Air Head: Tire Pressure 101

Back when I was young I rode on rigid steel frames and if I wanted a smooth ride I dropped the tire pressure, I also rode without a helmet so that should tell you something about my knowledge back then.  It takes some experience to realize the significance of tire pressure so for those who don’t have the seat time, take a little advice when you can get it.

Tire pressure can make a world of difference even to the most inexperienced rider.  Perhaps you’ve noticed a swaying sensation on your bike at one time or another, this could be directly related to the tire pressure you’re running.  On uneven terrain or at certain speeds tire pressure can be critical even dangerous.  Tire pressure can also make the difference between a smooth or bumpy ride especially if you’re riding on a hardtail frame, a lesson I learned a long time ago.

So what is the ideal tire pressure?  The folks at Schwalbe say it's difficult to make a general recommendation on inflation pressure for a specific bicycle or a particular tire.  The “right” inflation pressure depends mainly on the load exerted on the tire.  This weight is mainly influenced by the weight of the rider.  Contrary to a car, the vehicle weight is only a minor part of the total weight.  In addition there is a great diversity of individual preferences with regards to low rolling resistance or suspension comfort.

You’re probably asking yourself now at what tire pressure do I start?  The permitted inflation pressure range is marked on the tire sidewall.  The higher the inflation pressure, the lower the rolling resistance, the tire wear and the less likelihood of a puncture, the lower the inflation pressure, the higher are the comfort and grip that the tires provide (Schwalbe).  So now let’s try and figure out our ideal tire pressure or something close to it.

Let’s start by using the typical 26X2.1 inch mountain bike tire (the bigger the tire the lower psi you’ll start with).  For most recreational riders start as if you weighed 100 pounds.  Inflate to 27 psi then add 1 psi for every 10 pounds over 100.  For example, if you weigh 150lbs, start by inflating to 32 psi (27+5=32).  Please remember that tire pressure is a personal preference so use this guideline as a starting point and adjust your tire pressure to your own specifications.

According to the tech gurus at Mountain Bike Action, in general you want to run the front tire 2 to 5 psi lower than the rear to help with front tire traction.  On loose terrain you may want to drop the pressure from both tires 1 to 3 psi.  On the other hand, if your trail is hardpacked or rocky, adding 1 to 3 psi will increase your performance and provide a little more protection for your rims.  One to 5 psi can make a difference but for most recreational riders the difference is negligible.

Here’s another helpful tip: Don’t drop your air pressure on the trail if you don’t have a pump.  It's fairly common to adjust tire pressure during a ride but if you’re unable to bring your tire pressure back to normal you may be increasing your chances of a flat.  It seems like a no-brainer but it happens to the best of us.

A tire pressure gauge is an essential item in any tool box and any type will do.  So now you have a little tire pressure knowledge to help you get the most out of your rides.  Don’t forget to check for trail updates on my website at www.dirt-life.com.

There are no hard fast rules about tire pressure so if you have any comments or suggestions please don't hesitate to post your comment.  I hope this was helpful and don't forget that pump; see you on the trail.

Alan