Yamaha TRX850 Enthusiasts Forum

I recently did a track day and had tyre temp problems with the front losing grip into corners. Not my preferred slides. It got me to thinking do any of you track day riders consider the general temperature when doing track days.

what tyres? What psi? temperature?

Like Phuk says, cant comment without the full info.

Also, was the temp problem with the tyre cos it was too hot or too cold?

A photo of the front hoop after the trackday would be good too.

In a way, yes. I always check tyres after a stint, and depending on what i see, i adjust tyre pressure. I learned something new on the last trackday though. alwyays thought lowering pressure would give higher temp, but with my new tyres (michelin power competition something), which should only have 1.6 cold in the rear, lowering the pressure could mean they run colder... Explanation is due to larger surface that has contact with ground, hence leading more heat to the tarmac. It's never getting easier...

HansJ wrote:In a way, yes. I always check tyres after a stint, and depending on what i see, i adjust tyre pressure. I learned something new on the last trackday though. alwyays thought lowering pressure would give higher temp, but with my new tyres (michelin power competition something), which should only have 1.6 cold in the rear, lowering the pressure could mean they run colder... Explanation is due to larger surface that has contact with ground, hence leading more heat to the tarmac. It's never getting easier...

that doesn't make sense to me? larger surface area creates more friction = heat and the amount dissipated to teh track is minimal (especially as actual track temperature is invariably greater than ambient air.

I

The situation I had that day was clearing showers. The track didn't get a full dry line so we had wet sections. The temp for the day was 13 deg max. I had bt 016s front 30 psi and rear 32 psi. On the day I was riding a slower pace to what I normally do so wasn't keeping the heat in the front tyre. I felt the tyre when I got back to the pits and it was cold. It's the fact I was running so slow that I had the tyre slip. Thats what made me think what do the northerners do for cold days. At what temp you wouldn't ride on a track
I went back a month later and after speaking to the regulars who said this track has excellent wet grip I ran a quicker laps with no problems

phuk72 wrote:
that doesn't make sense to me? larger surface area creates more friction = heat and the amount dissipated to teh track is minimal (especially as actual track temperature is invariably greater than ambient air.

I

I konw, it doesn't make sense to me either, but that was the word from the guy (who BTW was reluctant as well) selling the tyres, who had received the advice from the Michelin guy. I never had any problems with overheating though, so i've not tried it. It goes aginst common sense.

I've never heard this for other tyres, maybe the new design of this tyre differs so much from "standard" design. 1.6 cold is very low for a street tyre (although track biased).

bobtrx wrote: ...
Thats what made me think what do the northerners do for cold days. At what temp you wouldn't ride on a track
...

That's what i do, check tyre surface, and lower the pressure to acchieve higher temp. I've done trackdays in below 10 degrees, and i know that there's been both races and license courses when it's been much colder. There's a limit though, and obviously the tyre temp can't be optimal when it's really cold.

I'm very surprised that road tyres like the 016 didn't get up to temeperature on the track - they are designed to work on the road and in the rain and you will be pushing more and going faster on the track.

I've had race tyres up to full workign temperature within 2 laps even in temps just above freezing

I can only conclude I was riding like an old nanny ( apologies to any old nannies reading this ) and will endeavor to pick up my pace in future

Bob last time i was eastern creek 1 month ago 29 front 29 rear running metzler race techs . Its was a cold shit house morning till mid way into second sesion. no probs with front end grip at all with a front tyre i didnt think id get the full day out off. I run around in B to so im pushing it pretty had to. Getting the right psi can make a big big differance to the way the front will turn mate and grip. the last day i did at oran park my front tyre psi was only 3 psi to high and it was shit front end would just not turn in and when it did it just went into slide mode not a great feeling. I check mine before i go out and when i come back in to see what there doing temp wise. One more note bridgestone's are not worth pissing on ive never liked them . My new k10 gixxer came with them on it pissed them off after only 1500klm. Had no feel from them at all front went were it wanted and the back would let go when ever it wanted hot or cold. I put pirelli supercorsers on it love them totaly differant bike in the way it fells now

Tyres are funny things. If you have confidence in a tyre you will have a good day .Bridgestones are my choice for treaded tyres.I used to get more track time from them and always felt confident. Now I run slicks , I can't speak highly enough of them. and only use treaded in the wet. I think I ran 34 psi because of the wet track , that too may have been part of my problem. Mac Park track is a small tight track and being a wet day I didn't push as much so I didn't get the heat up. I usually set the pressure for the first session and have a look at the tyre after each session. As a rule I don't mind a wet track it makes me concentrate on being smooth etc. Unfortunately that day too slow . Eastern creek , Oran ( rest in peace ) and PI are fast tyre warming tracks so I wouldn't expect to have the same problem there. I will take your advice and check the pressure next time. I think the lowest I have ever run a treaded tyre was 30psi. The slicks have been at 28 psi the last time at Oran. A nice warm day There is always something to learn about bikes.