Caterham wheel offset?

[Kitcat]

This is an adjunct to my 13" wheel/tire thread. I am trying to find a 13" that fits my '03 Superlight. I have the bolt pattern as 4x108 and the center bore as 55 mm (2.16") and, obviously, the wheel size as 13'' (width likely 6-7"). Anyone know the offset? Tire Rack needs that to search their inventory.

 

My Prisoner wheels had 21 mm offset on my original Caterham. The Mog site (only place that I can easily find that sells Caterham-specific wheels) lists various offsets from 21 for a 7x13 wheel, 9 for a 8x13 and 15 for a 9.5x13. Since the Prisoner wheels are 21, and the 13x7 are 21, seems like that is a safe offset # to use?

Edited July 27, 2013 by Kitcat

[MichaelD]

Mike,

 

https://www.rsracing.com/tech-wheel.html

 

Explains how to calculate the back space your car requires. I will measure my CR500 wheels tomorrow and get back to you.

[JohnCh]

Here are the specs for the Caterham 13" wheels that the US distributor sent me a few years ago:

 

13"x6" (front)

.96875" offset (24.6mm positive offset)

4.375" backspacing

 

13"x8" (rear)

1.53125" offset (38.9mm positive offset)

5.9375" backspacing

 

Also, my prior research shows the bore center is 63.3mm, not 55mm. Might want to measure what's on your car now to confirm.

 

-John

[MichaelD]

Mike,

 

2000 Superlights came with CR500 Mike Barnby 3 pc, 13 x 8 R and 13 x 7 F. http://www.mb-racingwheels.com/contact.htm

 

The backspace on my Kodiak 13 x 10s is 4.5 in F&R. That is fine with a stiff walled Hoosier but the softer Avons require 4.25 in the rear. I think that anything greater than 4.5 will result in rear inside tire rub.

 

You can run any backspace that is less than 4.25. The backspace will determine the offset. Less backspace will move the tire to a wider stance. Measure as described here: https://www.rsracing.com/tech-wheel.html

 

You will also want to provide them with the distance from the wheel/hub center to the outside and inside edges of your brake calipers.

 

w

Edited July 28, 2013 by MichaelD