Rethinking tyre pressures..perhaps I was wrong.
Discussion
Running on 18" wheels I searched out opinions on tyre pressures some 4-5 years ago and it seemed 24psi all 'round was a popular choice. This is what I chose for mine and it felt fine and so told others asking "What pressures" that I run at 24psi.
At the end of last year I started to have a slow loss of pressure on a front tyre (for a month) but regularly topped up the 3 or 4 psi it needed before using it and I did notice very slight cracking on the outer wall. Then, a 120 mile journey to see parents on the last weekend of Nov '10 saw the end of it. The tyre must have given up on the last couple of slow miles because I arrived with (guessing) 10psi and just a couple of minutes later it was flat.
At the tyre station I could see how bad the cracking was on the inside of both tyres, not just the flat one. Of course, I would replace both fronts together anyway and so had an emergency order for next day delivery of two Michelin PS2s so I could return for work.
The old front tyres were not premium brand (Marangoni Zetas) and were 4 years old but had plenty of tread depth on them. Perhaps running a pressure which was too low contributed to the rubber fatigue. With this thought, I now have 26psi rear and 28psi front (because the car's slightly heavier at the front now). Goodyear F1 asymmetric rear and Michelin Pilot Sport 2 front. Now, with the recent good weather I have been able to drive the car harder and the tyres feel good at this setting. But, that could be in part to changing the Marangonis (I felt they understeered) to a premium Michelin tyre.
My eventual conclusion is that perhaps 24psi is just too low for everyday use and one should try out higher pressures and perhaps, Marangoni don't use quality rubber compounds. I posted this for anyone who may have read my earlier quotes of 24psi.
Sorry this went a bit Ronnie Corbett in the big chair but thanks for sticking with it.
At the end of last year I started to have a slow loss of pressure on a front tyre (for a month) but regularly topped up the 3 or 4 psi it needed before using it and I did notice very slight cracking on the outer wall. Then, a 120 mile journey to see parents on the last weekend of Nov '10 saw the end of it. The tyre must have given up on the last couple of slow miles because I arrived with (guessing) 10psi and just a couple of minutes later it was flat.
At the tyre station I could see how bad the cracking was on the inside of both tyres, not just the flat one. Of course, I would replace both fronts together anyway and so had an emergency order for next day delivery of two Michelin PS2s so I could return for work.
The old front tyres were not premium brand (Marangoni Zetas) and were 4 years old but had plenty of tread depth on them. Perhaps running a pressure which was too low contributed to the rubber fatigue. With this thought, I now have 26psi rear and 28psi front (because the car's slightly heavier at the front now). Goodyear F1 asymmetric rear and Michelin Pilot Sport 2 front. Now, with the recent good weather I have been able to drive the car harder and the tyres feel good at this setting. But, that could be in part to changing the Marangonis (I felt they understeered) to a premium Michelin tyre.
My eventual conclusion is that perhaps 24psi is just too low for everyday use and one should try out higher pressures and perhaps, Marangoni don't use quality rubber compounds. I posted this for anyone who may have read my earlier quotes of 24psi.
Sorry this went a bit Ronnie Corbett in the big chair but thanks for sticking with it.
I had my first long drive in the my Cerb yesterday after 4 months of ownership and broke my first 100 miles and in the dry. I to have just fitted Goodyear eagle f1 aysmetrics , i used to run the v-pattern on my old chim.
Wow, i love these even more than the old F1's and they were good. I went to my private road/land yesterday to get a feel for the car in some open space some skids and slides and the level of grip from these tyres or just the car really really suprised me. The chim would break traction far easier than the cerb and it was only a 225bhp 4L. I tried some fast take offs and trying to do some take off wheels spins and it was not for having it just savage acceleration. I thought about changing to 18" spider but the car rides so well even over the bad roads we have so i will be sticking with them it is night and day for ride comfort from the chim really happy with it.
I like it
Wow, i love these even more than the old F1's and they were good. I went to my private road/land yesterday to get a feel for the car in some open space some skids and slides and the level of grip from these tyres or just the car really really suprised me. The chim would break traction far easier than the cerb and it was only a 225bhp 4L. I tried some fast take offs and trying to do some take off wheels spins and it was not for having it just savage acceleration. I thought about changing to 18" spider but the car rides so well even over the bad roads we have so i will be sticking with them it is night and day for ride comfort from the chim really happy with it.
I like it
Edited by scotty_d on Sunday 20th March 20:23
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