rack/fenders/etc.
    tire (if you're _really_ out there)
    toe-clip strap
    shoe-laces
    cable (especially if yours are longer than normal).
    cable housing (for the shimano special shifter ones)

NIFTY IDEAS:
    Here are some of the better inside tips that I found both
humorous and usefull....

[e-mail] (Mike Johnston)
    A sock (to keep tools inside and for keeping grease off my hands
    during rear wheel flats)

[e-mail] (Steve Kromer)
    The most important article to take along on a long ride
    seems to be faith.

[e-mail] (chris rouch)
    15cm of old tyre

Robyn Stewart <[e-mail]>
    Enough money to get Greyhound home if something goes terribly wrong.

[e-mail]
    bungie cords - you never know when you might want to get that
    set of six beer mugs as a souvenir and transport it on the
    back of your bike.

[e-mail] (Catherine Anne Foulston)
    ZAP Sport Towel.  I think it is really useful because you can
    get it wet and it still dries you.

===========================================================================

Cycling Myths

Following are various myths about cycling and why they are/aren't true.


Myth: Wearing a helmet makes your head hotter than if you didn't wear one.

Actual measurements under hard riding conditions with ANSI standard
helmets show no consistent temperature difference from helmetless
riders.  Part of the reason is that helmets provide insulated
protection from the sun as well as some airflow around the head.
(Les Earnest  [e-mail])


Myth: You need to let the air out of your tires before shipping your bike
      on an airplane - if you don't, the tires will explode.

Assume your tire at sea level, pumped to 100 psi.  Air pressure at sea
level is (about) 15psi. Therefore, the highest pressure which can be
reached in the tire is 100+15=115psi.  Ergo: There is no need to
deflate bicycle tires prior to flight to avoid explosions.
(Giles Morris  [e-mail])
Addendum:  The cargo hold is pressurized to the same pressure as the
passenger compartment.
(Tom ?  [e-mail])


Myth: You can break a bike lock with liquid nitrogen or other gases

Freon cannot cool the lock sufficiently to do any good.  Steel
conducts heat into the cooling zone faster than it can be removed by a
freeze bomb at the temperatures of interest.  Liquid nitrogen or other
gasses are so cumbersome to handle that a lock on a bike cannot be
immersed as it must be to be effective.  The most common and
inconspicuous way to break these locks is by using a 4 inch long 1
inch diameter commercial hydraulic jack attached to a hose and pump
unit.
(Jobst Brandt  [e-mail])

[More myths welcome!]

===========================================================================

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.


===========================================================================

Chains


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  [e-mail])

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.  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 looks
bad but it has no effect on the 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.

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 lubes are better because they have volatile
solvents that allow good penetration for relatively viscous
lubricant.  Paraffin is useless 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 omitted the 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 is not 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 bile, 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 sprockets worn by a longer pitch chain pockets in its teeth.
These pockets are 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 in
its pocket.

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  [e-mail])

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

When you need to replace a Shimano Hyperglide chain, use a Sedis ATB
chain.  It's compatible with the Hyperglide system and doesn't need
a special pin to put the chain back together when you take it apart.

===========================================================================

Cranks and Bottom Brackets

Bottom Bracket Info  (Jobst Brandt  [e-mail])

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  [e-mail])

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 Crankarms  (Jobst Brandt  [e-mail])

[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.

===========================================================================

Tires and tubes

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  [e-mail])

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  [e-mail])

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  [e-mail])

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.

---------------------------------------------------------------------------

Anodized vs. Non-anodized Rims  (Jobst Brandt  [e-mail])

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.