Tire Pressure

[bearfighter]

I was wondering if any one has suggestions on the tire pressure for riding. The manuel says 33 in front and 36 in back, so I was wondering if this is a general suggestion to keep the lawyers happy or should they be inflated higher or lower.

[Ray916MN]

For street riding I'm a believer in following the manufacturer's recommendations. I trust that they are going to make recommendations which maximize performance and minimize risk and have more resources and insight into what works than I do.

[EverydayRiding]

My SV650 says the same, and I follow it for the street. I  lower the pressure when it's below 40F a few psi. On my dual sport, I change the pressure a lot depending on the surface. I lower it for unpaved surfaces quite a bit.

[Lonerider]

What about if I have replaced the tires with other than OEM, and the sidewall of the new tire calls for a differnt pressure? Shouldn't I be following the tire manufacturers recomendation?

[EverydayRiding]

I'm not using OEM tires, and I still follow the numbers on the swingarm from the bike mfg. If I remember right, the numbers on the side of my tires are the MAX pressure, not the pressure you'd want to use.

[Ray916MN]

I'm pretty sure EveryDay has it right that the sidewall numbers represent the maximum inflation pressure for a tire.

There are a couple of instances where I could see running a pressure other than the bike maker's recommendation.

If you're on an SV650 or other light weight bike and run sport touring or touring tires which are implicitly designed for a bike weighing hundreds of pounds more than your SV650, you might want to try a lower tire pressure. Conversely if you load the piss out of your bike (eg. your big, your passenger is big and you carry a boatload of stuff), raising your tire pressure above the manufacturer recommended pressure is probably a good idea. Some owner manual will specifies higher pressures for two up riding.

[vince]

The air pressure that the motorcycle company gives you is for the OEM tire. The air pressure on the side of the tire is for maximum load like a passinger or saddle bags. Now if you go to the tire company web site and look up your bike they will tell you what tire they recommend and what air pressure to use. For a sportbike most are recommending 32 front and 36 rear.

[Tumbler]

The air pressure that the motorcycle company gives you is for the OEM tire. The air pressure on the side of the tire is for maximum load like a passinger or saddle bags. Now if you go to the tire company web site and look up your bike they will tell you what tire they recommend and what air pressure to use. For a sportbike most are recommending 32 front and 36 rear.

That is interesting Vince.  I usually run what it says on the swingarm so I go with 36 & 42.  May have to adjust mine.

[nraforevr]

I addressed the subject of tire pressure in my latest book, Maximum Control. Here is the excerpt:

Tire Pressure

Getting your tire pressure just right for you, your bike, and your riding style is an often overlooked bike-setup adjustment. Lots of riders just leave the tires at the pressures the bike had when they bought it—literally. They never check the tire pressure, ever. Other riders, a little more conscientious about their tires, will at least make a monthly effort to keep the tire pressures at the bike manufacturer’s recommended settings.

If you don’t care about tire pressures at all and don’t want to monkey with them, the manufacturer’s settings are just fine. There is undoubtedly a lot of research done to determine what the optimal pressures are for comfort, stability, grip, and control. Look in the owners manual or for a sticker on the bike that tells you what the (cold) pressures should be. Remember to adjust the tire pressures from these settings if you’re dealing with temperature extremes or carrying a passenger.

[PHOTO 1-7 Close up of tire pressure plate/sticker on a bike.] Caption: The recommended tire pressures are cold pressures, meaning those are the readings you should get after the motorcycle has been sitting overnight, not after you’ve been riding all afternoon. It’s best to ignore the pressure recommendations on the tire itself—those tires will fit any number of bikes. The manufacturer has already taken the tire manufacturers recommendation into consideration, and in some cases, has assisted the tire manufacturer in developing the tire for your particular bike. Remember that the bike-recommended pressures can be considered baseline settings: you have some wiggle room to adjust them more to your liking.

