track day tyre pressures

[johnnyrod]

I'm never too old to learn something new.... A friend of mine went to Oulton Park the other day with Focused Events, they recommended using lower tyre pressures on the track, I think he went down from about 34/42 on the road to 32/36. Anyone know anything about this, either in general or more specifically for the SV (mine is a curvy with BT101s)? All I know to date is to let out a couple of psi if it's raining to help keep them warm (bit more deformation and so more heat). I had thought that as you're going fast on a track you'd want them no softer than on the road.

The main reason for dropping the tyre pressures is heat. You're going faster on a track day and therefore generating more heat in the tyres, particularly the back one (as it's the driven one).

On the gixer I drop from 36/42 to 32/29 (yes 29). I've had these recommended by the tyre technicians on several track days. I'd assume the same would be true on the SV but probably not as much at the back. For wet track days I don't tend to drop them much at all (couple of psi) or sit in the pit lane being a wimp.

30/32 is what I was told to drop my diablos to on track days

Dropping the pressures for a wet track day is not a good idea. The tread will tend to close up and therefore not disperse the water properly.

Originally Posted by legin

Dropping the pressures for a wet track day is not a good idea. The tread will tend to close up and therefore not disperse the water properly.

nor is it a good idea on the roads.

I did a couple of trackdays and we dropped the pressures to around 30/31psi as advised by the BSB dunlop technician for the reasons stated.

The tyres get a lot hotter on track then they ever will on a road. So as heat expands the air pressure will rise.

Not a good idea dropping pressures on the road for rain, road tyres are designed to run in the wet and dry.

[johnnyrod]

In all honesty I haven't experimented with tyre pressures, the bit about losing a couple of psi to help in the wet was what Focused said to us at a very wet Cadwell last year. I have noticed with my BT010s that if they are sofetr than the usual 32/36 then the steering seems quicker, but not explored the edges of grip. So about 30/32 is the best do you think?

Originally Posted by legin

Dropping the pressures for a wet track day is not a good idea. The tread will tend to close up and therefore not disperse the water properly.

damn...you beat me to it

Race bikes run lower pressures on wet tyres than they do for dry slicks, but road tyres are designed differently.

[I'm not an expert but everything I've heard (except from hearsay) says that dropping pressures on a trackday is not necessary.]

i heard that too.. from a very good source. and explanations. think it was MCN[/quote]