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View Full Version : It's about Tyre pressures.....



spoondc2
12-08-2005, 11:51 AM
Ok.... it starts making me confusing now, so what does the Maximum PSI on the sidewall means? Say it is 42psi, so is this means it is safe to pump the tyre up to 42psi cold? or 42psi hot? Since it is really possible to 'heat up" the tyres to have 10psi differences so... yeah.... what's that really means?

SPEEDCORE
12-08-2005, 12:00 PM
There should be a reading that says MAX psi...... it is more of a guide in a way. Think of it like the company protecting itself from litigation by producing a product with safety warnings etc.

In saying that.... I would rather have a street tyre at a circuit with higher pressure than low..... if that is what you are trying to figure out Alvin. ;)

e240
12-08-2005, 12:01 PM
Ok.... it starts making me confusing now, so what does the Maximum PSI on the sidewall means? Say it is 42psi, so is this means it is safe to pump the tyre up to 42psi cold? or 42psi hot? Since it is really possible to 'heat up" the tyres to have 10psi differences so... yeah.... what's that really means?

It means tyre pressures shouldn't go past 42psi or you risk catastrophic tyre failure. Boom. Hahahah...

Why do you want to pump to the max anyway? You over inflate the tyres, prematurely wear the tyres and lose handling and grip.

On the road, tyre pressures will probably never experience a 10psi change.
On the track however.... when I raced my bike, pressures can go up as much as 8psi, depending on how I ride and the track temperature.

When pressures go up to high, you start losing grip and the tyre become "slippery". In worst cases, the tyre can also fall apart.

wynode
12-08-2005, 12:11 PM
I've just moved this to the new Sussy forum......

DLO01
12-08-2005, 01:07 PM
Each tyre has its own best opperating temp.

If your tyre is too hot and slippery, you need to increase pressure so there is less tyre flex.
Less tyre flex = Less heat.

If your tyre is too cold and slippery, you need to decrease pressure so there is more tyre flex.
More tyre flex = more heat.

You need to find the best pressure to suit the tyre, car, driver, day temp, road temp etc. This is more track sort of talk, does not matter so much on the street.

mj3610
12-08-2005, 01:48 PM
just pump it to 35psi most tyres cope best with this pressure.

pgclee
12-08-2005, 04:42 PM
just pump it to 33-35Psi...for normal road use...so when it heat up, it won't go over 42Psi...

DomenEK
12-08-2005, 04:56 PM
To the best of my knowledge, the Maximum PSI written on the sidewall of the tyre means that is the MOST that tyre can handle safely (hot or cold). Ususally this pressure is quite a bit more than the recommended pressure for everyday motoring. For example I think the Max PSI on my tyres is 60. But the recommended pressure is between 36-40.


just pump it to 35psi most tyres cope best with this pressure.

It depends on the tyre size as well. I know through experience that I have to keep mine (205/40 ZR17) between 38-40psi for optimum road contact/traction.

Ask someone at a reputable tyre place, they should be able to tell you what the recommended pressure is for your particular tyre.

spoondc2
12-08-2005, 06:03 PM
Thanks very much of your help. Just wanna find out what the MAX pressure on the sidewall really means. :D

kousoku
12-08-2005, 11:42 PM
i'm just wondering,
on my door it says recommended tire pressure XXpsi, however on the wall of my tires (aftermarket) it says max pressure zz psi.

quesiton is , is it save to pump up to something similar to zz psi , or should i pump it up to the honda recommended xx psi.

just unsure of wether car types/weights would affect the ability of the tire to maintain and be drivable at a specified zz psi level.

catch my doooriftoo/.?

ONV73C
13-08-2005, 09:09 AM
DomenEK is correct... the lower the profile of the tyre, the higher you want to keep ur tyre pressure.

i keep my 40series at 40psi.