Help please with wheel offset for CSR 13 x 9" and 13 x 7"

[tommy turtle]

Hi,

I currently have the 13" caterham superlight wheels on my Tiger in 8" on the back and 6" on the front but I am looking to buy the Caterham CSR 13" wheels in 9" rear and 7" front but would like a definite answer on the offset of these wheels. Does anyone know these offsets please. Any help appreciated.

Thanks

Tom

[nicemd]

7 x 13 et40 - 139mm backspace
9 x 13 et30 - 158mm backspace

source: http://www.blatchat.com/t.asp?id=139007

[mickrick]

I've been doing sums for a 9" split rim on the rear.
I want to use an MB wheel, and I believe you don't want to go more than 5 1/2 inch back space. That equates to an offset of 14.7mm.
Don't forget, a 9" rim is actauly more like 10" as you have a 1/2 inch bead either side.
Mike Barnby tells me you don't want to go larger than a 6" inner rim, as you'll start hitting things.
So, for a 9" MB split, you'll need a 6" inner, and a 3" outer with 14.7mm offset.

I appreciate you want CSR wheels, but the offset will be the same.

Try drawing it out full size as a line on a piece of A4.

You will have the same backspace on the front with CSR wing stays. 5 1/2 inch.

If you keep the same 5 1/2 inch backspace, then you can use a spare front wheel on the rear as well. If you carry one that is.

Hope that doesn't confuse you even more!

ETA, I'm only going on what Mike told me over the telephone regarding the rears, as I'm still waiting for CC to get driveshafts in stock, so haven't got my hubs on to check myself. But I'm very shure about the front backspace.
However, I think Mike Barnby should know what he's talking about!

Edited by mickrick on Friday 17th June 21:53

[tommy turtle]

Thanks for the info chaps. Appreciated.

Tommy

[fastcarl]

before you spend any coinage with MB you may like to look here,

www.force-racing.co.uk

[Flatfloor]

The Force Racing wheels to suit Caterham calipers and offsets are only available via 7 Tips.

When I enquired they had completed a number of sets and have had to cleverly redesign the centre to fit a 7.

I have seen these wheels at both Autosport and Stonleigh and every time I pick them up I just can not believe how light they are. Just a shame my pocket is not heavy enough to afford themhttp://www.pistonheads.com/xforums/imgs/8.gif

[mickrick]

The Force rims look very nice, but so far, MB wheels are the only ones with a 13" rim that will package my brake setup.
MB's rims have a larger insid dia. in the caliper area as they're used by many historic F1 cars.

[fastcarl]

i woild be very surprise dif the MB spinnnigs ar any different to the Force spinnings.

[mickrick]

They'd have to clear a caliper radius of 156.5 and the centres would have to clear a calliper protusion of 15mm.
If you have some CAD drawings of the rim profile, I'd be happy to look at them.
Feel free to PM me.

Cheers,
Mick.