Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > Tyres > Tyre Pressures

[Cobbett]

Certainly the case that specified pressures seem to be notably higher for Jap bikes, never really understood that either.

[PS meant to say 'Diablo Rossos' rather than 'Diablo Rossis' - wishful thinking!...]

[skidlids]

from what I recall all the majority of tyre manufacturers recomend high pressure for road use.
These aren't necessarily the optimum pressure for each type of bike, road condition or riding style. But they know there will be know tyre issues under normal use even when encountering pot holes etc. and therefore you can't hold them liable for say a damaged wheel rim when encountering said pot hole or the resulting accident.

As Chris says on the DD bikes and other race bikes we drop the pressures to below 30psi whem measured cold as these are specific conditions, with the softer tyre caused by the lower pressure it flexis more, the radial belts move over each other more, causing friction and hence heat which in turn raises the pressure.

Many track tyres use compounds that rely on running hot to allow them to grip as designed and lowering the pressures allow them to get to these temperatures quicker, either that or use tyre warmers. Now you may put the warmer onto a cold tyre at 28psi but when its properly warmed you will probably find the pressure has rissen to around 34psi.
On the roads its hard to keep the heat in these sort of tyres and once they have cooled and the pressure dropped you wouldn't really want to encounter a pot hole especially if your using Mag wheels as i do on my 998 hence me usually running road tyre pressure when cold of 32 psi

[Monty]

John, I always ran my ST4S at 32F/36R unless on track when I dropped to 30 F/R. I always found the ST4S would feel a bit 'vague' on the steering with higher pressures.
When we were racing the TZ250 that ran at 36psi F/R-HOT-straight out of the warmers. Those pressures are on slicks and with a bike weighing 103kg don't forget.

John

[skidlids]

Originally Posted by Monty

When we were racing the TZ250 that ran at 36psi F/R-HOT-straight out of the warmers.
John

I recall a Pembrey meet where they were a fair bit higher than that John

Poor WJB found out the hard way

[John W]

Thanks guys.

Hopefully the ST won't be doing any more trips if the new MS1200 turns up in time. If I do still use it I'll try your pressures John.

I'll run the MS at the pressures specified in its manual and see how I get on.

Thanks again.

[Monty]

Originally Posted by skidlids

I recall a Pembrey meet where they were a fair bit higher than that John

Poor WJB found out the hard way

True-but then he was the one who set the pressures-or rather didn't check them.....................3 times he chucked it down the road that weekend-first race meeting-talk about a baptism of fire.

John

[WeeJohnyB]

Originally Posted by Monty

True-but then he was the one who set the pressures-or rather didn't check them.....................3 times he chucked it down the road that weekend-first race meeting-talk about a baptism of fire.

John

That has to have been one of the worst meetings ever. Sleeping in a puddle in a tent. Strong winds throwing peoples gazebo's down the paddock. Rain and dry in the same race. Slicks or inters or wets. You working half the night to fix the bike. Holbeach changing to the inters tyres and as I now know, he always over-inflates to get the tyre to seal properly, but some idiot (me) tried to make a change 30 seconds before the race and didn't check and after falling off at the fast right hander checked to find the tyres at 45psi. To be fair the other off was on oil and I was not the only one to go down on it. Can't recall the third off, maybe that's a good thing. That was a long drive home eh

Happy days

WeeJohnyB

[jerryz]

for years i ran 32-33 in the rear of my S4 and m750 and 30 in the front but recently have been putting 34-35 in the rear and 31-32 in the front and it has improved both bikes ,they turn in and hold lines much better.