Puncture – this is the variety of flat most people think about first… essentially running over something sharp. You may or may not feel or hear anything, and air may leak all at once or very slowly. The main thing I’ve learned to help prevent this type of flat is to use a quality sealant like Flat Attack. It only adds a few ounces of weight, and is an inexpensive insurance policy against a thorn or piece of glass wrecking your day.
Pinch – a pinch, also known as a “snakebite”, occurs when the tube literally gets pinched between the tire and the rim of your wheel. I put new tires on my bike a couple weeks before IMSG 70.3, and for some reason I had a really tough time getting them on. I was grunting like an Olympic power lifter, and my fingers were blistering up by the time I got the suckers on. A small part of the tube was jutting out of the tire, and I had to massage it back inside with a tire lever. My theory is that unbeknownst to me a tiny piece of the tube was still slightly pinched in there. At mile 37 with the heat rising in St. George, it decided it had had enough. Further evidence of a pinch is a loud bang, like popping a balloon, which is what happened in my case. So… to avoid this I’ve learned two things: 1) after you change your tire, go around it and look carefully… if you squeeze the tire together and can see any tube at all, it’s pinched in there. Start over. 2) If you’re struggling to put on new tires (or changing an older one) sometimes it’s worth $5 to swallow your pride and have the kid at your local bike shop do it for you!
A pinch can also occur if you aren’t watching the road and hit a big pothole, train tracks, or something else really hard. You’re more likely to flat in this situation if your tires are under-inflated, so it’s good to pump them up before each ride (I pump mine to 110 psi on tires that have a max of 120).Tires – an old, worn-out tire is more vulnerable to flatting. When in doubt put that thing on your trainer and get new ones for the great outdoors.
Rims – this isn’t an obvious one to beginners, but your rims can be really sneaky sometimes. Two years ago my wife flatted 4 times in a row attempting to pump up her tires in transition before her race. Some good samaritans gave her spare tubes, but she just kept inexplicably flatting. Eventually someone discovered a sharp edge on one of the rim holes that was poking through her rim tape. Thankfully a piece of electrical tape did the trick, and she was able to race. Afterwards she got a longer-term fix by having the rim tape replaced.
Check your rim tape every now and then to make sure it’s effectively covering all of your wheel’s rim holes, and replace the tape when it gets ragged. Another solution that I use (that the Flat Attack guys introduced me to), is a product called Veloplugs. Veloplugs were invented in Australia and are essentially a superior solution to rim tape. They’re lighter, make it easier to change your tire (eliminating rim tape creates more room in the rim well to work with), and once installed never need to be replaced. Regardless if you use rim tape or Veloplugs, take a gander at your rims every now and then.
Flatting is a part of cycling, but hopefully these tips will keep you riding more and muttering obscenities on the side of the road less!