wheel offset

[hall54]

what is the best offset on a mk1 running 14's x 6&7's?

[GTXTRA]

check with 'the autoad' - he was running some sweet watanabes on redroc earlier this year -

[Mike the Founder]

Have had this discussion many a time with folk with ' silly' offsets.
or should I say disagreement...
LOL
The geometry of mcpherson strut suspension for it to work properly is reliant on the correct offset for the wheels.
out of the guidlines and the wheel stand too far out meaning the suspension will not work properly, will be dangereous, torque steer, bump steer and be generally crap.

highest reccomended is as per the old style Mk1 wheels which are ET 45 I believe. This was on the old 6x13's I think? getting old memory fails me....
Lowest reccomended i guess would be et35ish. although I have known folk with 33 that said they were 'ok'
Standard VW ET was 38 ( again from memory) with 7 x 14's I think.
basically it is difficult to explain without a diagram.
draw an invisible line from the middle of the top mount down through the bottom ball joint and to the floor. At the point where the invisible line would touch the floor, you must not have more tyre outside this line than inside. simples. I actually have et43 7 x 15" on my VR6 and because of this can floor it and not even slightly fight with the steering wheel to stay in a straight line, no torque steer @ all.
hope that helps.
of course you get show cars with silly ofsets, but I really wouldnt wanna be driving them...

[The Autoad]

what he said ^^ ^^

the question was 'what is the best offset to run on a 6X14 wheel. the answer is that the 'best' offset to run is that of factory. Now, since Mk1's were never originally specified with a 14" wheel logic would dictate that you run a similar offet to the 14" wheel from a Mk2, as they are exactly the same track and suspension arrangement, the difference between the two cars being a larger body grafted onto the A1 chassis.

The wheels in the pic above are simply marvelous and stick to a more or less factory offset (from memory they are ET 35) -you can tell from the way that they sit in the arch. They handled very well, to echo Mike above, with no tramlining or tourque steer (the car above is running a 2.1 8 valve, no more heavier an engine than standard really).

I've been through the running of hooge wheels and very very low cars, and at the risk of sounding like a fart, i can honestly say that I think a Scirocco handles the best when sticking closely to a factory set up but with a mild lowering and lower struct brace. Of course, people out there are absolutely entitled to disagree with me and throw rotten fruit etc. Looks are a differnt matter, do you want to drive your car or pose in your car and polish it? both are equally valid in my opinion and are done for different reasons. The car above is a compromise between those extremes.

So, to return to the question, the best offset for a 14" wheel on a mk1. Try a set of 6x14" Avus wheels from the mk2 Scala but beware if you have the early Girling calipers on the front, as the Avus wheel will not clear these calipers, this may be the same for other wheels. Later 'VW11' floating calipers on the Mk1 pose no wheel fitment problems.

[PeteGLi]

If you do a search for posts by DougT, I think you will find a very informative post somewhere about wheel sizes and suspension geometry for the Mk 1.
I think it is on this forum, but I am too lazy to look for it this evening

[hall54]

cheers guys

[Mike the Founder]

a question came too my mind regarding this after looking at some of the old racing Mk1's which obviously had extended wheels given the extended arches being filled etc.
??
I guess there must have been more wheel on the outside of the invisible line than the inside with the racers - which in theory makes the geometry of the mcpherson strut system incorrect and give terrible handling, not something you are gonna have on a racer - these types of wheels would lend them selves more toward having a more old fashioned double wishbone system. So how did they achieve this setup on the old Mk1 racers??
Is it possible - that - given the geometry - i.e. drawing an invisible line down thru the bottom ball joint from the top mount, that with the use of metal adjustable top mounts, you could allow the use of wider wheels by adjusting these top mounts, so the shocker centre is offset towards the centre of the car, this would make the invisible line reach the ground further out - due to the angling of the shocker spring setup by the top mount centre being moved inwards. Obviously this would mean modification of the camber adjustment system so you didnt end up with the incorrect camber - thoughts anyone?

[Nate]

don't rally design do metal adjustable topmounts for the mk1 golf? this would presumably be for this exact reason?

[Mike the Founder]

yes mate i have em on me MK1 VR6.
however - my question is does anyone know if my theory works?

[MK140]

if you are talking about scrub radius than the answer is pretty straight forward > if you put on wheels with an et of say 25 instead of 35 you then need a wider wheel/tire to have the same scrub radius, if i remember right that would be a 205mm tire(camber might also play a role in this).atleast thats how i think it should be if not i stand corrected.

[Tee3]

surely there isnt a "best offset"?

It would depend on what you want from the car?

Ive had alsorts of offsets from zero to 40, and the best ride and steering feel was the high offsets. Best handling by far was the lower offsets. And the coolest looking were the zero offsets

If handling was my priority, I would fit ET15-25. Not based on numbers or factory (compromised) specification, but based on experience.

If i was fitting wheels purely for looks, I would go for ET0-10 on an 8" width and not worry about the handling

If i suddenly lost the use of the muscles in my upper arms and wrists and needed nice light steering... or our lass wanted a drive... i'd go for higher offsets

[Mike the Founder]

ahh... but there is a best offset.
As i explained above Mcpherson strut suspension is designed with specific geometry to make it work. If you go outside these limits and it simply doesn't work. You must have more or equal amount of tyre touching the ground inside where the invisible line drawn between the top mount and bottom ball joint touches the ground.

its simply down to maths...
so
by increasing the angle of the shocker by adjusting the top mount inwards, the point where the line touches the ground would be further out. So theory says that you could use a wider tyre and higher offset.
however the answer as too whether my theory is sound... seems unobtainable.... yet...

[Tee3]

simply doesnt work?

in what way?
I have ET8 and 12 on my mk1 Cabrio at the moment, and it definately works. It handles better than with my ET28 cups on it, feels firmer and tighter in the corners and inspires more confidence.
I would say it definately works...

The trade off is heavier steering and a little less return on the steering. Not to the point where its a problem.

[Mike the Founder]

no argument dude on what you find specifically works for you,,, for whatever reason.
I am simply quoting numerous discussions in car mags over the years as too how mcpherson strut suspension works geometry wise. That it was designed to work within certain tolerances and that outside these it simply does not dampen as it should. Without a diagram shwoing the geometry it is difficult too explain in text. also there are the torque steer and bump steer issues, too the point of it being dangerous. i have seen this on more than one vehicle not just VW, I specifically remember an old astra i had to diagnose that handled poop. It was simply down to too low an ET.
I suffer no torque steer at all on my MK1 Vr6. I have a high ET - 5 stud wheel. Tried a lower ET and the torque steer became apparent.
I am not thinking of altering my suspension. I simply had a curiosity as too my thoughts on the geometry of the Mcpherson setup....