OzVMX Forum

Clubroom => Vintage Track => Topic started by: Graham on June 29, 2009, 05:16:03 pm

Title: Tyre Pressure
Post by: Graham on June 29, 2009, 05:16:03 pm
Hi can someone help,first time at dirt track am running a Michelin trials tyre and Michelin knoby front
what tyre pressures should I run ???
Title: Re: Tyre Pressure
Post by: mike1948 on June 29, 2009, 05:57:09 pm
From many years ago, it depends on the track surface, however a good starting point is similar to MX - 15 front & rear, then work from there.  Unlike MX, you may have to increase pressure, if the track is very hard.
Title: Re: Tyre Pressure
Post by: JohnnyO on June 29, 2009, 06:08:26 pm
The dirt track guys run 8 - 10lbs in those michelin trials tyres. Probably run the front at about 12-14lbs, same as mx.
Title: Re: Tyre Pressure
Post by: Graham on June 29, 2009, 06:14:03 pm
Thanks for that, now I known where to start :D
Title: Re: Tyre Pressure
Post by: oldyzman on June 29, 2009, 09:21:49 pm
Hey Graham,
Are you going to nepean for your first race this sunday?
Brett
Title: Re: Tyre Pressure
Post by: Graham on June 29, 2009, 09:32:59 pm
 Hi oldyzman, no got the Double the dirt here in Brisbane 11/12 July, thought I might give the dirt track a go, have a Kawasaki twin, pre 78 and an evo 250
Title: Re: Tyre Pressure
Post by: oldyzman on June 29, 2009, 09:45:11 pm
Good for you graham, I am goin to have a run at Nepean this sunday. with a RM125S and a YZ125E
Not sure about the classes (events) though
Brett
Title: Re: Tyre Pressure
Post by: Freakshow on June 29, 2009, 11:58:04 pm
FWIW , i run 8 psi, if its cold weather i start on 10 psi, after a lap they seem to come on, so im thinking as the walls bend over they heat up and stand up anyway., when i come in there around 12 psi, the michelins like to runover onto the walls and on a speed corner they should be almost like a banana.

too much pressure and they seem to drift out/slip away from you but dont get any drive, you just get the wheel spin. 

IF you find you have to put more than 12psi in cold  to get it to step out and your running short track, put an angle on your rear, winding your outbound wheel adjuster out only, an extra few turns
Title: Re: Tyre Pressure
Post by: allan hughes on June 30, 2009, 08:41:08 am
VERY IMPORTANT
TO RUN HEAVY DUTY TUBES
THAT 20 YEAR OLD 
STANDARD TUBE WONT HANDLE LOW PRESSURES