Inside Tyre Wear Issues (20'S) And Options For Replacement

[mburnz236]

hey guys, hoping (probably knowing) that somebody on here can help me out.

I run 20x8.5's on my ba2 turbo sedan and have had some pretty serious issues with inside tyre wear, specifically on the fronts. the wheels and tyres were brand new on the car when I bought them last august and have only done 14k, but all four will now need replacing. its work mentioning that the suspension is stock, not lowered or anything.

I've had 2 wheel alignments done about 2 months ago at a very reputable (well, highly advertised) place and they said its fine, yet I'm still getting horrible inside wear, I just noticed today that one of the rears (which I rotated front/back about 2 months ago) has a crack 3/4 the way arond the inside tyre wall, so its come right off.

if this because the tyres are 225/35/20 all round and are stretched to fit the rim?

could it just be because the tyres are the worst brand known to mankind? (Clear - tried to kill me several times in the wet so far)

or could there be an issue with my suspension set-up?

I know I will need new (and higher quality) tyres asap, but I want to clear this up before I do, so I dont wind up ruining them too.

also, in terms of sizes for replacement, I know 245/35 are good for the rears, but what can I fit up front? 235/35's or 235/30's or am I stuck with 225's?

thanks in advance

[Worm]

Fit fronts and rears 245/30/20... (nankang, neuton, achilles available and load rated)

Or get rear 245/30/20 (nankang, nueton or achilles) and fronts 225/35/20 (austyre)...

The fronts are fine with 245 as long as the profile is 30, not 35, as these are too tall and hit the upper control arm.

Never buy clear or triangle. They are death traps. Even though they say they are load rated, apparently it just has to be printed on the side... BUT THEY are not really load rated, hence the cracking in the side wall etc. I have nankangs on mine.

[mburnz236]

thanks mate, yeah looking at achilles atm as replacement brand, they tend to get some very good reviews for the price.

and on closer inspection seems 3 of my sidewalls are already cracked after not many k's and easy driving, next time I buy a car from a dealer I am going to look at tyre brand for sure, would never have bought clear's myself, I value my life much more than that.

but first I wanna sort out the inside wear issues.

[Adrian6T]

I have 20"x8.5" on the fronts and rum 255's. My car is lowered as well.

[Smoke them tyres]

Front inside tyre wear=

Sloppy front control arm bushes (particularly front lowers), but I would replace all of them.....no point in having tyres like that without having sharper response from polyurethane bushes. The wear is from 2 factors- toe out under braking load as the control arms try to move backward (thrust) and poor control of camber (radial) from said bushes. The wheel alignment is only a STATIC calibration. 1600+ kg hanging off rubber bushes with hard cornering does cause them to flex quite a bit.

Rear=

Lower control arm pivot eccentrics need less camber. The bushes in the cradle for the rear suspension arms are much better at controlling dynamic/actual loads than the front. Poly bushes at your leisure.

I would also (IMO) pull ALL of the shims out of the front upper control arms (if at std XR ride height) to gain about 1.5 degrees of neg camber with about 1.5mm toe in per side (std is about 0 degrees camber). These mods will sharpen up turn in, give more sustained lateral grip and improve wear across the whole tyre.

Edited 30/05/10 11:35 AM by Smoke them tyres

[mburnz236]

cheers for the detailed reply mate, sounds like you know exactly what your talking about. any idea how much that sort of work would set me back?

(oh and in response to other replies, I am know looking at running 245's all round with 35 rears and 30 fronts)

[Smoke them tyres]

Cheers....no problem at all.

Pat should be able to give you exact pricing on the bushes.

My estimate (?????) on the Fulcrum poly bushes would be around the $300 mark for the front lowers and $100 for the front uppers (all plus labour). They can remove the front shims when they do the upper control arms as the std Ford ones only have 2 holes in them necessitating the control arm to be removed to remove the shims. Fulcrum shims are slotted and only require the upper arm to be loosened to remove/fit them.

I wouldn't buy the Fulcrum upper control arm mount kit as these are identical to the std ones (except for the V8 ones with their only difference that the nuts to loosen the mounts are in the wheel well, not the engine bay......no problem on the sixes to get to the std nuts in the engine bay, so save a few bucks here and use the std Ford mounts). If you want to put some shims in it (which I wouldn't......unless to correct a difference side to side.....would to just buy a pack of the 1.5mm shims or check that the alignment place has the slotted shims they can fit). Many places give a different wheel alignment setting from left to right to deal with road camber, but in my experience, I have always had them equal side to side and have never had a problem. That theory of difference side to side to me is bunkum.

A good wheel alignment front and rear that I have had done cost $100 from of all places K Mart Tyre and Auto. I went to a well recommended place and got treated like crap so I went to K Mart as I had been told that the guys at that branch had a passion for what they do and the quality of their work and customer care I received proved it.

Edited 31/05/10 09:26 AM by Smoke them tyres

[senna_T]

As is generally the case, Smoke has seen this thread before I have! Sound advice above, also advice from real life experience

The Front Lower Control Arm bushes are generally the main cause of inside tyre wear on standard height vehicles because of the walk out effect under braking. The other issue is poor toe settings - this is something that can ruin the way your tyres wear, but also how the car drives. Smoke's pricing isn't too far off the mark, with the lower bushes (front and rear) coming in at $225 retail plus fitting and alignment. I'd also recommend changing the ball joints while you have the arms out, they are fairly cheap at around $30 each for a good quality unit.

The increased figures to counter road camber that Smoke refers to is generally the Caster settings, not camber (well it should be caster anyway). We generally set cars up with more caster on the left hand side to counter the road camber.

One piece of advice I will give when trying to find a good wheel alignment workshop is this - when you can, try and see what kind of alignment machine they have. Many workshops still use the old "Aim for the green light" style of machine, where the machine has a "preferred" setting and the operator keeps adjusting until he gets the green light. We use a live display unit that will show our operator the alignment settings as he adjusts. It allows us to control the setting from car to car depending on the available adjustments and condition of the vehicle and its tyres. Personally I would be much more confident seeing this machine in use at my workshop of choice as it shows the operator understands alignments and cares about the result.

If I can I'll get some pics and video of our machine so you can see the advantages.

Sorry for the long post!

[mburnz236]

thanks guys, really appreciate the effort you've put into the posts, I like to learn something new everyday ay.

seeing as I only live 20 mins from penrith and am always travelling down there from the mtns, might be worth a visit to wholesale then to get it checked out. might also have to save up a bit of coin first though too

[senna_T]

No probs mate, swing past and we can throw it up on the hoist for a free safety check.