Your motorcycle’s tires are possibly one of the most overlooked regular maintenance parts of your bike. Are you checking your tires regularly, and do you know what to look for?
A while back, RideApart spoke to Bridgestone Tires’ Engineering Manager T.J.Tennent to get some sensible and authoritative advice on the subject. He’s an avid motorcyclist, and in his spare time is also an instructor for the Motorcycle Safety Foundation. He’s also the Chairman of the Tire & Rim Association’s Motorcycle Sub-Committee, which dictates specifications for the motorcycle wheels, tires and tubes that are sold here in the U.S.
Just like you learned with that “T-CLOCS” (Tires and wheels, Controls, Lights and electrics, Oil and other fluids, Chassis, Stands) acronym in your MSF class, you should give your motorcycle a thorough inspection before every single ride. “That doesn’t always happen in the real world,” said Tennent. “But it should. It’s a bit like being an air pilot carrying out a pre-flight inspection. You should examine your bike from front to end and pay particular attention to your tires. With a motorcycle you only have two wheels on the ground and you should take time to inspect your tires as often as you can.”
Even if you have been riding for years, there are always opportunities to learn more about even the most basic checks to keep yourself and your bike safe out on the road.
First, make sure you have a good tire pressure gauge. They’re not expensive and start from as little as a couple of bucks. An analog gauge is good, and great for your travel kit, but a really good electronic gauge should be de rigueur in your at-home toolbox, since while they take up a bit more space, they are more accurate and easier to use. Hot tip: keep several gauges around, and compare them to each other regularly. They can and will go out of calibration, and this practice will keep surprises to a minimum.
Make it a habit to check those tire pressures—both front and rear—before every ride. Get down next to your bike and really look at them to see if there is any unusual wear or foreign matter in the tread, or bulges in the sidewall. Finding a nail in your tire while you’re still in your driveway beats finding it several miles into a trip every time. If you find strange wear, bubbles, or tread separation and your tires are pretty new, it’s probably worth contacting the manufacturer. You did keep your proof of purchase, right?
“We also recommend that you read the owner’s manual that came with your bike to see what the recommended tire pressures should be,” said Tennent. “But if you don’t have a manual you can find it marked on the sticker on a bike’s swing arm. Failing that, call the manufacturer and get the correct figures.
“Some people like to ride their bikes with reduced psi (pounds per square inch) as it offers a softer ride. But don’t do that. The load bearing capacity of a motorcycle is not in the actual tires but the air inside them. In effect you are compromising your tires, the way your bike handles and possibly your safety.
“The best way to achieve the ride you want is to adjust the suspension. Not all bikes have a sophisticated suspension system but most will allow you to make some adjustments. It’s a much better and safer option than playing around with your tire pressures.”
Tennent also recommends that a rider, especially one who is not in the habit of checking their tires before every ride, should run their tire pressures between one and two psi above the manufacturer’s recommendation. That takes weather changes into account (heat and cold can affect pressures) as well as air loss in an average tire, which tends to lose one psi every four weeks under normal riding conditions.
“Once you have checked both tires are in good condition with no serious wear or damage, you should then do the pressure check. This should always be done when the tires are cold. If you have been out riding, let the bike stand for an hour and let the tires cool off,” said Tennent.
“Move your bike each time you take each pressure reading so the tire valve stem is directly at the bottom of the wheel. Press the gauge as firmly as you can into the stem to make sure you get a good seal.
“If you need to increase the pressures use a regular air pump. Ideally you should be putting in dry air or even nitrogen but that can be an expensive option. As long as the ambient air is dry that should be perfectly fine.” Keep in mind, friends, that our atmosphere is 78% nitrogen, and while a racer might find some benefit to filling her tires with 100% nitrogen, the average rider will benefit much more from simply checking those pressures more often.
The life, in miles, of any given motorcycle tire varies due to a whole lot of factors: the stickiness of the rubber; the weight of the bike (and rider); the enthusiasm with which the rider twists the throttle, hits the brakes, and dives into turns; the road surface in a given area. A sticky sport tire can last as few as 2,000 miles. Keeping a close eye on your tread will give you a good clue about how many miles your tires have left. Keep in mind that running two or even three psi less than the recommended pressures can actually cut the life of a tire by as much as half.
“It may not seem a lot but let’s say you rode with 27 psi in your rear tire rather than the recommended 32psi for an average sport bike... You’re reducing its durability by almost half. Not only that, by running deflated tires you are altering the way your bike handles and performs and ultimately could be putting yourself in real danger.”
If luck does not smile on your ride and a nail or a piece of debris has found its way into your tire, lots of people will insist that the bike should be immediately taken to the nearest motorcycle tire dealer either on a trailer or in the back of a truck for repair. They are not wrong, but those of us who ride motorcycles in the first place have already accepted a certain amount of risk, so this is one more situation that needs some calculation. From our expert:
“If there’s a nail in the tire do not under any circumstances use a rope plug to repair it. There is an option for patch and plug that looks a bit like a mushroom. An expert should fit it, as it fits inside and creates a seal around the material of the tire. In all honesty the best thing to do is replace the tire if it has been damaged in any way. It’s not worth the risk,” explained Tennent.
I, personally, have in fact used a rope plug to repair a hole caused by road debris, on several tires, on several bikes over the years. With each plug, I figure the tire loses one speed rating, and at three plugs (those construction sites will get you every time, and sometimes twice) it’s definitely time to replace the tire. Officially, a tire with even one plug in it should only be considered temporarily fixed. In any case, learn the right way to plug or patch a tire (tubed or tubeless, whatever you run), and it can be the difference between getting home and getting stuck on the side of the road waiting for a tow for four hours.
The official word from our expert: never consider using a car tire on your bike. “A Bridgestone car tire and a Bridgestone motorcycle tire are completely different and have been designed for entirely different purposes. For a start, there are different compounds in both and different traction properties.
“The contact patch on a motorcycle tire is much larger than a car’s. In wet weather with a car tire on your bike you will have less water dissipation and the bike could be fundamentally dangerous. Just don’t do it,’” said Tennent. We know, you disagree; we’re just saying this guy’s a tire expert.
If you like to attend track days with your motorcycles, you’ll learn quickly to pay extra attention to your tires. The folks in charge of tech inspection will not let you on the track if your tires are in bad shape.
“You may also be at a track that has a lot of right hand corners. Consequently you may start to notice a lot of wear on the right side of the rear tire and not the left. Some people have been known to take the tire off and flip it around. Don’t do it. That is potentially very, very dangerous. Motorcycle tires are unidirectional – marked by those arrows you see on the sidewall and are designed to rotate in just one direction. You potentially could have a very big accident as the tire’s material will start to peel and then the tread will come off.”
Yeah, I know, we all know someone who has done it. This one expert’s opinion isn’t your buddy’s anecdote, though. He’s definitely seen some things.
It’s worth remembering that the contact patches on your tires are your only contact with the road. Check pressure frequently and keep an eye on them for wear and tear. Ignore the expert’s opinion at your own risk.
For further information on Bridgestone and the technology it uses to manufacture motorcycle tires go to its web site.
This article was originally published on July 18, 2013 and updated in February 2020.