Tire air pressure question.?

For optimum performance and mileage (I realize these may be independent of each other) do you run the tire at the tire manufacture's air pressure rating or the motorcycle manufacture's rating?





For example MC's rating is 33 front / 36 rear. Tire manufacturer's ratings are 38/42
Tire air pressure question.?
Motorcycle manufacturer's figure is set for OE tyres, tyre manufacturer鈥檚 are tyre specific, although they might advertise the pressure for your specific bike 鈥?follow the tyre manufacturer鈥檚 advice.
Tire air pressure question.?
Its all about friction. The higher the tyre pressure the higher the mileage, but you compromise on ride quality. The lower the tyre pressure lesser the mileage. Ultimately, it depends on what you want.
Reply:I'd go with what the tire says. there's no way the MC can say what pressure every tire should be at.
Reply:Look closely at the tire. Those rating are MAXIMUM air pressures. Use the m/c manufacturer rating . Using the 38/42 will result in a stiff ride and possible tire failure. Remember the Ford/Firestone lawsuits? This is what it was about. I have worked in both the auto and motorcycle industry, you are risking your life by over inflating!
Reply:Ok, the tires say 38/42. Those pressure ratings are the necessary air pressures needed for the tire to support the amount of weight shown on the load rating. For example, if the rear tire's load rating is shown on the sidewall as 735 pounds, it'll need 42 psi to support that load. If you have a heavily loaded touring bike and both you and your rider are 200+ lbs, then you'll probably want 42 psi.





However, if you have a bare bike and you weight 120 lbs soaking wet, you'll never ever come close to having 735 lbs on the rear. If that's the case, it's best to lower the tire pressure to say, 36 psi. That will let the tire flatten out some and put more tread on the pavement, giving you better traction AND longer wear. More air pressure than needed for the load forces the crown (center) of the tire outward, giving it a peaked shape. That puts less rubber on the road which means less traction and shorter wear life. It doesn't matter how much tread you have left on the outsides of the tire's tread, if the center is bald as a baby's butt, your tire's shot.
Reply:Tire people tend to know about tires. Besides this isn't apples and pears. More important is to check the pressures routinely.
Reply:The M/C rating is good for that bike. Basically the best pressure for normal street use. For optimal grip use will use a lower pressure that will vary for given conditions, one problem with running lower tire pressures is they will react abit squirrelly until they get up to temperature. Think track riding for that or serious fun run. You will get better mileage out of tire running higher pleasures, I read somewhere that you will get 1.3% per foot pound but you can only go as far as the sidewall is reated for. Also keep in mind that you will be sacraficing grip with the higher preasures.





All of the screwing around is not worth it to me, differant tire preasures affect the way you will want you suppention set-up as do differant tires. I constantly run my rr at the recommended tire by Honda but run my f4i 4lbs low, but this bike is mainly set-up for the local track and rarely sees the road anymore, just every once and awhile.





Mileage should be negladgeable on a bike so why suffer grip at for a few dollars saved.
Reply:I always use the vehicle manufacturer's specification.


The manufacurer will specify a rim size, a tire size and a pressure. That is the recommendation for that specific motorcycle. Notice that there is usually a second pressure for riding double.


The numbers on the tire sidewall are max pressure at max load for that tire. Notice these are always maximums.





Since we're talking motorcycles, I'll use this example:


My Honda 750 and my Harley Dyna can both take the same tires. In that case, the numbers (on the tire) will be the same, agreed? The Honda has lower pressures listed. This corresponds to the lower load placed on the tire by this motorcycle. The Harley has higher pressures, as it's weight is higher. The result of the different pressures used on these two different motorcycles with the same tires is: the tire profile remains the SAME in both cases. As you have hinted, change in pressure = change in profile, contact patch, and wear.





The consequences of running tire pressure higher than the motorcycle manufacturer's recommendation are harsh ride, rapid center wear, decreased handling/grip.....