steve Cunningham Posted April 23, 2001 Share Posted April 23, 2001 Could anybody please advise the correct offset for the following wheels 13 x 81/2" rear Proposed tyres Avon ACB10's 13x 61/2" Front Proposed purchase superlites or minilites / compomotive ML's does anybody have any experience or recommendations Regards Steve Link to comment Share on other sites More sharing options...
R2D2 Posted April 23, 2001 Share Posted April 23, 2001 I bought a set of Minilites last year. 6" for the front and 7" for the rear. I chose ET19 for the 6" and ET25 for the 7". I don't know what I would chose for the 8.5" though. The Minilites were a little disappointing as the finish was quite poor and I have had the wheels nylon coated in silver to improve their appearance. the other thing that I found quite surprising was the weight. The 6" wheels are heavier than than the 7" wheels, obviously due to changes in the die. I was offered two different qualities of wheel by Minilite. A "road wheel" which isn't heat treated and a "competition" wheel which is heat treated. Nearly all aluminium wheels are cast from LM25 and the difference in both strength and impact resistance btween the "as cast" and heat treated condition (TF) is quite significant and I wouldn't entertain using a wheel which wasn't heat treated. The Compomotive ML is also quite heavy and they are commonly used for Historic Rallying. I think the wide section wheels are generally too heavy. Whichever wheel you finally choose, I would ask the weights before you buy as I think there may be quite some difference. I think that the Minilite, KN, Compomotive and Raceline wheels are all cast in the same foundry. My 7" Minilites have a KN logo cast into the inner hub of the wheel and they turned up in scruffy Raceline boxes. (Not too impressive for a "premium" product) I waited more than 6 weeks for the delivery of my wheels and it was quite evident that they had been rushed when they did arrive. The paint was quite poor and the "fettling" of the casting was not too clever. (Tech-del did send me some tickets to the Autosport show as compensation.) If I were going to buy new wheels again I think I would choose Superlite as they seem to have a more consistent product range and a better finish.(I would actually choose Dymags if I won the lottery!) I have also seen Panasports in the States and the finish is excellent but I think that delivery takes forever. Link to comment Share on other sites More sharing options...
VC Posted April 23, 2001 Share Posted April 23, 2001 Steve I measured my rims at the weekend - 6.5 fronts, 8.5 rears. The measurements (offsets)are at work. I will post them tomorrow. I've also been doing some shopping around for wheels. Again I'll post details tomorrow. Best bets for really light wheels seemed to be Ultralites made by Superlite - 3 piece very light-weight - mention Kit Car magazine and you'll get 10% discount. Price c£155-£165 per wheel pre discount and pre VAT. Their Superlite wheels are also good (and a lot cheaper). They have a website www.superlite-wheels.com or call Karen on 01452 414465. Alternatively if you want some R500 mag rims get them direct from the manufacturer, Mike Barnby 01634 711801 for £171 - £191 per wheel plus VAT delivery end of next week. He will know what offset you need as he supplies Caterham. Alternatively look around for some second hand SLR wheels - hard to come by but not impossible, I managed to find some today. Link to comment Share on other sites More sharing options...
VC Posted April 24, 2001 Share Posted April 24, 2001 Measured from edge of rim to hub facing (+/- 2mm): Front 115mm Rear 140mm Link to comment Share on other sites More sharing options...
Paul McKenzie Posted April 24, 2001 Share Posted April 24, 2001 VC, What sizes and make of tyres are you using on these rims? Thanks Link to comment Share on other sites More sharing options...
VC Posted April 24, 2001 Share Posted April 24, 2001 I am using Avon CR500's 175/55/13 front, 205/55/13 rear - they seem the best compromise around between a wet and dry tyre. I seem to have eaten the rears after not many miles though! ACB10 7x13 and 9x13 will fit on the same rims (orig spec for SLR). If you are going for Avons the guys at their motorsport distributers (BMTR in Birmingham) are really helpful - see the Avon Racing website for contact details. I spoke to a chap called Dave Wooton. Link to comment Share on other sites More sharing options...
elie boone Posted April 25, 2001 Share Posted April 25, 2001 My panasport wheels did arrive today after 7 MONTHS waiting they are indeed great but most of all light 7"x13" =5.2 kg On the inside is marked offset 16. Link to comment Share on other sites More sharing options...
Number Six Posted April 27, 2001 Share Posted April 27, 2001 Dymags aren't much more expensive than the Barnby jobs ... way to go. Andy Link to comment Share on other sites More sharing options...
Mr Locust Posted May 2, 2001 Share Posted May 2, 2001 My Locust uses Triumph front uprights as per the Caterham and is fitted with a set of 5 Compomotive ML in 5.5" x 13 ET 12 mm offset Triumph/Marina hub fitting with 185 x 70 r12 tyres. The silver finish is excellent and has proved durable for the last 3 winters without a blemish (daily driver all year round until last year). With any alloy wheel manufacturer I would suggest you look at the quality of the back of the spokes as well as the finish on the front - when I collected the Compomotive wheels, one had a surface breaking pore in the casting on the back of a spoke at the junction with the rim - they made a replacement pretty quickly and were vey apologetic! As regards offset, I can only comment that when I borrowed a set of 6 x 13 ET 19 mm offset wheels (whilst waiting for the Compomotives to arrive) the steering felt totally different becoming heavy, overly sensitive to road camber changes and kicking back through the steering wheel on bumps as small as cats eyes! The front wheel offfset you require is determined by geometry of the top and bottom pivots on the front upright in relation to the stub axle and this is fixed unless you modify the upright - from experience, only deviate from the standard offset if the wider tyre you intend to fit will foul the wishbone on full lock and keep the deviation to the minimum. Measure the existing gap as a starting point and see if half the extra width of the wider tyre takes up the clearance. If there will still be a gap with the wider rubber fitted specfy the offset as per existing wheel. Beware - excessive offset will ruin the feel of the steering! Remember that as an alternative to increasing the offset you can fit shims to the rack restricting the steering lock to stop tyres rubbing on wishbones. Within reason, offset on the back wheel is easier as it is more a case of keeping the wheel under the arch to achieve the desired track width. Failing that - if you dont want to work it all out for yourself by experiment - talk to the lads at Compomotive who were very helpful. Though strangely it was cheaper to buy through Larkspeed than direct from the factory. Compomotive website has a reasonble explanation of how to determine offset values for a wheel see http://www.comp.co.uk/. Hope these inane ramblings are of some help Best Regards Ian Link to comment Share on other sites More sharing options...
Number Six Posted May 2, 2001 Share Posted May 2, 2001 Thank you, Mr. Locust. Andy Link to comment Share on other sites More sharing options...
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