Tire Pressure On Track

[UrAaYu]

Ermmm...Can someone tell me wad tire pressure shld i use?I'm using BT 39ss fer my front tyre and Michelin pliot activ fer my rear...Btw i'm riding sp...

[stuzztrev]

Originally posted by UrA@yU@February 24, 2007 10:30 am

Ermmm...Can someone tell me wad tire pressure shld i use?I'm using BT 39ss fer my front tyre and Michelin pliot activ fer my rear...Btw i'm riding sp...

You are using for road use or track use? for track u can try Fr:24 Rr:24 or Fr:25 Rr:25..I use tis and its ok for me.. For road use maybe u can try Fr:28 Rr:30..Tis is wat i use for road and its ok..Correct me if i'm wrong..

[UrAaYu]

Oh...On track use...But 25 is it too soft?25 psi?I tink in the past in use 30-31 fer the rear?..Tat day i put 28 or 29 it feels too soft...Not able to corner in high speed will wobble...

[stuzztrev]

Originally posted by UrA@yU@February 24, 2007 06:03 pm

Oh...on track use...

ok...so u going tomoro?

[UrAaYu]

???Tml???

[stuzztrev]

Originally posted by UrA@yU@February 24, 2007 06:11 pm

???Tml???

Yeah...Track Day....

[UrAaYu]

Not sure...U going ar?Still when u going?

[stuzztrev]

Originally posted by UrA@yU@February 24, 2007 06:54 pm

Not sure...U going ar?Still when u going?

yeah going..been playing weekdays..gotta go for track day..riding small bike..jux come along..is fun.. E next time maybe next mth weekdays..go tomoro 1st..

[mystery rider]

Originally posted by 5thRider@January 14, 2007 03:52 pm

I am uncertain about specific "premium" pressures, only a range. But Mark's method is a good way to find out suitable tyre pressures from each individual track and behavior at varying surface temperatures.

 

What I do know is for 600-1000 (sorry to the rest, I'm only a rider). Assuming you use atmospheric air, tyre pressures FRONT and BACK will rise as the air expands after being on the circuit up to a certain point. This optimum(premuim?) level is usually around 35.5-37psi.

 

In 2006, I tested tyres for 3 different tyre importers at PG and these are some things we found out.

 

1. Yes. Mark is right. Set pressures when tyres completely cold. That means before you leave for the circuit, if you ride there. Try to make sure you use an accurate gauge, and to keep using the same one for consistency. Do not set them after you reach the circuit.

E.G. Say your base setting is 34psi. Ride to track, become 36psi. Target is 30psi, so you go ahead and release from 36psi to 30psi or you think "4psi right?",

36-4=32...simple! Not really, unless you know the exact volume of air in there...

 

 

34-30 = 4psi

36-30 = 6psi

36-32 = 4psi also leh... So same as setting from cold?

 

So now which is correct? To be sure ,only the 1st, the other 2, don't know...

It's only simple maths when you set from cold, it becomes physics when you choose to bring other factors in, so let's not.

If you must set at the track. Make sure your tyres are completely cooled(I'm told 2 hours, but never tested as I always set at home) back to at least 34psi before you set your track pressures. That in itself presents another problem, every time you check the pressure, you lose air... So set it at HOME!!! Metzeler Chief Tester recommends the same, "Completely cold please".

 

While race tyres can cool down very quickly, it's to help with dispersing heat to prevent over-heating, it still takes awhile to cool completely. Exactly how long? Good question, tell me when you find out.

 

2. Believe it or not, typical track tyre pressures 29-32psi will ALL rise to around 35-37psi. If they all rise to that mark then why set them so specifically? Reason is the starting point will determine things like how the tyre wears and how consistent the tyre is over 15 fast laps. So this base setting affects how the tyre performs when it reaches OPTIMUM levels of air pressure.

 

3. However,for me, the only reason why I would be checking for "heated tyre pressures" is if you intend to use nitrogen. As opposed to atmospheric air, Nitrogen is inert and does not expand so drastically like air when heated up. Hence, we would set "heated" tyre pressures immediately as you do not need to leave too much room for expansion.

So, you ride hard for 5laps or so, get your Spannerman to immediately check your pressures when you pit in and those are your target/estimated settings for that particular tyre when using nitrogen.

 

4. Whether you are consistent or not, cruising or attacking, tyre pressures will rise to about 35.5-37. Riding at a closed circuit, how slow can you be going? How gently can you be braking? In other words, imagine how often you are accelerating and braking hard? That itself will get the tyre up to temperature, other than the sides not scrubbed-in, the tyre is ready to be used hard.

 

5. In the end, there is no 1-size-fits-all pressure. Rider preference has a great influence over what to set, a rider may sacrifice consistency for out-right traction or choose to ride the bumps out rather than depend on the tyre... May also differ from different manufacturers and different makes. Experience helps alot so try to get a good mechanic whom you can get along with and is as interested in this area as you are...especially if you want to go racing...

 

Sorry for the long post. Can't find any way to shorten...

Hi there 5th!

Just wanna ask is my way of setting presure correctly & 1 uncertain things to ask you..

Hope you are willing to entertain.

 

I thought presure on track should be the rear presure softer than the front from cold tyre?

Cause bike is rear wheel drive and the traction tat create heat are more than the front wheel.. so.. the air in the rear wheel should expand even more then the front is it?

 

My way of setting presure on track!

Assuming i am very confident riding on presure F31 R33 tyre, so.. heat up at about maybe F33 R37 on the rd..

So i believe when i travel from (presure F31 R33) to the track more or less the presure inside had already expand to F33 R37 on plus minus.. Base on F33 R37 presure i run on track for few lap to test out how much more can the presure go up.. Then from there maybe R34 F39 i come back to the pit to release presure to F32 R36 my confident presure.

