| Author |
 Topic  |
|
Alain Pineau
France
13 Posts |
 Posted - 25/05/2012 : 11:28:12
|
Could someone tell me what is the good tyre pressure for a PA ?
Mine is a tourer ( is it different from a roadster ? ) .and roads around Paris are sometimes really bumpy ! Is 1.8 bar too much ?
|
|
|
Alain Pineau
France
13 Posts |
Posted - 25/05/2012 : 11:51:12
|
| Just to precise : 1.8 bar = 27 psi :) |
 |
|
|
David Allison
United Kingdom
665 Posts |
Posted - 25/05/2012 : 12:56:23
|
Alain
That sounds a bit low to me - I normally start at 30-35 psi and go down from there for road use.
Regards David |
|
|
|
Alain Pineau
France
13 Posts |
Posted - 25/05/2012 : 13:15:57
|
OK David, thank you !
I will try 30 for front and 35 rear...even if already the car shakes us in every way !
Hope it will may be improve also the steering at high speed :) |
|
|
|
George Eagle
United Kingdom
3246 Posts |
Posted - 26/05/2012 : 11:12:12
|
Hello Alain
I have found that 28 all round is about the best for my cars, I think 35 would be too high.
Incidentally, I have found that at 28 psi the Blockleys on my NB do not form flats.
George
L2023 and NA0960
Nr Buckingham, UK |
|
|
|
tholden
United Kingdom
1641 Posts |
Posted - 26/05/2012 : 14:58:48
|
Using Avons on J and P types in particular I have found through experience that 30 /32 lbs is right for our cars for general road use. Depends how you like your steering and ride to feel. Any higher can be a bit difficult in the wet and adds nothing to the general handling. Not yet had much experience with Blockleys although others have said they are better at slightly lower pressures as George suggests.
Have just finished a Blockley shoed car on 4.50 x 19's so will see how it handles.
David you seem to be getting a bit confused again recomending 30- 35 here and 40 elsewhere.
TH |
|
|
|
Gordon
United Kingdom
693 Posts |
Posted - 26/05/2012 : 15:11:03
|
I am using Blockley 4.00 x 19 on a 2 seater PB. I started off at 30 psi but found the side walls bending under cornering loads and giving marked roll induce oversteer. On David's advice I have put them up to 40 psi and this has made an enormous improvement in the dry. I have yet to experiment with a gradual lowering of pressures. I do not find the ride is any harder with the increase from 30 to 40 psi. I think it is a bit easier to lock the brakes which might point to Terry's comment that wet conditions may need watching. More careful experimentation called for!
Gordon
PB 0331, MG4473
Derby |
|
|
|
spitfire
United Kingdom
371 Posts |
Posted - 26/05/2012 : 15:41:23
|
I'm watching these comments with interest. I have a J2, but the PA tyre pressures quoted, plus the positives for 40 psi is something worth taking on board.
Gordon's comment on tyre wall flex. Why are cars now sporting low profile tyres? Motorcycles the same. My MGAs were always very happy and nimble with a few more psi onboard.
After all, this is the point where driver and machine interface with the road surface.
Would be interesting to photograph tyres on cars at incremented psi amounts. Seeing when they sit flat, become rounded. |
|
|
|
Alain Pineau
France
13 Posts |
Posted - 29/05/2012 : 17:44:06
|
Thank you all,
It is true that the correct pressure is a good topic !
If it's underinflated tire slumped in the corner and handling is poor, if it is over-inflated the frame and suspension are too much stressed
and this is probably not good either ....
While 27 to 40 psi there is still margin!
My tires are Dunlop little worn but still have 20 years
I'm going to experiment, because I understand as suggested Spitfire this is pretty subjective.
However, if others have clarifications, thank you very much! |
|
|
|
Simon Johnston
United Kingdom
6186 Posts |
Posted - 29/05/2012 : 22:15:09
|
The August 1933 edition of the Instruction Manual for the J (illustrated with a swept wing car, so not so dissimilar to a P type in weight) gives the recommended tyre pressures as 32 p.s.i. all round. But then goes on to say that "when rear seats are occupied pressure should be increased to about 30 lbs"!
P.S. I don't think that planning on using your current tyres for another twenty years is necessarily a wise idea as tyres do deteriorate with age. |
Edited by - Simon Johnston on 29/05/2012 22:16:48 |
|
|
|
Alain Pineau
France
13 Posts |
Posted - 29/05/2012 : 22:49:50
|
Thank you Simon for your reference.
I have bought my PA 3 years ago at an auction sale.
Unfortunately I only know that it has been fully restored in 1992 ( by a named "Velt" that has signed the car ) probably in NL.
This car has obviously almost not been drive before I get it.
So I guess that tires must be 20 years old, even if they look brand new as the whole car...
Should I change them ? |
|
|
|
Simon Johnston
United Kingdom
6186 Posts |
Posted - 29/05/2012 : 23:02:44
|
Alain,
I wouldn't presume to be an expert on this but it generally seems to be accepted that tyres over ten years old are potentially dangerous. The following is a quote for the web site of RoSPA (the Royal Society for the Prevention of Accidents - http://www.rospa.com/roadsafety/adviceandinformation/vehiclesafety/tyresafety/tyres-information.aspx#aging)
"Tyres that have been in storage should not be placed into use if they are over 6 years old, from their date of manufacture. When a tyre has been in use, the effects of aging are lessened to a degree, but such tyres should be replaced after 10 years."
I disposed of a set of unused Continental 4.00 x 19 last year that had been given to me about twenty years ago and never used. They looked fine but I wouldn't have risked using them. A new set of Blockleys cost £350 - good value I reckon. |
Edited by - Simon Johnston on 29/05/2012 23:03:22 |
|
|
|
Alain Pineau
France
13 Posts |
Posted - 30/05/2012 : 12:23:25
|
Thanks lot Simon for this a safe advice...
Reading your posts it seems that Blockleys are the best, any good adress to order them ?
|
|
|
|
etlanpa
United Kingdom
560 Posts |
Posted - 30/05/2012 : 12:30:43
|
Motor Wheel Services:
http://www.mwsint.com/ |
Edited by - etlanpa on 30/05/2012 12:31:08 |
|
|
|
Jerry Preston-Ladd
United Kingdom
20 Posts |
Posted - 30/05/2012 : 20:28:19
|
Alain,
Even if you decide (unwisely in my view) to retain the existing tyres, at least remove them and inspect the inside of the wheel rims. My PA was acquired in January and, as the tyres dated from 1983, I decided to junk them. The wheels looked fine on the outside but on two of them the inner rim lip was badly rusted and holed. The wheels too got junked. Expensive true but these are the bits that keep you out of the scenery.
Jerry
PA0417 |
|
|
|
Colin Butchers
United Kingdom
1487 Posts |
Posted - 31/05/2012 : 10:05:00
|
Alain,
For Blockley Tyres, see www.blockleytyre.com or phone them on 01386 701717
Best wishes,
Colin B. |
|
|
|
Topic |
|
Forum Locked
Topic Locked
