Hey all...

Haven't seen a thread on rim vs tire sizing.

Reason I ask is to see if anyone has a table of suggested rim widths for various tire sizes.

Currently my 58 has 15x5's all round running 135R15's on the front and 205/60 15's on the rear. In my opinion it looks cool as - but handles like a bag of shit from tire flex in the rear end.

Interested in hearing people's experiences on the topic.

Thanks.

Try going back to a 195/50/15 on the rear if you want less tyre flex. running 135 on the front isn't the optimal if you are going to throw it around. 60 series profile on the 135??

That tyre size should be fine, even if it is at the top limit.
Prob need more pressure.
Try CT in the circuit racing section,
He knows all about tyres.

205/60 should be running around 36psi for street use. If you want to do some more "spirited driving" then bump em up to 40 psi.

Ok - I'm running 40psi - up from 36psi.

I'm not particularly talking spiritied driving either - just normal

The rear end wonders around a fair amount. There is obvious negative camber on the rear due to it being lowered but a wheel aligner on Monday suggested there is no toe in on the rear to worry about.

With the car sitting there and pushing from the side you can get reasonable side to side wobble up...

I'll try CT.

Thanks guys.

my ex just went thru sumthing like this.......tyre service fitted one size larger tyre to her rims, which turned out to be too big for the width (195).

contrary to what i imagined, the tread surface actually didn't touch ground for a very large area in the middle of the tyre, so it rode effectively on two hills on the outer edges of the tyres.

chewed up tyres in half the kms, the "valley" in the middle where the tread was almost as good as the day they were fitted was clearly visible and definately measurable in mm if not cm's!!!!..........we thought the tyres had somehow warped, gone off or hardened via massive heat, they looked that bad

to drive it was like having four tiny contact patches on the front wheels instead of two nice flat ones, and was absolutely scarey, tracking erratically.



anyways..............

there will be a tyre fitment guide some where on the net, they are usually on the tyre type brochures in the waiting rooms at tyre centers.

been there done that with the over size on the beetle and hear what your saying, widest rimm with narrowest fitted tyre gives best feel and response time to direction change.

for me 185/195 on sixes, 205's on sevens

Thanks again guys.

From what I've found the rears should really only be 165's for the 5" rim.

As for rear toe in - gotta find someone I can trust to check it again.... Maybe I need to raise the car - it is a daily after all...

Hi

You need to go up in tyre size on the front and down on the rear. 135 will fit those rims OK but would be illegal for use in NSW on that rim size, I'm not sure about the NT.

From the NSW RTA website "Tyres: The tyre and rim industry sets standards for the correct combinations of wheels and tyres. Individual tyre manufacturers publish this information as tyre selection charts. If you are in doubt as to which tyres are acceptable alternatives for your car, ask your tyre dealer to check these charts for you."

I'm sure that a 5 inch rim is not the recommended rim size for a 135 tyre.

I'm not fan of high tyre pressures on correctly sized tyres. On all of my VWs with performance tyres I run close to factory tyre pressures, ie 20 psi in the front and 25 psi in the rear, I would bump it up a few psi for rack use.

Steve

If I run factory pressures in the tyres on my kombi it would handle like a bag of crap. I'm running 225/50/15 on the front (36psi) and 225/60/15 on the rear(38psi). If my front tyre pressures drop lower than 30psi the steering is real heavy when slow manouvering. Gives the arms a good workout though!!

Reuben didn't read you were running 5" all round. My bad. yeah on 5" rim no bigger than 185 and that is prolly on the limit.

Thanks again guys

Gday,

For 5 inch rims i would suggest a 185/50or 55 series tyre with around 24psi in the front

For the rear maybe no larger than 195/50 or 55 tyre with around 26psi .

The rear end wobble is from as you suggested to much tyre side wall flex and the large inflation of 40psi would only exagerate the problem,as with that much pressure your running on the middle third of the tyre only.

