Tyre pressures

[captainrob]

What tyre pressures should I start off with at the Phillip Is track day on Monday ? Temperature is forecast for around 15C and they are 20 min sessions.

[Shifu]

What tyre pressures should I start off with at the Phillip Is track day on Monday ? Temperature is forecast for around 15C and they are 20 min sessions.

Do not worry. They will check and adjust it for you at scrutineering stage. Usually around 30-32psi

[Ward P]

What tyre pressures should I start off with at the Phillip Is track day on Monday ? Temperature is forecast for around 15C and they are 20 min sessions.

Do not worry. They will check and adjust it for you at scrutineering stage. Usually around 30-32psi

30psi is a good start point. It'll feel a bit doughy for the 1st lap, but after that !

[BikerBoy]

At scrutineering they always tell me don't go below 33psi because of the extra weight of the busa,
however on your tracky Rob you aren't exactly in need of a diet. Like the others have already mentioned
30-33 should be a good ballpark for you.

[pan]

...or even 28 on those tyres.

[Ward P]

On a hot day I have actually been down to 26psi. If you find it's moving around a bit and a bit slippery once the tyres are warm, they could still be a bit high. But that new surface at PI is just gripgripgrip!

[Driller]

What Bike / Tyres are you using and what lap times are you doing at PI ( ball park )?

[captainrob]

What Bike / Tyres are you using and what lap times are you doing at PI ( ball park )?

Thanks everybody, not to sure how to read the tyres - whether they're over or under pressure. What symptons should i be looking for to tell whether they are over or under pressure?

[Shifu]

What Bike / Tyres are you using and what lap times are you doing at PI ( ball park )?

Thanks everybody, not to sure how to read the tyres - whether they're over or under pressure. What symptons should i be looking for to tell whether they are over or under pressure?

Temperature is a good indicator. If you tyres at about 80-90 deg after a session you pressure is correct

[Ward P]

What Bike / Tyres are you using and what lap times are you doing at PI ( ball park )?

With the new surface the track feels unreal, this is the 1st time I've had a knee down right through turn 1. Running Dunlop Q2s. Had been told by riders at a previous day I probably run around the mid 1.50s but hadn't timed myself 'till the last time in June.
Everyone should download the Pirelli Diable app. It's awesome, give lap times and lean angle plus other stuff.
Using the diablo app on my phone - The old copper, running dead stock and just a track day was averaging 2 min laps, with a best of 1.53. heaps of slower bikes on the track, so reckon it would break 1.50 pretty easy with a clean run. Can't wait to have a go with my new Gen2 in Feb. - I take it we're all gonna do afterburners this year??

[captainrob]

What Bike / Tyres are you using and what lap times are you doing at PI ( ball park )?

With the new surface the track feels unreal, this is the 1st time I've had a knee down right through turn 1. Running Dunlop Q2s. Had been told by riders at a previous day I probably run around the mid 1.50s but hadn't timed myself 'till the last time in June.
Everyone should download the Pirelli Diable app. It's awesome, give lap times and lean angle plus other stuff.
Using the diablo app on my phone - The old copper, running dead stock and just a track day was averaging 2 min laps, with a best of 1.53. heaps of slower bikes on the track, so reckon it would break 1.50 pretty easy with a clean run. Can't wait to have a go with my new Gen2 in Feb. - I take it we're all gonna do afterburners this year??

What's afterburners?

[Driller]

If you are running regular street tyre's start of with a pressure not much down from normal street use 35-38psi reason is street tyre's are designed to heat up quicker than a dedicated track day/race tyre and will offer you more grip after a couple of laps if you drop the pressure to much on a street tyre it will increase the contact patch but wont generate enough heat in the tyre & if your speed isn't up enough all you will do is cold tear it which can look like a lot of tyre wear balling up or a ripping where you get on the power over inflation will feel slippery where it wasn't on previous laps you are looking for a 4-6psi increase from cold to off the track hot (eg 38-44psi) if its lower put more in and visa versa you can chase this all day weather conditions and all hope this helps. Another good idea is have your suspension looked at there will be someone there doing this good investment for a couple of bucks but theres only so much they can do with standard stuff
Also if you havnt got warmers park your bike in the sun every little bit helps
After burners day is held the day after WSBK's I have never done one and after watching one a couple of years ago it was the craziest day no groups just mix it up with anyone out there

[Shifu]

"will offer you more grip after a couple of laps if you drop the pressure to much on a street tyre it will increase the contact patch but wont generate enough heat in the tyre & if your speed isn't up enough all you will do is cold tear it which can look like a lot of tyre wear balling up or a ripping where you get on the power"

I think you got it wrong here mate. The heat in the tire is generated by the friction between bands in the tire as it deforms in contact with the asphalt, i.e. the less pressure the more deflection, the more friction inside the tire, the hotter the tire gets. Also the faster you go, the more friction, the hotter the tire gets. You get cold tear on overinflated tires that can not generate enough heat to get to the optimal temperature (or you are slower than someone that reccomended it for you). That is why the tire temperature is the best indicator for correct tire pressure because it also allows for you speed factor on the track. That is also why they do not reccomend you to use slicks if you are slower rider. For PI that is at least 1:50 before you should consider them. You can ask the guys at Madaz there.

[Ward P]

What's afterburners?

It's the ride day after WSB, An excellent day after spending the weekend watching the races. You can buy a 1, 2, 3 or however many sessions you want, same as regular ride days with categories(white, green, red), but also has a pillion category. A heap of us did it 3 years ago, but I haven't done it since. There was talk of trying to get a group together for Feb '14.

FYI - I will plan for a ride day in December '13 as well.

[Driller]

Yes I was of the same understanding as you until I went through the school of hard knocks & was educated by blokes like Craig White at Bridgestone and basically the larger the contact patch is the harder it is to generate heat the smaller the contact patch the more friction is concentrated in one spot measuring psi is more accurate as opposed to temp mainly because you are only measuring the surface temp and not the carcase you would be looking for an 70-90deg off track but with places like PI being an left hand track you could get 30deg difference from one side of the tyre to the other I have been racing on Bridgestone's slicks now after using Pirellis Dunlops and Michies and my rear tyre pressure's are down to 18psi cold and do 1.40's around EC. I race with Mick from Madaz and reckon he would be of the same opinion Ill ask him next time I see him.