Why does my tire go flat so often?

Question

My bike tire often goes flat. I road about 20 miles two days ago, and when I was about to ride home, the tire started going flat. This seems to happen often. The worst part is I replaced the inner tube the day before. The tires were also replaced about a year ago and have been barely used. Can the flat be attributed to riding over a large uneven bump in the side walk?

Answer 1

As Kathleen suggested, check the inside of the rim and tire for  intrusions that may be causing the tube to lose air.  If you are not worried about weight you may try adding a protective strip to the inside of your tire. you can also ask your bike shop for heavy duty tubes and/or tires.  Some tires have a Kevlar belt for flat protection.  Make sure that your valve stem is properly sealed and capped. On hot days rubber is more pliable and vulnerable to leaks.  The same internal fix-a-flat goo that you use for your cars is available for bikes. Try Target or a bike shop. Keep tire properly inflated as under inflate tires wear out faster.

Answer 2

There is probably a sharp object in your rim like the end of a spoke or there is a leak around the valve. Look inside the rim to see if there is a sharp object or a hole in your inner tube. If not fill the inner tube with air and spray around the valve with soupy water and see if bubbles appear.

Answer 3

It depends on the tyre- if you're using ultra thin racing tyres then pinch punctures due to going over a pothole in the road are the likely cause. You could buy self sealing inner tubes but they aren't always effective or you can buy plastic puncture resistant strips that go around the inside of the tyre.

Answer 4

Your tires are going flat for one of two reasons:  pinch flats and punctures.  

A pinch flat is where you hit an obstruction so hard that the tube pinches against the rim and tears a hole in the tube.  

A puncture occurs when a sharp object (broken glass, thorn) passes through the tire and punctures the tube.

The solution to pinch flats is two fold:  1) Riding skill: ride more aware.  If you see a hard object such a rut, pothole, or something as small as the lip on a driveway - slow down!  Pull up on your bars just before you hit it so there will be less of an impact.  2)  put less air in your tires or put bigger tires on your bike.  I had a problem with pinch flats on my road bike.  I switched from 23c to 25c tires, did not max inflate them and rode more aware and pinch flats went away.  Even the little one inch curb on a driveway can cause a pinch flat on a high pressure road tire.

Punctures:  the best solution is to put tire liners in your tires (Mr. Tuffy is one brand).  This is a long strip of flexible plastic that sits between the tire and the tube and protects the tube from punctures.  This is the best solution as far as utility and weight.  Two alternatives are self-sealing tubes and stronger re-enforced  'thorn proof' tires, but these tend to be heavy.

Flats are part of biking but you can greatly reduce them.  You should invest in a tire patch kit and learn to patch a tube.  I usually keep a tube until it has about 4 patches on it.  I find the old fashion rubber and glue patches work best.

Also, on a road bike, check your tire pressure before every ride.  A high pressure road tire can lose 20lbs of air in a couple of days.  Mountain bike tires aren't as bad but you should check them at least every couple of weeks.

Answer 5

It's probably your spokes from the inside or your rim causing it maybe a sharp spot on your rim. Try checking that