Get the correct size tyre
The markings on a tyre sidewall are to an
internationally recognized standard called ISO - there
are two numbers (eg 37-622). The first number refers
to the section of the tyre, the second is the bead
diameter in mm. An imperial equivalent is often shown.
Make sure you know what size tyre you need before
asking your shop for a replacement.
Tyre widths vary greatly. MTB tyres are available in
sizes up to 2.3 in wide. A tyre like this offers a
shock absorbent aspect needed for the rigours of
off-road riding. By contrast road race bikes need to
cheat the wind with narrow tyres. A 20mm tyre is
popular, though 25 mm tyres, which provide greater
comfort for long spells in the saddle, are the popular
choice of many cycle tourists.
Get the pressure right
Tyres lose air, so be prepared to inflate. Latex
tyres are particularly prone to go down between rides
as they are porous. Give your tyres a squeeze before
you go for a ride and …. If in doubt check their
pressure with a gauge. Be careful not to exceed the
recommended limit, and always follow the
manufacturer's suggested pressure.
Puncture repairs
Puncture repairs are straightforward if they are due
to an intrusion such as a thorn, but those caused by
impact - sometimes called a pinch flat - are
difficult, if not impossible, to repair.
Here's how to identify an no-hoper and fit a new inner
tube.
- The inner tube has a snakebite puncture and is
beyond repair. It's been caused by the tube
compressing into the rim. Latex tubes, however,
are almost always repairable.
- Remove the tyre and tube then carefully inspect
the bed of the rim for sharp objects and any
protruding spokes. Replace the rim tape if it's
damaged.
- Fit one side of the tyre over the well of the
rim. Inflate the tube so that it is firm, then
place the valve through the hole.
- Working from waist height downwards, work the
bead of the tyre over the rim using your thumbs.
- Use your thumbs to manipulate the tyre over the
inner tube.
- Inflate the tyre to seat the bead. Do this
slowly and check that the tyre bead isn't bulging
out anywhere.
- Finally, inflate to the recommended pressure.
Tips
- If you are getting ready for a race it's as well
to inspect the inner tube, as an unstuck patch can
wreak havoc on your chances
- If you were riding fast at the time of the
puncture, examine the sidewall of the tyre for
damage
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