Tyre Pressure

[Paul Freemantle]

What tyre pressure should i be running on the 172 with standard wheels

 

[BenR]

i run 30 as the rd are very bumpy.

but it depends, i can feel fine on 28psi, the tyre wall is small anyway. But some people dont feel safe until 35psi.

Test and see, the airs free!

 

[BRUN]

yea, i like higher pressure myself, its a bit bumpy at times but the grip on bends seems to be better

wheel size doesnt matter as its pressure, which isnt a measurement of the amount of air

i use 36 front and 34/35 rear....

just give it a try an see what you like best

 

[rockport]

can someone advise me how having more PSI pumped inyour tyres gives you more grip?

i always thought :-

the less pressure the better the grip, the more tyre wear (hence drag racers having such low tyres, or is this becasue the air expands at high speed)

im confused now..

 

[Rick]

I read something a while ago about lads who were jacking up their tyre pressures to around 55-60 psi so they could do burnouts/hand brake turns easily. The only problem was, once they were out on the road they had no grip at all and were writing their cars off!!!!

 

[Fred@BTM]

The tyre place that did my tyres had to put 110psi into my tyres to get them to pop onto the rims!!!!!!

 

[Nagra_mk1_172]

I think the basic princple is this:

If you over-inflate your tyres, the middle wears out quicker

If you under-inflate your tyres the shoulders wear out quicker

Is this right ?

 

[rockport]

Quote: Originally posted by 172_geek on 13 March 2003


I think the basic princple is this:

If you over-inflate your tyres, the middle wears out quicker

If you under-inflate your tyres the shoulders wear out quicker

Is this right ?





sounds logical.... still dont know how the grip thing works tho.

 

[Tom]

ok what you do then is

do the first 20,000 with high pressure

do the next 20,000 with low pressure

double the lifespan of yo tyres!!

 

[RPM]

Lower pressure means more grip. At least in a straight line. It allows the sidewall to flex thus reducing the tendence to spinn your tires.

Lars

 

[rockport]

Quote: Originally posted by RPM on 13 March 2003


Lower pressure means more grip. At least in a straight line. It allows the sidewall to flex thus reducing the tendence to spinn your tires.

Lars







thats what i thought, however :-



Quote: Originally posted by BRUN on 13 March 2003



yea, i like higher pressure myself, its a bit bumpy at times but the grip on bends seems to be better







Dont know what to believe now...

 

[BRUN]

try it fo yourselves, ive never had a problem with straight line grip, but i swear my car goes round corners a lot better with 36 - 34 than with somethin like 32 - 30

it might be the tyres im runnin i dunno ?

 

[pep 87]

Try running a bit lower for wet weather!! and a bit harder in the dry.

 

[Mrdemon]

you need a tyre temp gauge.

what you are after is a uniform tyre temp across the whole tyre.

messure at 3 points outer middle and inner.

you need to play around abit as different makes of tyres need different pressures.

if you do have them to hard wet traction will be undrivable but you will get more mpg on the motoway.

what sort of driving do you do ?

 

[BenR]

i made the ref to a smaller side wall as there is less flex, thus you dont need such high presures to keep a tyre stiff.

Lower tyres simply increase the tyres ability to deform the contact patch, drag races use low pressures as it increases the contact patch. and 1/2 the gearing of a drag racer is in the expansion of the tyre.

32 is fine.....

 

[BUTRE]

I tried a couple of times (dont know how to right it, but here it is the chemical symbol of the gas) N instead of air. And thats not free!

didnt feel the promised less tyre deformation caused by heat, only a smoother overcoming on road bumps.

 

[BenR]

nitrogen