tire pressure

[GreyGoose006]

just a non biker wondering what kinds of pressure you use in your tires.

i was wondering because with bikes relatively low weight, and big tires, it seems that you wouldn't need to use high pressure. especially when leaning over, the tire has to conform to the road.
but low tire pressures cause wierd tire wear issues.

maybe bikes are like in defiance of traditional rules of car tire pressure, which might be why they are so cool

[richtazz]

Since the tread section on a motorcycle tire is rounded (to remain in contact the road as you lean), there is a much smaller contact patch than the flat tread on a car. Tire pressure is much more important on a bike, that's why I check my tires more frequently on the bike than my car (although I check my car tires once a week too). A low tire on a bike will cause the tread to flat spot, which can cause a dangerous situation when leaning into a corner. As the tire crests the flat spot, it has very little contact with the road when you need it the most.

[jeffcoslacker]

My old hardtail chopper I only ran 10-12 psi in the rear, to save my kidneys...

[BP2K2Max]

i go 34 psi front and rear.

[aussieidiot]

on the track i run 30psi cold. when they heat up they get harder.
street 35 front 38 rear.

a low pressure tyre moves on the rim easier causing a softer ride but a less responsive ride. as you corner it is too soft to get feed back

[GreyGoose006]

thats what i figured.

so i guess grip isnt really an issue... with wide-ish tires and such a low weight.

[DealsGap]

30 front and rear is a common generic pressure for performance riding on street tires. Some race tires have harder carcasses and require drastically different pressures. Pressures vary from tire to tire, type of use, and conditions. Colder temperatures call for lower pressures to allow more flex which generates more heat. The magic number you're looking for is approximately a 6 psi spread from cold to hot PSI readings. Getting pressures wrong has a direct effect on available grip.

[NOBU-SAN]

33 front. 36 rear. 2006 SV650 factory tire sizes. Handling goes WAY off when pressures are not right. The whole bike seems to handle like trash. When they're low anyways. I sometimes keep them a lb or 2 higher than recommended, but that's it.

[UncleBob]

Originally Posted by GreyGoose006

thats what i figured.

so i guess grip isnt really an issue... with wide-ish tires and such a low weight.

this is kinda like saying tire condition isn't important.

Tire pressure is extremely crucial for bikes. Too much pressure reduces contact patch (and thereby traction) but increases longevity. Too little pressure can cause the tire to buckle in extreme example, just like a car tire, too little pressure will cause the tire to concave and "float" on the bead. Or worse case, the sidewall will callapse and the tire will buckle. In a corner, this will spell disaster. Its also worth pointing out, low pressure can greatly increase steering input, because you are increasing the rolling resistance, which aid/hinders turning effort (aka, lean initiation). Some find this disconcerting, even though (assuming its within reason) it doesn't actually effect handling negatively, just increases physical effort required

There are many factors, such as weight of the bike, type of tires used, temp outside, power of bike and riding style, and have no doubt, if you suddenly changed the pressure of someones tires without them being aware of it, and they were used to X pressure, they very well could crash from it if they attempted to ride as they normally do.

to give an extreme example, my SM (a very light bike) I run 20-25psi front and rear. My ZRX (much heavier, and much higher HP) I run 32-38 in the front and anywhere from 25 to 40 psi in the rear depending on what I'm doing and what the conditions are. Higher pressures are when I'm touring in hotter weather. lower pressures are colder temps and/or racing on a track. For example, running the higher pressures on the ZRX in cold weather, will make the bike slide around like its on ice and make it very dangerous.

Many bikers are completely ignorant of tire pressures though, and thankfully, most of those riders are overly cautious/slow by nature. Its the only thing saving them