But what if you’re a rider who wants more say in what tire pressures you’re running? Do you have to stick with the manufacturer’s recommendation? Of course not. You can adjust these pressures a few pounds up or down from their OEM operating range. Doing this can make the ride harder or softer, give you better turning feel or better straight-line feel, or give you better grip or increased wear. Generally speaking, the higher the pressure, the harder the ride will be, the bike will be easier to turn, the tires will wear slower, and their operating temperature will be a bit cooler. Lower pressures will soften the ride, make the bike a little more sluggish when turning, increase tire wear and make them run hotter.

To find your optimal tire pressure for your riding style and your bike, start with the manufacturer’s settings as your baseline and ride it for a couple weeks, noting things like the plushness of the ride, how easily the bike turns in low and high-speed corners, and how well the tires feel like they’re gripping the road. Decide what, if any, of these ride characteristics you’d like to change, and change the pressures only 1 psi at a time, and don’t deviate more than 10 or 15 percent from the manufacturer’s recommendation.

For example, if you want to soften your ride, lower the pressures by 1 psi each, then go for a ride and see what you think. If you like the change and want an even softer ride, lower them by another 1 psi and try it again. Eventually, you’ll reach a point in the plushness that makes the bike feel sluggish in turns, so you’ll stop there or maybe add 1 psi to get you the pressure you liked just before you made the fatal change.

Similarly, if you want to make the bike turn a little quicker or easier, raise the pressures 1 psi and go for a ride. If you like what you feel, raise them another 1 psi and try it out. Keep playing with your tire pressures until you have them exactly where you want them in terms of comfort and feel. You can also change the tire pressure in one tire differently from the other, depending on what you’re trying to accomplish. If you want longer wear on the rear but good grip on the front for example, you can decrease the pressure 1 psi on the front and increase the pressure 1 psi on the rear. Play with these pressures for a month or more until you finally believe you have them all sorted out.

Okay, you’ve got your “mental” pressures set—the ones you set based on the way the bike feels to you. Take a final measurement of each tire’s cold pressure and write it down. This is your personal baseline that you can revert back to any time you want. Could we stop there? Sure. But we don’t have to. There are still ways to increase our tires’ performance through pressures settings.

Now, take a look—or rather, a feel—of the ”physical” effects of pressure. Get out on your bike and ride it somewhat hard, combining corners as well as freeway speeds. Get those tires up to operating temperature. From cold, this will take you at least 20 minutes of continuous riding on a warm day. When you’ve got the tires warmed up, quickly park the bike, take off your riding gloves, and immediately feel the tire treads. How’s the temperature? For ideal grip and operating temperature, the tires should feel hot to the touch, but not so hot you can’t hold your hand there. If you have to yank your hand away because a tire is too hot, raise the pressure 1 psi. If a tire doesn’t feel pleasantly warm/borderline hot, or is cool to the touch, lower it by 1 psi. (If you’re not parked back in your driveway, bring a hand or foot pump and tire gauge along with you.

Then go ride for 20 more minutes, and repeat the process. Keep adjusting each tire up or down until, after 20 minutes of riding, each tire is at the perfect temperature. Once you get to this point, check the new pressures first thing the next morning, and write them down. This is your optimal baseline, and it’s probably going to be different from your personal baseline…though it may resemble the manufacturer’s recommended settings.

Your bike’s ideal tire pressures are going to be somewhere between your personal and optimal pressure settings. Now go back and use the first process again, riding the bike to feel for the plushness of the ride, how easily the bike turns in low and high-speed corners, and how well the tires feel like they’re gripping the road. Adjust the pressures again to your liking, but only when the tires are cold, and be sure to stay within both your personal and optimal settings.

Once you’ve got your final pressures established, measure them cold and write them down, noting the air temperature that day, too. If you live in a climate where air temperature changes from season to season, you’ll want to repeat the entire process when the weather changes so you have both cold-weather settings and warm-weather settings. Check your tire temperatures after different types of riding, such as hard cornering at a track day, or long stints in the saddle on a cross-country trip, and adjust as necessary. When you’re back to your normal riding, you’ve got your baselines written down so you can easily revert back the next morning when the tires are cold again.

Pat