Board logo

Tyre wear at front - Why ????
sooty - 28/7/11 at 09:52 PM

Had my front suspension settings (Camber, Castor and Tracking) checked a few months ago and all was OK.

But why are the tyres on the L/F wearing on the inside and R/F wearing on the outside very edges, wanting them to be changed before the main tread is anywhere near the legal min..

If it was the other way round I could understand this being due to road camber etc.

Any clues ??????

Thanks

[Edited on 28/7/11 by sooty]

austin man - 28/7/11 at 09:58 PM

may help to post what car you have

sooty - 28/7/11 at 10:16 PM

Sorry,

To be Honest its not my Striker, but my main car a STi Scoobie with fully adjustable front end including spring heights.

thanks

austin man - 28/7/11 at 10:24 PM

if you have opposite wear ie inside on one wheel and outside on the other I would think the camber is wrong. It seem as though you have negative on one wheel and positrive on the other

Doctor Derek Doctors - 29/7/11 at 09:31 AM

quote:
Originally posted by sooty

STi Scoobie with fully adjustable front end including spring heights.


How well was it set-up? It could be any number of things if it wasn't set-up correctly when the adjustable front end was added.

Camber issues seem to be the most likely though, or perhaps the car is 'crabbing'?

The again have you double checked the wheels and tyres? If you have outside/inside tyres that are on incorrectly or different offset wheels side-side then this could cause an issue? Does an STI Subaru have different wheel offset/size front-rear? Perhaps you have a front and rear wheel mixed up from when tyres were fittted of modifications made.

When I was at a Porsche Race team we had a customers road car that we did some work on, we could never get the thing to drive straight though and the handling was wierd, we checked it on manual and laser gauges, corner weights and the string until we were blue in the face.
After almost giving up we put the wheels from another car on and it solved the issue. So we measued the circumfrences of the tyres and although both rear tyres were brand new P-Zeros of the same size we found a 15mm difference in the circumfrence of the rear tyres, wierdly Pirelli took them back without argument and never mentioned it again.

hughpinder - 29/7/11 at 01:43 PM

I had a similar wear thing on a rover 820 I had - the handling wasn't quite right, but it was only after the (new) spare wore out after in about 1/5 of the normal time that I found out it was a 195/65R14 and the other 4were 195/55/R15. Everyone at work laughed themselves silly, but two people subsequently checked theirs and found the same problem - wheels had been upgraded when the car was first sold, but the full sized spare hadn't.

You can get wear on one edge of a tyre if the camber is wrong, springs worn or damping wrong do it too. I guess if one of your springs has the wrong length, poundage or adjustable mount wrongly set , then this could happen.

Regards
Hugh

britishtrident - 29/7/11 at 03:21 PM

Sounds like camber but the I would check for a broken or sagging spirng first ---- check all 4 springs ,
Then on a level floor check the car is sitting level (transversly) in the condition it is normally driven --- ie driver's weight in the car and only then set the camber and toe with the drivers weight in the car.

sooty - 29/7/11 at 08:42 PM

Thanks for the replies

The alloys are all same size as for offsets, all tyres are same size although fronts are Falken's and rears Toyo's and all are right directions on rims.

Having new Falkens fitted to front tomorrow and tracking checked again.

During next week going for a 4 wheel laser and suspension check. If all is OK, I will then show the tyres and await comments as why the tyre wear.

My only problem maybe where the 4 corner weights maybe correct, but as it's so stiff its not knowing if the adjustable damper setting/ratings are the same one side to the other.

Will keep posted the outcome later in the week.

thanks

phelpsa - 29/7/11 at 08:44 PM

The damper issue is quite easily solved but will require dismantling it and having them dyno'd.

Mark Allanson - 29/7/11 at 08:52 PM

If the Geo was set up statically, then the problem must be in the dynamics. The camber change on bump and droop must be out and the only way that can happen is if the subframe has been shunted laterally due to impact, and then adjusted out. That would give exactly the symptoms you describe asymetrical suspension!