Tyre Pressures

[dwdwdw]

hello all any ideas of typre pressure to use in my beta rev3, the handbook says 0,5 kg/cm2 which is about 7 psi seems a bit low to me. regards Clive

[rev3chris]

3 PSI in the rear

5 PSI in the front

[drop5]

It depends on the conditions ie rocky or muddy, and to some extent on your weight. Down here its mostly mud so I run 3.5 PSI back and 6PSI front. I'm no lightweight at about 16 stone. use a trials dial pressure gauge 0-16 PSI as a normal one is inaccurate at low pressures.

[greg]

3 PSI in the rear

5 PSI in the front

ditto

[scorpa3]

I'm 13 stone and generally ride in muddy events.

IRC rear 4 psi

Michelin front 5 psi

[paul w]

i mainly run on rocky terrain, i am about 16 stone and i set my pressures at 7 psi front 5 psi rear . when the event is mainly mud i drop 1/2psi depending on how snotty it is.

[dan williams]

Seems low until you roll up some slippery nasty obstacle with hardly any wheelspin. Tube rear tires were commonly run around 4-6 PSI. Tubeless are routinely run from ~2.5 to 4 PSI in slippery conditions. It's very common for newbies to run way too much tire pressure and think that the reason they can't find traction in areas where others are just rolling through is a lack of technique. It's always fun to walk up to a new rider and let the air out of their 15 PSI rear tire and tell them to try it again. It's quite literally an eye opener when they ride through some nasty stream bed with their eyes big as saucers. I typically run 4 PSI in dry conditions but will go to 2.5 PSI in really slippery stuff. Remember the contact patch at 2.5 PSI is twice the size as it is at 5 PSI. The common belief is that you get more traction with more weight on the wheel because you increase the friction. That's not quite correct. Above a certain weight there really isn't a significant increase in the friction of tire vs terrain for a given surface area. The real reason weighting a wheel increases traction is weight on the wheel increases the area of the contact patch.

When the radial rear tires first came out they were designed to be used with tubes so they were typically run at a higher pressure to prevent pinch flats. Once the tubeless tires came into use pressure was dropped to the current levels. Although it is possible to damage a rim it really doesn't happen that often. It is much more common to suffer sidewall damage to the tire. Fortunately it is possible to plug a tubeless and I have run tires for embarrassingly long times with a slew of plugs sticking out the side.

So go ahead and let some air out. You'll be amazed what a difference it makes.

[nigel dabster]

4.5 back 5.5 front michelin, re check when warm. fat rider.

[slapshot 3]

5 ps back......6 front complete bloater

[eddie_lejeune]

4 in the back and 6 in the front, we ride rocks and all sorts here, even 3 and a half if you dont mind the odd puncture

scorpa3 are the irc tires any use?

[jimmyl]

4 psi back, always check a few times especially when its been cold overnight. A tire will go up 1 psi or so after it has come out of the van on a spring morning and yes 1 psi makes a lot of difference. Also check after 1st lap if the day warms up.