We’ve all been there; you’re out for a ride on a beautiful day and we notice your bike is handling sluggishly. You look down and there’s the answer- you have a flat tire. Hopefully you have your cell phone or are within walking distance to a bike shop. But the culprit may not be as obvious as you might think.
Conventional wisdom tells you the first thing you do when you get a flat tire is check the tread for foreign debris, such as a nail or shard of glass. But with bike tires designed as resilient as ever, especially mountain bike tread, this typically accounts for less than half of bike tire flats.
Never is the tire- the outer rubber ring- being punctured the sole reason you have a flat. When you have a flat tire, whatever the source, the reason is your inner tube has been punctured. A tire unit is designed to withstand puncture to the outer tread and retain air without the inner tube being compromise. It’s only when objects penetrate the inner tube will you experience the misfortune of a flat tire.
If you have ever had your wheel trued, and soon thereafter notice a slow leak in your tire, you will want to take it back to the bike shop as soon as possible. This is because whoever trued it basically did it incorrectly. Most likely they didn’t secure a spoke and it is protruding through the rim and causing a slow leak. How slow the leak may be depends on how deep the errant spoke extends.
You may also have a slow leak thanks to a poorly installed inner tube. Everyone who rides a bike thinks they can install an inner tube properly. In fact, there is an exact science to installing an inner tube, whereby the installer has to insure it is properly seated in the rim. Also ensuring the valve stem sits exactly perpendicular to the rim prevent slow air leaks.
Improper installation is the source for slow air leaks more often than not. Making sure your bike maintenance is in the right hands or you are very well educated on the matter is imperative to avoiding issues when you’re on the road. Otherwise you could find yourself stranded.