View Full Version : Wheel Offset

03-07-03, 09:03 PM
As I do not have a grand to spend on Halibrands, I have been looking around for decent looking wheels to fit onto my Sumo. I think I have at last found what I am looking for, and at a pretty good price too(Raceways of Donington, advertised in July's Kitcar Magazine). However, the wheels I like are only done in 7x15 with -10 or +15mm offset and 8x15 with -20mm offset (for a Sierra based model). Now Pilgrim's latest manual states that the 7x15 should have -10mm and the 8x15 +5mm. This contradicts their earlier Mk3 manual that states 7x15 should be -20mm and 8x15 should be -22mm. For the life of me I can not see why though; the donor car has not changed and the Sumo dimensions are also the same. Also, my understanding of offset is that the more negative it is, the greater the ratio of dish (and the Cobra usually has a large dish on the rear wheels). So, am I getting confused or what? I even contacted Pilgrim, who were even less sure than I was (now thats crazy). Can anyone out there explain what wheels I can fit on my Sumo rather than pay Pilgrims prices for Halibrands. Can anyone advise me of somewhere else where I might find decent wheels (I know that I will not be able to match the looks of Halibrands; but, in time maybe).

Thats enough from mee, you are all probably asleep by now.


03-07-03, 09:33 PM
Try revolution road alloys. They keep 15" wheels especially for the Sumo.

Sorry don't have the number to hand

04-07-03, 07:40 AM
Interesting questions. you should be also aware that I have spoken to a number of SUMO builders who have failed SVA when using Pilgrims wheels because the front wheel rims are outside the wheel arch. Which suggest that the wheel width or off-set is wrong.

I raised this with Tony who said that he may need to look at a different off set if this becomes a regular problem.

I too am looking for suitable low cost wheels but more importantly a wheel that will fit inside the wheel arch.


' and it was going oh so well '

04-07-03, 11:24 PM
I bought these Revolution Wheels, around 80 each, I think -

When I finally found the UK company they were very helpful, and knew which wheels were for which mark of Sumo - of course I haven't actually fitted them yet, owing to problems sourcing tyres...

Here's the address-

012 9385 1776

04-07-03, 11:28 PM
Just found the earlier thread

Two 7x15, two 8x15, nuts and caps - 455

See http://www.cobraclub.com/crcforum/dcboard.php?az=show_topic&forum=7&topic_id=9765&mode=full

07-07-03, 11:07 PM
Thanks for all the replies.

I now have the choice of several wheel options out there, although I am still very keen to use the ones mentioned in my first post (check them out they loko really nice for the price, almost authentic). Anyone aware of why Pilgrim have different ratings in each of their later Mk 3 manuals? What offset did you get from the other companys? In the end, I might just go for 7" front and back, and just fit wider tyres on the back ones.



08-07-03, 10:37 AM
Could you offer some more clues as to where to see the wheels? "Raceways of Donington" into Google seems to be big on slot cars but not real ones....

14-07-03, 07:49 PM

Try www.raceways.co.uk and tell me what you think, the wheels I am thinking about are called Modular 97. Thanks for the advice on this and the sills by the way. How you manage to get time to spend on the computer and your car I do not know, must be a week since I logged on.



14-07-03, 10:46 PM
Being sort of retired early gives me plenty of time for computers and cars, and I'm not racing to finish the car - it's there for when no-one wants to pay for my services - http://www.tech-ops.co.uk/dvtraining.html - if anyone needs this sort of training (doubtful, I realise).

As for the wheels, I really wanted exactly - exactly! - these ones some months ago, and started a bit of a saga with North Hants Tyres, who really tried hard to get them for me, but it turned out that they are only made for 4x4s, and thus stick out a long way, and don't fit Sumos - that's unless your supplier can find another source. You do need the correct offsets, and certainly not ones which stick out a long way!

15-07-03, 09:40 PM

Nice to know you have some spare time on your hands, wish i could say the same for myself. I take notice of your comment regarding your previous attempt to obtain said wheels. I think I shall take careful measuerments to calculate the offset and will possible end up going for 7" alround with fatter tyres on the rear. As this company are at Donnington Castle, I intend to visit them at the show in September. Will keep you posted on my progress.



23-07-03, 08:58 PM
This afternoon I finally got my Goodrich tyres, and fitted the wheels to the car, only to find that the front ones sit proud of the wheel arches by about 5mm either side.

This is a bit of a pig, as they are exactly as per Pilgrim spec, as discussed above. Not sure what to do now - they look good, but they aren't going to pass the SVA. Looking underneath, I reckon that where Pilgrim say -10 offset, the should say -20, though I suppose that could make the wheel hit the chassis. I could perhaps spread the wheel arch a bit, or maybe go to the SVA with the donor wheels.

As I know I'm not the first - what did everyone else do?

Daz Johnston
24-07-03, 07:54 AM
Is it the tyres or the wheel rims that sit proud of the wheel arches? The SVA test covers the actual wheels and not the tyres. If you have oversize tyres that are wider than the wheels it is not necessarily a fail point. I speak from experience as my Robin Hood failed on this point last year and the SVA tester explained what I had to do to rectify it.

If the tyre extends out further than the wheel arch, they measure it by holding a plumb line against the top edge of the tyre, then measure how far in it is to the wheel rim and to the wheel arch.


24-07-03, 02:47 PM
Thanks Daz

I did the bit with the plumb bob, and if I'm really accurate when I screw the front down, I think I'll be in by 1 or 2mm each side - thats if they haven't changed the rules by then.

I wonder about skimming the surface of the brake disc centres a bit - they seem to be quite fat, and don't help.

Given the number of Sumos, there must be more experiences out there...