Morning all! Fitted my KYB AGX adjustable shocks and Ebach springs yesterday but have a slight problem with my Rear Tyres grinding on the arche's when going over bumps...

It's fine when driving along normally but if i go over a bump in the road you can hear it rubbing the arch as the wheel is trying to go up there..

 

Now my tyres are 285/35/18 on a 10j rim and are getting on a bit so thinking of maybe changing them to 285/30/18 so they are not as tall and may just help when going over bumps.

Was trying to find 275/30/18 on the net but that size doesn't exist and 265/35/18 on a 10j rim the tyres are too stretched on and the wheel rim's have no protection!

At the moment the tyres are quiet wide and just slightly stick out from the rear arches a fraction by a few mm.

 

Another option maybe would be adjustable upper rear arms but cause of the chunky tyres don't know if this would help!

 

Im currently running the rear KYB AGX on 7 and over big bumps it does grind, they only go up to 8... Had them on 5 originally but they would grind on the arche's more!

 

If anyone could help me out please here that would be much appreciated!! Thanks!

Yeah that's what im thinking of doing but also seeing as I need new rear tyres im gonna go down to a 30 profile rather the 35 they are on now... Might help a little bit hopefully!

When u get a thinner tyre the profile will change too.

 

See a 225 40 18 and a 255 35 18 are around the same.

 

If u got a 225 35 18 the profile would be smaller then the 35 on the rear.

 

The profile is a percentage.

 

Maybe u know this all ready and I read your post wrong lol.

When u get a thinner tyre the profile will change too.

 

See a 225 40 18 and a 255 35 18 are around the same.

 

If u got a 225 35 18 the profile would be smaller then the 35 on the rear.

 

The profile is a percentage.

 

Maybe u know this all ready and I read your post wrong lol.

 

Yeah I knew that hence the reason for going smaller on the rolling radius! Going 285/30/18 is only 1mm difference from the standard 245/45/16 on the radius... Thanks anyway Terry!

Ok if someone could advise me what tyre size would be best to do as a temporary solution till I can get my arche's rolled that would be much appreciated!

 

Currently 285/35/18 so do I go:

285/30/18 so less height or

275/35/18 so 10mm less width

 

Please help someone!!

Without rolling you will not have an issue with 265's but reading back you don't want a little stretch which in my opinion is not unattractive.

 

You need to go to a part worn place and talk to them, pay and fit some 275's with an option to swap them for the 265's or vice versa.

 

As long as you pay a fiver for each swapping about they wont be bothered.

 

They will also have some new tyres also once you've decided :cool3:.

That tyre is enormous, fit normal size ones and the problem will go away.

That tyre is enormous, fit normal size ones and the problem will go away.

 

Um nope? Pretty average choice of width for aftermarkets. The wheels offset is wrong so it doesn t5 rise into the arch it hangs out the arch and catches.

Um nope? Pretty average choice of width for aftermarkets. The wheels offset is wrong so it doesn t5 rise into the arch it hangs out the arch and catches.

 

So can I adjust the offset with the standard upper arm's or do I need to get new ones??? Also would getting Coil spring spacers, boosters, lifters or what ever you call them help to raise the ride height a little? Thinking I don't need much of a raise as before the Ebach lower springs and KYB shocks we're fitted the clearance with these wheels and tyres was fine, even going over bumps!

You wont be able to change the offset that way without runnning excessive negative camber, unless your prepared to strecth the tyres to get a better clearance or roll and pull the arch they wont fit without rubbing. Even with some strecth you will syill most likley need to roll the arch. The only reason they didnt rub before is at the higher ride height the travel was suffient for them not to touch.

The only reason they didnt rub before is at the higher ride height the travel was suffient for them not to touch.

 

Thanks for you help on this dude, really appreciate it.. Thinking im gonna roll the arches and get some of these to go in between the coils either side....

 

http://www.larkspeed.com/index.pl?c=GRAYSPRNGB&s=category

Have you considered just replacing the wheels for a set with a more forgiving offset?

Have you considered just replacing the wheels for a set with a more forgiving offset?

No, it's not an option really! Buying new wheels is just way to expensive!! Would rather just stick the old springs back on if the coil spring lifter booster thing doen't help. It only grinds over the bigger bumps, smaller ones and dips in the road it won't grind. Only need another 15 20mm clearance and it'll be ok so not much of a raise.

Why not ask a local engineering firm if they can mill the inner face of the wheels down a couple of mill then you get to keep the same wheels and size tyres, yet they sit in a couple of mill further.

Not a good idea as you will weaken the wheel where the nuts tighten to the hub.

 

Paul

Hey Jon. Why are running 285s on there mate? I'd certainly go down to 265s at least judging by the photos. That would probably fix the problem without needed to do anything more drastic. (sorry if it's already been discussed on the thread?)

Just read back the bit about saving your alloys and your sizes etc. Thats those Redruth granite curb-stones for you Jon :D I honestly think you'd be much better with 265 maximum, it must be a really wooly drive with so much extra rubber on the back? 265 will make it drive a lot more precise. I run 235 on 10J on the track car.

Hi Dave! Been running 285's for years now! Just the drop that was causing the issue but fixed it now by dropping a profile size so now im 285/30/18 and running the KYB AGX on 4 at the back now so not too stiff and gives good damping for our Cornish roads!! Been over big bumps as well now and now rubbing, car also pulls a bit better cause with the lower profile it's geared it down a bit!

Nice one, glad you're sorted mate :) I'm looking forward to some more Penwith sometime soon.

Nice one, glad you're sorted mate :) I'm looking forward to some more Penwith sometime soon.

 

I reckon secretly someone wants another zed.....but can't bring himself to admit it :whistling:

Haha probably still the best all round road car I ever had :) My current road car is a 4.5l v8 Bimmer which is pretty awesome, but I can't take the roof off so the Zed still gets the No1 spot!