Last blog I wrote to technical guru Lennard Zinn to ask the best tire pressure to avoid slit tires. Boiled down, my question was:

Q:  If I ride a course that is littered with shale and I want to avoid getting a slit in my tire, does tire pressure make a difference one way or the other? Using a balloon and pin theory – if I poke a fully inflated balloon with a pin, it pops almost immediately. If I poke a half inflated balloon with the pin, the balloon gives quite a bit before failure. One argument is that I should keep running my low tire pressure. Another theory is that more air in the tire may have deflected the shale not allowing it to sink into and slice my sidewall.

So, when running tires on a shale and rocky course do I run more air than normal, less air or run “normal” pressure. (“Normal” being what I would run for a rocky course, sans patches of shale.)

Also, is there any scientific evidence anywhere (that I couldn’t find)?

Here is Lennard’s reply:

A:  Wow. Good question! Unfortunately, I don't know the answer. My guess would be that the lower pressure would probably reduce punctures more over the long term, but I have no scientific data to back that up; it is only a hunch.

Thanks for your question for my column.

Keep the wheels turning,

Lennard Zinn

President, Zinn Cycles Inc.

Senior Technical Writer for VeloNews

Author of bike maintenance books and other books

7437 S. Boulder Rd.

Boulder, CO 80303-4641 USA

ph. 303-499-4349

email  veloqna@comcast.net

www.zinncycles.com