Motorcycle Tire Pressure: Who Said Inflation Was Bad?
Checking your motorcycle tire pressure is a very important part of your pre-ride checklist. It is the last thing that a lot of motorcyclists think of when they want to go out for a quick ride or run to the store, but if it’s not right, you can have problems.
Keeping your motorcycle tire pressure too high reduces the size of the contact patch, which reduces the amount of grip available.
If it’s too low, the carcass of the tire can flex too much, causing poor handling and extra heat being put into the tire, which can shorten the tire’s life.
How often should you check your motorcycle tire pressure? You should really follow your manufacturer’s recommendations on this. Most motorcycle manufacturers are going to recommend that you check your motorcycle tire pressure daily and adjust as required. Most people don’t do that, but that is the recommendation. If you check your motorcycle tire air pressure once a week, you’ll still be doing better than 95% of all riders out there.
Tire pressure should always be checked when the tires are cold. This means before you ride or if it has been parked for at least 3 hours. Tires heat up when riding and the air pressure increases as the temperature increases.
What pressure should you inflate your tires to? If you answered, “to the pressure listed on the tire sidewall,” you’d be wrong.
If you will be loading your motorcycle or riding with a passenger, you will need to increase the air pressure in your tires. This is when you should inflate the tires to the maximum listed pressure on the tire sidewall.
Nitrogen fill? Over the past few years you may have heard about filling your tires with nitrogen rather than simple compressed air. So, what’s the deal there? According to the Get Nitrogen Institute (www.getnitrogen.org), filling your tires with nitrogen will improve fuel economy, increase tire life, and will improve vehicle handling and traction. They build the case for those claims, but my intuition tells me that most of the claims are, er, overinflated.
I will concede that the claim that the larger nitrogen molecule permeates the rubber of the tire more slowly than an air molecule, so the nitrogen filled tires will hold their pressure longer. I do know that different rubber compounds have different gas permeability rates, but I don’t think anyone has done definitive studies on the relative effusion of different gases through tire rubber. Even so, I will also agree that the nitrogen used to fill tires is dry and that compressed air always has some amount of water/moisture in it, which can lead to rim corrosion. The oxidation inherent with water and moisture can also affect the tire rubber itself over time.
The fuel savings of 4-10% they claim seems a bit optimistic to me, however. There are no definitive studies on this, and certainly none that studied motorcycles specifically, so you’re going to have to make up your own mind. But, assuming the slower loss rate part is true, it must have to do with the fact that most people rarely check their tire air pressure, so tires filled with nitrogen stay at the optimum pressure longer and therefore save gas.