Tire pressure for different surfaces !
 

I am not sure if it is the correct branch for this post ! ?

Hello dear riders,

Would like to hear your experinces and want to find the final truth about "correct tire pressure for different surfaces" like:

(percent of normal air pressure)
* tarmac 100 %
* unpaved 90 % ?
* off road 80 % ?
* gravel 80 % ?
* sand 60 % ?
* mud 80 % ?
* rock/stones 70 % ?
* snow 80 % ?
* ice 70 % ?
* . . .

Especeially experienced riders with different surface ridings, please contribute...

Ride well :scooter:

Samy

I'm not sure you will be able to come up with a definative answer. I used to run 18psi front and 12psi rear on all surfaces. That's a road legal MX or enduro tyre on a DRZ400e with rim-locks.

I run mouses these days and I think the rear is so tired that it would equate to about 8psi. (yes, the back end does squirm around a bit on tarmac but it doesn't bother me)

Be careful not to give yourself too much to worry about.

So much depends on what bike, the load, type of tire and lastly, road or trail conditions.

Correct for what?

Maximum grip?
Maximum tyre life?
Maximum comfort?

Most people who talk/do this are only intrested in grip. They don't care about tyre life or damage.

-------------------
I usually run 100% sealed surface tyre pressure every where .. saves going up and down all the time. I only drop pressure where I really have too (I'm stuck or would be if I didn't).

Reducing the pressure means if you do come across a sharp large surface the rim could be damaged .. increased pressure reduces this risk.

Of course grip and better riding. not tyre life. It's about riding control...

To get better grip it often helps to reduce air-pressure, but it will reduce tire-life, increase risk for punctures and it’s easier to dent the rims. But your bike has very sturdy rims.

Personally I always use 37 PSI unless I there are real troubles. Last time is a few years ago so it’s not often.
The exception is snow/ice where I use around 20-30 PSI.

Racing is a different matter. Around here most people use Mousse anyway so they are not able to adjust.

All valid points.
Different tyres do need different pressure. Trail riding in cornwall, the rear tyre of choice is a pirelli MT43 trials tyre. They have such a high profile that they happily run at 8 psi to give maximum grip on slimey broken slate trails without risking rim damage. The lowest I ever ran one was 2 psi which gave fantastic grip but was squirmy on the road; that was from a slow puncture though, not intentional. Try that with a standard enduro tyre and you would end up with a pinch flat and dented rims very quickly.

Trials tires have gotten very popular

Its whatever the tyre maunufacturer specifies for their tyre fitted to a bike/rider combination of xx kgs on a specific surface.

They've just spent a few $million on developing a tyre so you'd have to expect them to know whats best.

depends, again.
 

yes but if you get good life, you'll have good grip for longer. i'll sometimes go 110% on a good surface to help in this aim.

road temperature and of course the bike's load also influence my decision - on really hot asphalt i'll go higher than recommended, as the tyre then flexes less and hence builds up less heat.

and on soft, deep, especially hot sand, i've had them down so low that the pressure doesn't read on my pocket gauge.

Can't really agree with extending tire life by over-inflation. Long tire life might save you a few bucks, but there will come a time when you need ALL of the available traction that tire has to offer. If you shaved off even 5% just so you could log an extra few clicks, that might be enough to wreck you. The aim with tires should always be maximum traction, not maximum life.

surely not? or we'd all be running race tyres on road bikes for max grip. where as most people run touring tyres for nearly as much grip but a vastly longer life.

I think we're just talking about tyres that are designed for on and off road use but even then you have three basic categories: Road tyres like TKCs which have a rigid sidewall so when the tyre pressure is dropped from the recommended the tyre only deforms by a relatively small amount allowing the tyre to become flatter and give better traction in sand and mud but only to a point. If you drop the pressure too much the tyre will just overheat and the sidewall will break up. Enduro tyres like Michelin Comps are more flexible so you can run then down to less than .5 bar if conditions need it but they are horrible on a paved road at that pressure and wear very quickly. Also, obviously, need rimlocks. Trials tyres are very flexible and are designed to be run almost flat but again feel bad on paved roads at low pressures and still tend to overheat and wear very rapidly. As with everything dual purpose, tyres are a compromise. True road tyres grip the road in a completely different way to the way in which a full motocross tyre finds traction on muddy terrain.

I use 1.5 bar (23psi) front and rear in the TKCs on my GS (no rimlocks) on all surfaces but wouldn't go anywhere near some of the mud I go through on my KTM Exc fitted with Michelin comps 1 bar in the front and .6/.7 bar at the rear.