Cheers Col

when mucking about with my old 68 standard rims 165/ 65 100 wear points, lowerd with eccentric adjusters whiteline race bar kyb short gas shocks good old koni reds inthe rear and camber compensator, I had to change tyre pressure constantly for wet and dry conditions down to 18psi inthe front 28 rear wet 26 psi front 32 rear dry. when i put my cookie cutters on after rego tyre pressure became less of an issue was runnen i think about 26 and 32! By the way set up was 2deg neg front 2mm toe in front, cant remember the castor but had 2 sets of castor shims in, rear was still a swinger but had 1mm toe in with the resting weight at 2 deg neg camber, had wagon rear bars. Tyre v rim size plays a very imortant roll on the way your setup reacts, to small a rim and the roll centre gets higher so has a tendency to "fall off the contact" to wide a rim and you get sidewall flex that promotes a very uneasy transition like when goin thru a round about it will get a bit of whip which loads up and then lets go all of a sudden. however all things to all men, its what works for you! by far the best way of sorting out what works for you is doin track days and reub your other car is shit hot and shiney

Reub ,What you got is fine in tyre size , for the look ! you want ! It will never handle like a race car , will allways push on corners and front tyres will follow every groove in road or lanes .Driving a lowered bug is a very different animal mate .Rear rims a little narrow there (brm's are 5 1/2 fine on Rods ,6inch best) maybe step back to 185's.
On front have you got drop spindle on yet ? Front /just a little toe-in 2mm or straight , 1set off caster shims , shocks - standed or a short shock - little firm - oil , 135's at 26psi (make sure of / kingpins -linkpins are fine (linkpin shims done ), steering box is good ,all balljoints , front trailing arms not warn .
On back / 2mm toe-in , 50/50 firm shock oil or gas , spring plate bush's are good ,tyre's 32>36psi ,Rear caster no biggy (1 spline drop ), bump stops -hard on stop (early bus )
My beige bug was like this for years .The condition of front end makes a big big different's on what the rear feels like .

The front end in my 58 has been narrowed 3" and fully reco's (i.e. new king pins/bushes, new link pins/bushes, bearings etc), has dropped spindles with flipped late model tie rod ends at the spindle, steering box appears to be ok (bought off the forum when 6 months old), new wheel bearings etc an custom discs - so essentially the front end track is only slightly narrowere then stock.

Shocks all round are Monroe GT Gas - bought new - and potentially too hard all round.

I've not checked the rear end drop - is as was when I bought the car 18 months ago. Have not checked rear bushes.

As a trial I've just got home from a spin with the original steel wheels on the rear running 165R15's. The car drove marginally better but moved about the same way.

I'm not expecting the car to drive like a race car, just to drive in a pradictable/confortable way

I think the narrow front end probably causes the oversteer.

The narrower front tyres and different track probably causes tramlining and wandering.

Have you had all 4 wheels aligned?

The optimal rim fitment for a 135/80R15 is 3.5 inches. But up to 4.5 wide is allowable. Anything wider is not recommended.

The optimal rim fitment for a 205/60R15 is 6.0 but 5.5 to 7.5 is allowable.

You should run the same tyre front and rear. If not run a similar tyre ie directional or asymmetrical.

The 60 series profile should be nice and firm. But the 80 series won't be. So that might be creating a miss-match.

As for tyre pressures I start at 31 on all corners at the race track to get the tyres in their 33 - 37 psi hot operating window as soon as possible.

Factory tyre pressures are normally comfort oriented. So another 2 psi benefits handling and tyre wear, usually.

On the street I run 24 front and 28 rear. Sometimes I've dropped the pressures to 22 and 26 for extra comfort and noticed no adverse effects. The track on my car is identical front and rear on race tyres, which I found is important.

On the street tyres the rims are 6.0 front and 7.0 rear which widens the rear track and makes the car tend to oversteer. The tyre size is nice and cal-look being 175/55R16 front and 205/50R16 rear. This mismatch of track and tyre width causes a bit of tramlining on rutted roads, but the handling is still good due to the quality and newness of the tyres.

I hope that waffle helps in a roundabout kind of way.

CT

Thanks again all.

Appears there may also be something else up - like rear toe in probs as Dave suggested - that the aligner most likely did not check for me as asked....

I think a raise of the car initially is on order

It is cool to 'have the look' but nobody wants to be chasing there car when driving it - takes the fun out of it all...

Also, here is a web link another forum member posted...

http://www.rims-n-tires.com/rt_specs.jsp

just deal with it rub's.
give it more power and steer with the rear.works for me.lol.
ct hit it on the button,but before going nuts with all the info you have been given,all the wheels should be pionting in the wright way ,see how it feels,then go nuts.
been realy slack,i have been looking at your flanges now for a few weeks saying fuck i forgot to send them again.sorry dude.will send them on monday.
cya

I'm now running 165 80 15s on front and rear

front lowered

20 - 30 PSI front rear

and My car being an IRS rear end

really sticks to the road..

Very pleased with it...

I will be going to 205 70 15 on the rear again... on day

Lee