Wheels?

[deezee]

Originally Posted by Big Vern

At 7 inch wide you'll need an ET of 41 or maybe even 44 to get the correct offset ie centre line of the wheel rim in the same location as the 'book'.
I have a nice set of mk5 RS 2000 alloys for sale, which are 6x 15 et41, and would certainly suit.

HTH BV

Why would you need the wheel to sit 3mm closer to the car? The offset is a measurement to the centre of the wheel and is irrespective to the actual width of the wheel, be it 7 inches wide or 6 inches.

[jps]

Originally Posted by deezee

Why would you need the wheel to sit 3mm closer to the car? The offset is a measurement to the centre of the wheel and is irrespective to the actual width of the wheel, be it 7 inches wide or 6 inches.

Surely offset increases or decreases as width of the wheel changes, assuming that the 'outside' end of the wheel stays the same - otherwise offset is meaningless?

E.g. if a wheel is 100mm wide and the offset is 40mm it means the 'spoked bit' of the wheel is 10mm thick (i.e. the mounting face is 10mm inside the wheel - but on the outside edge). If the same wheel is 200mm wide and the 'spoked bit' of the wheel is 10mm thick then the offset would need to be 90mm??

*numbers made up for illustrative purposes...

[voucht]

Originally Posted by jps

Surely offset increases or decreases as width of the wheel changes

Sorry JPS, but I think you are mistaken, and I disagree with that.
The offset of a wheel is given by a manufacturer by the "ET".
ET is is the distance between the middle longitudinal plan of the wheel and the plan of the wheel's face against the car's hub.

ETWheel.jpg

You can have a 3'' wide wheel or a 9'' with an ET38, the offset will still be the same. Just the wheel will be wider, so wider outward AND inward

Hope I'm clear in my explanations

[jps]

Originally Posted by voucht

Sorry JPS, but I think you are mistaken, and I disagree with that.
The offset of a wheel is given by a manufacturer by the "ET".
ET is is the distance between the middle longitudinal plan of the wheel and the plan of the wheel's face against the car's hub.

Attachment 1585

You can have a 3'' wide wheel or a 9'' with an ET38, the offset will still be the same. Just the wheel will be wider, so wider outward AND inward

Hope I'm clear in my explanations

Ah ha!!!!! No idea why I was being so thick!!!

I was thinking that the offset was measured TO the centreline, rather than FROM the centreline. I was also making the assumption that wheels were made wider by just adding width to 'the inside' rather than widening inward and outward...

Silly me!

[Not Anumber]

I want to get hold of a spare wheel for long journeys as I dont trust the spray and pray cans.
Applying the knowledge above, do I need to look out for a Sierra (or other rwd Ford) steel wheel or could i get away with using something from a Focus or Mondeo ?

[alga]

Any 4-hole Ford wheel should do, including ones from Escorts, Focuses and early Mondeos. From 2001 Mondeo switched to 5-lug pattern.

[Not Anumber]

Thanks, no excuse for me not to pick one up and start making that spare wheel bracket when the snow clears.

Appologies for highjacking the thread.