7
Troubleshooting
Check the tire pressure on your bike before every ride; all tires
lose air pressure due to air leaking through the inner tube
or tire casing sidewall. Follow these troubleshooting steps in
order to minimize the time it takes to repair a leaking tire.
Causes of leaks
If the rate at which air leaks from a tubeless tire is excessive,
it can be reduced by repairing the source of the leak.
Use Bontrager Super Juice tire sealant in any UST tubeless
tire to reduce the rate of air loss and add puncture protection.
• If the tire has been ridden, check for punctures.
A small piece of glass or a thorn can embed in the tread and cause a slow leak.
• Make sure the valve nut is tight.
Air can leak around the seal in the valve stem if it is loose or misaligned. If it is
misaligned, loosen the valve nut and gently shift the valve slightly to seat it properly.
Then tighten the nut. However, do not over-tighten it; if you puncture on the trail, you
will have to remove it by hand.
• Check for excessive wear of the tire casing.
This is a problem that is unique to lightweight tubeless tires. The inner liner ply (the
butyl rubber sealing ply on the inner surface of a UST tubeless tire) is as thin as
possible to save weight and it will break down from hard use. The material will form
gaps and these will allow air to escape at increasing rates through the casing. Adding
Bontrager Super Juice sealant will stop this type of leak.
• Make sure all of the critical sealing surfaces are clean and
undamaged.
These include all of the contact surfaces between the tire, rim strip, and valve. Gaps in
the seals due to damage or dirt trapped on any of these surfaces can cause leaks. Clean
or replace any damaged parts.
Checking for leaks
First, visually inspect all of the components for damage or evi-
dence of leaks, and simply listen for the sound of escaping air.
If that doesn’t work, cover all of the areas that might be
leaking with a solution of soap and water, and watch for bub-
bles. With this method, you can also fi nd some leaks through
the tire or between the tire and rim strip near the brake wall.
Use the same soap and water solution that you use to mount
the tires. It’s best to spray the solution on with a household
spray bottle so that it is distributed evenly on the tire surface.
It’s normal to see some bubbles forming through the sidewall
of the tire (a surprising amount!), but a signifi cant leak will
cause a very large amount of foam to form quickly.
Sometimes air leaks into the interior cavities of the rim, and
these can be hard to fi nd. Sources of these leaks include the
