Original GT40 Wheel & Tyre Size Advice Needed

Racing in a UK pre-1969 Replica and Original Sports Car series we would be very grateful for the precise wheel and tyre sizes for MkI and MkII GT40s up to 1969.

The problem is that some years ago greater numbers of Cobra racers forced through regulations requiring mid-engined cars to abandon our nice Hoosiers and instead run at 1100kgs on 15" rims, maximum 8" wide, and maximum 225x60 Yokohama tyres with predictable results in that every incident becomes an accident and any spin usually ends with an impact.

Vested interests (ie Cobras keeping mid-engined cars slower) disregard caution mooted by tyre manufacturers regarding the behaviour of heavy cars with a pivot point rear of centre being vastly different to those lighter front-engined cars with pivot points far ahead of centre mean we need some hard facts with which to go to battle.

Given the nature of the Series in re-creating 1960s endurance grids we'd like to propose all participants run period wheel and tyre sizes hence needing definitive sizing for MkI and MkII GT40s from their first entry until the end of 1969.

Your kind assistance would be warmly welcomed and appreciated. Kind regards, Bob.




[ February 10, 2002: Message edited by: Bob Sparks ]

[Bill Bayard]

Bob,

Charringtons Motorsports has the original GT40 wheel moulds. They maintain and race prep a few original GT40's as well. They
should be able to give you the info you need.
I believe they are located in Derbyshire, UK.
Good luck! I hope they can help you. They
have a website, but I don't have the address.

Phone: 44(0)1773 590525
email: info@cchltd.demon.co.uk

Bill

[ February 10, 2002: Message edited by: Bill Bayard ]

Thanks for the info Bill, it's very much appreciated. Contact with manufacturers for this kind of detailed information, particularly when you're not going to be a customer, is understandably not welcomed and we still await responses from these previous approaches, hence our forum plea.
Kind regards, Bob.

[Julian West]

Bob,

The series looks fascinating, which club runs the series & could you post some dates/venues so I can spectate?

regards,

This Series has been around since about 1988 and I entered in 1992. It's now known as the Sports Racing GT Challenge and 2002 Fixtures may be found at:- http://www.srgtc.org.uk/Calendar.htm

The Series website is not always up-to-date but nevertheless is at http://www.srgtc.org.uk/

All are welcome and, whilst things may be a little fraught from time to time in the general mayhem of British motorsport, we hope you will make yourselves known.

Kind regards, Bob.

[ February 10, 2002: Message edited by: Bob Sparks ]

[ February 10, 2002: Message edited by: Bob Sparks ]

Hi Malcolm - nice to know you're still breathing. And yes, I'm still growing old disgracefully. I too recall setting up the car for two persons and chucking it about to find adhesion limits - sorry pal, you were expendable, the guys from Gulf Oil marketing weren't. Er .. waddyamean 'tyres I now hate'? you missed out loathe, detest .... etc. Thanks for the info but as usual have lent books out and surprise, nothing when I need it, just like my tools. I've bought some post-histroic Dunlops from the guys at Silverstone for Spa and Zandvoorte and indeed they are very helpful - what we need is to point to something in print. Thnaks for your kind wishes; I look forward to seeing you around. Kind regards, Bob.

[ February 11, 2002: Message edited by: Bob Sparks ]

[Chris Melia]

Hi Bob

Gt40 P/1080, P1081, P1082, P1083, P1084 were all supplied withJWAE (BRM) 10"x15" Front and 12"x15" rear wheels.
P/1082 was supplied with Googyear 10.5" front and 13.7" rear tires.

P/1083 was supplied with Firestone 10.2"
front and 12.2"rears.

Its all in black and white in Ronnie Spain's
Book GT40 An Individual History and Race Record.

Chris

[Chris Melia]

Mr Ronnie Spain just after he signed my book.
Must make it worth a fortune

Chris.

Hi Bob,

Didn't think you were still racing your 40 but had sold it. I am still getting over that lap at Goodwood from quite a few years back when you were practising where the limits were on these skinny tyres you now hate!

I haven't looked but doesn't Ronnie Spains book give details of races with chassis numbers and then a section on each chassis that gives original spec wheels and tyre sizes. Maybe Trevor Legates new book has this info. In my office now and can't check easily! Possibly try the HP tyre Exchange at Silverstone who are historic Dunlop specialists. They seem to be quite knowledgeable about original 40s and their tyres.

Good luck for the season

Malcolm