The Importance of Tire Pressure on Motorcycle Safety and Performance

By John Bolegoh

Tire Problems Need Drastic Solutions

Every year, thousands of accidents are caused by under-inflated and neglected tires. Whether it’s poor handling from a low tire or a serious accident resulting from a sudden blowout, we have all either experienced personally or have had friends who have suffered the consequences of a tire-related problem.

Most riders are well aware of the recent Ford Explorer/Firestone situation that caused hundreds of deaths and resulted in the recall of thousands of vehicles and tires. But not many people are aware of the root cause of these accidents: under-inflated tires.

This tragic incident prompted the U.S. government to create legislation requiring low-pressure warning systems on all new passenger cars, vans, and light trucks. In fact, the legislation is expected to expand to include commercial trucks, buses, recreational vehicles, and, importantly, motorcycles. Other countries around the world are looking at similar legislation.

How Often Do You Check Your Tires?

Proper tire pressure is critical for both rider safety and motorcycle performance. As maintenance studies and any mechanic will confirm, almost 50% of all motorcycle tires are under-inflated, often to dangerous levels. Yes, that’s right--almost 50%. It’s almost a certainty that right now that at least one of your tires is under-inflated, possibly dangerously underinflated.

How often do you check your tires? Once a week, once a month, or just before a big ride? Or are you like most riders and wait until your bike starts to handle strangely? If you’re not checking your tires pretty musch every time you get on the bike, then it’s just not enough.

I’ve spoken with mechanics who talk about customers bringing in their bikes for a servicing because the handling is bad, only to find one or both tires are severely under-inflated. Believe me, they love these customers because all they do is inflate the tires and charge big money for the servicing.

But I Can Tell by Looking!

A very dangerous practice is to judge tire pressure by visually gauging the tire's sidewall deflection (how flat the tire looks). However, with the stiff sidewalls of today’s tires, you just can’t tell by looking. For example, the rear tire of touring bike is likely to appear fully inflated with only 20 PSI (1.4 bar) of tire pressure versus the required 38 PSI (2.2 bar). 20 PSI falls into the "dangerously underinflated" category!

Why Check While It’s Cold?

Because recommended tire pressures are always given as cold inflation values, it is always necessary to check tire pressures when the tires are cold. The pressure inside a tire naturally increases as temperature increases, so checking a tire when its cold is the only way to get an accurate reading that you can compare to the recommended inflation pressure.

Motorcycle tires heat up quickly, so even a short ride to the service station can heat the tires enough to give an improper cold inflation reading. It’s always best to check the tires before you ride and to note each tire’s pressure and how many psi or bars the tire is under-inflated. When you get to the service station, add the corresponding amount air pressure to the tires.

Consult the owner's manual or the placard for your particular model's recommended cold inflation pressure settings.

In next month’s installment, we’ll look at the some of the consequences of riding on under (and over!) inflated tires.

John Bolegoh is SmarTire’s Technical Services Manager with over 25 years of experience in the tire industry. To contact John with a question, email tiretips@smartire.com. SmarTire offers the world’s first active tire pressure monitoring system for motorcycles. For more information, visit www.smartire.com.