 

Is my way of setting presure correct?

[5thRider]

Originally posted by mystery rider@February 28, 2007 10:32 am

I thought presure on track should be the rear presure softer than the front from cold tyre?

Cause bike is rear wheel drive and the traction tat create heat are more than the front wheel.. so.. the air in the rear wheel should expand even more then the front is it?

 

My way of setting presure on track!

Assuming i am very confident riding on presure F31 R33 tyre, so.. heat up at about maybe F33 R37 on the rd..

So i believe when i travel from (presure F31 R33) to the track more or less the presure inside had already expand to F33 R37 on plus minus.. Base on F33 R37 presure i run on track for few lap to test out how much more can the presure go up.. Then from there maybe R34 F39 i come back to the pit to release presure to F32 R36 my confident presure.

 

Is my way of setting presure correct?

1. Common for front pressures to be 1-2psi higher. Your observation could be correct, but I do not know any facts why front is commonly higher, sorry. Depending of which make of tyre, I set the front pressure high enough to allow ease of steering and low enough for optimum traction.

 

2. Your way is not wrong, just wondering why you got so many figures... Which exactly is your "confident" pressure? 32/36 or 31/33?

I assume you are riding a 600cc or above machine and using TRACK (M3 etc..) or DOT approve race tyres(RACETEC).Anyway, if you want to set from home...

 

 

(a)Start with 33psi Fr and Rr.

(b)Ride to Track.

©Ride at your normal(i.e. trying to go fast, but safely) pace for 4-5 laps.

(d) Pit in and check tyre pressures IMMEDIATELY.

(e) Lower them to your Known confident settings. In this case, let's say 32/36.

(f) Enjoy the rest of the practice. Reach home, wait 2hrs, check and NOTE pressure when cold.

(g)Next practice, set these pressures at homewhen tyres cold, 1st thing BEFORE moving off to track. Reach track, suit up and have fun.

 

How much your tyre expands can depend on factors like weather, track temp, suspension settings, grade of rider.. etc..Each factor affects by what percentage I do not know. Sorry again. But the range is normally from 35-37 psi front and back when heated up.. good luck...

[299]

Originally posted by NoLogicOne@January 14, 2007 01:41 pm

Charn,

 

Hilary here (Mark's fren). Got a question that was asked by my fren.....

 

He told me he read somewhere, "premium" pressure while tyre is hot and running in the circuit should be 36PSI, so what he suggest is to pit in and measure the tyre pressure after, say, 5laps or so, and adjust it accordingly. After track, when the tyres are cold, he would measure them again at cold temperature and that, accordingly to him is the right way to set pressure for track next time when tyres are cold.

 

Cannot really say I believe him or what, as there's some doubts....the 36PSI "premium" pressure, is it true? Got such things meh?

 

And even if this method holds some truth in it, I believe it's not easy for me to adopt as 1stly, my riding is not consistant, so sometimes I just cruise around only. Secondly, track temp is not always the same temp, but we could easily get an average temp.....

 

What do you have to comment about this Charn? Maybe you heard about this before.

 

i think i hv seen u today at PG.

 

Were u the one riding the red Ducati?

[Dream machine]

hey guy,

 

Can anyone tell mi wat is the air pressure u all using on the track for cls 2 bike... if the tyres using pirelli evo supercorsa, front 120/70-rz17 back 180/55-rz17... i see pirelli factory recommed front 31 back 28 issit good to using the factory recommed air pressure in the pg... can anyone tell mi:smile:

[Rsexxyy]

blah..blah..blah..so the pressure of 30 PSI is set cold or hot??

 

I'm confused..Wat I can remember correctly, an experienced track junkie friend of mine said dat to set the tires cold and at 30 PSI for both front and rear(1000cc).

 

Anyone has got an objection to that??

[gnayed]

That is at cold. But it is best to adjust the pressures according to your riding style.

 

I personally will set about 32 Front 30 Rear cold. Sometimes the track might get alittle hotter or colder, or probably you didn't push hard enough to puff up the tyres, then pit in and adjust accordingly till I get to the desired handling. Then again, that's my personal method of doing things.

[Rsexxyy]

Originally posted by gnayed@April 28, 2007 03:13 pm

That is at cold. But it is best to adjust the pressures according to your riding style.

 

I personally will set about 32 Front 30 Rear cold. Sometimes the track might get alittle hotter or colder, or probably you didn't push hard enough to puff up the tyres, then pit in and adjust accordingly till I get to the desired handling. Then again, that's my personal method of doing things.

So the optimum range is between 35 to 37 psi hot??

 

So lets say after warming up for about 5 laps..u check tire pressure, if not according to pressure u decrease or increase accordingly rite??

 

Ok then come this question..if we were to increase the pressure, the air pumped in will be cold. Won't that affect the PSI reading later after u go out on track?? Cos cold air got the tendency to expand further unlike hot air..

[5thRider]

Originally posted by blade17fire@April 28, 2007 04:00 pm

 

Ok then come this question..if we were to increase the pressure, the air pumped in will be cold. Won't that affect the PSI reading later after u go out on track?? Cos cold air got the tendency to expand further unlike hot air..

That's why we usually start with higher pressures and work our way down... In that case,we don't have to pump in 'cold air"....

[Rsexxyy]

Originally posted by 5thRider@April 28, 2007 04:06 pm

That's why we usually start with higher pressures and work our way down... In that case,we don't have to pump in 'cold air"....

Yup i noe dat..but touch our hearts and ask ard how many riders accidentally decrease too much..hehe!

 

than its like oh..oh..S@#T!!

 

Neway thx guys for sharing..can't wait till July to start track day again..