Wheel spacer question

[Gssplaya]

if you have an offset 42 and 18x7.5 wheel, whats the new offset when adding a 3mm spacer? whats the max. safe spacer thickness that could be used in our cars ?

[zedy1]

why do you want to put spacers on

[Gssplaya]

well its a secret for now :) so any answers to my question?

[zedy1]

cant help u wth that mate

[Nick Mann]

I am not an expert, but I understood the offset to be a measure of the whereabouts of the mounting face of the wheel. The way I have understood it, increasing the offset but staying with the same width wheel moves the wheels towards the edge of the car. Therefore I would guess that a 3mm spacer would effectively change your offset from 42 to 45. This will have some kind of effect on handling and ride. It also puts extra strain on suspension and steering parts. As to the max possible on the car, assuming you extend the wheelarches to cover the protuding wheels, anything you want, providing the suspension and steering components can take it.

If your question is what can the car take before parts start snapping, I haven't the foggiest!!!

[Nick VR4]

Adding to Nick's post
This will put stress on the wheel nuts and lugs too so you may have to get extended lugs fitted ????

[calum]

39mm.


Calum

[zedy1]

and a pain in the arse to change the wheels

[Spirit]

Nice little diagram for all the techies:

http://www.comp.co.uk/pics/diagram_01_new.gif

[calum]

Nice little diagram. Just one thing - PCD is Pitch Circle Diameter, not Centre.

To explain my earlier answer, using a 3mm spacer is like adding 3mm of metal onto the back of the mounting face. This would reduce the distance between the centre line and the mounting face - in effect, 'reducing' the offset.

Calum

[calum]

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[Gssplaya]

excellent :) thanks!

[Nick Mann]

So reducing the offset moves the wheels towards the edge of the car. Exactly the opposite of what I thought before!

:headsc:

What a donut! :D

[calum]

Originally posted by Nick Mann
So reducing the offset moves the wheels towards the edge of the car. Exactly the opposite of what I thought before!

:headsc:

What a donut! :D

Not necessarily - depends if we're talking about positive or negative offset. Positive is when the mounting face is towards the outside face of the wheel, and negative when it is towards the inside face.

However, you don't find many cars with negative offset wheels nowadays.

Calum

[Nick Mann]

Surely an increased offset is adding to the current offset. Even if you are in negatives, adding adds! INSERT INTO post VALUES (Just 'cause the number is closer to zero doesn't mean that it's less.)

I just had it back to front, or arse over tit!

:D

[calum]

I'll shutup now - I've even confused myself!

You've got it sussed now, though!

Calum