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Vibration

Just bought a 2001 93 lpt convertible. At 30mph there is a very noticeable vibration which seems to come from the back wheels, as you go over 30mph the vibration stops. When I test drove the car this didn't happen. Since then, the garage changed the discs all round and put on 4 new tyres. The original back tyres 225/45/17 were slightly different from the front

215/45/17 but the new ones are all 215/45/17. Someone told me that the back tyres need to be different - is this correct? I intend to take the car back to the garage next week so any advice would be greatly appreciated.

Mark

Reply to
Mark James
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It may be an issue due to the pressure inside the rear tires. If I remember well, they theoretically must be at 2.0 Bar, but many people (me included) advises to inflate all tires up to 2.3 bar.

hope this helped

BR

Pascal

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Reply to
Pascal B.

Do you mean 2.0 to 2.3 atmospheres. Seems very low.

Malcolm

Reply to
Malcolm William Mason

1 bar == 1 atmosphere == 15psi. So 2.0 bar = 30psi, 2.3 bar = 35psi.

By the way Malcolm, is there any chance you could remove my email address from your "Trivial" list? I'm not sure how it got there in the first place.

Reply to
Grunff

What therory would that be?

Even 2.3 is very low for a low profile tyre/tire like 225/45/17. I have

3.2 bar in my summer tyres/tires with the same dimension, but normal range for this dimension would be something like 2.8 to 3.2 bar.
Reply to
Goran Larsson

Tyre fitters just look up the tyre pressures in a book and inflate accordingly, that doesn't take account of special low profile wheel/tyre options. I got 27 psi in four new 205/55/16 for my 9000, it should have been 34 psi. You would think tyre fitters know their business, but who cares...

Reply to
Johannes H Andersen

What theory ?? very easy,!! the more you inflate the larger is your tire perimeter, so the frequency of vibration triggered while rotating is different and it may be enough to disable the dicommodious vibration.

Me, myself and I apologize for the mistake in my original reply , I wanted to say 3.0 instead of 2.0, and 3.3 instead of 2.3...sorry...

Pascal B.

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Reply to
Pascal B.

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