Mountain Biking - Flats while city riding

Hey,
While I much prefer riding in the woods and on trails, I'm in the city a lot (Boston) so I end up riding once or twice a week here, and probably even more often this summer. The problem is that I've been getting a flat every time I ride, which has yet to happen while I'm riding trails. (knock on wood) Each time it's been my back tire, and there has been two holes or slits next to each other in the tube. I assume it's from hitting curbs too hard and pinching the tube.

Can anyone offer any advice as to how to avoid this? I haven't been riding long, and don't have a lot of technical ability. I can barely jump sideways onto a curb, and when I hit it straight on, my back tire almost always hits. Should I lower air pressure? Avoid curbs all together? Hit the curbs slower? Any tips are appreciated.

Thanks a lot,

John

Yes, those are pinch flats, and they're probably happening because your tire pressure is too low when you hit those curbs.

Why are you hitting curbs? I ride thousands of miles a year in and out of Philadelphia and I can count the number of times I've had to jump a curb on one hand.

Or are you doing it on purpose?

RichC

I concur. Avoid those jumps (or at least take it easy over them) and increase your tyre pressure to the maximum posted on the sidewall. I have NEVER had a pinch/snakebite flat in over 150k km of cycling.

I swear it's potholes that give me my pinch flats. They drive me nuts. It's pure evil. I ride on 120 psi roadie tires and when I hit I swear it feels like my lower arms are going to snap off.

Anyway, that's my little rant.:)

Hey,
I guess I've been riding the curbs a little too aggresively, and overestimating my biking ability and my bike...better take it a little easier.

I don't have a pressure gauge yet, so I am pretty much guessing at air pressure by how it feels.

Thanks for the advice

John

It's normal that you would get pinch flats doing what you are doing. Unless you are running less than 40 p.s.i. I don't think higher pressure will help too much.

For now (so you don't keep getting pinch flats) you should slow down as you approach curbs, get the front wheel up and quickly lean forward a bit, unload the pedals and give the front brake a squeeze so the rear wheel lifts up and over without smacking the curb.

In your spare time, you need to learn to get the rear wheel up while in the air so that you can hop right up the curb at speed. Right after you get the front up, you need to lean forward a little, lift up and back a little with your feet and push forward on a bars a little and twist your hands forward to assist. I'm really no expert on bunnyhops so I will point you to the tips and especially the videos at http://www.trials-online.com/

Practice your high speed bunnyhops with a 2x4 so that if you don't clear it, you simply topple the board over. When you get a little higher, use a small cardboard box.

i find that using good inner tubes helps alot to. I only use Hutchison natural rubber tubes. They are bright green in colour and not very light but the're tough as nails and I've personally found them to be better by far than any other tubes.:beer: