The Place

What's with the 7" wide wheel rims, where has that come from what's wrong with 5"/5.5" wide wheels that have been used since the start of the crmc.

Can't answer that but I believe that the maximum tread width of 5 1/2 " max still applies?

I'm staying out of this one. Where's Sidecar Bloke when we need him

He'll be along

Wheels may be of the following diameters: 10", 12", 13", 15", 16", 18" or 19". Any currently available type may be used, with the following provisos: the width of the tyre must be in keeping with the period of the machine, and in particular in the case of 10",12",13" and 15" wheels the width of the tread in contact with the track shall not be wider than 140mm or 5.5 inches. Maximum acceptable rim width is 7”. Slicks (or hand-cut slicks) are not permitted on any wheel.


And as Steve says I am sure Ian will be along at some point. If you have any concerns you could give him a call

Terry Windle never made Imps with a 10" rear wheel. The first Imp he made was for Stuart Pearson in 1972. That bike had a 10" front and chair, and a 12" rear with a tyre width of 7"

I had the second one he built to the same spec.

Most of the Windle Imp outfits now raced in the classic club have a 10" rear wheel fitted (inc the one raced by the sidecar bloke) either to comply with CRMC rules or because the 12" rear tyre became unobtainable. To say 10" wheels, or a tyre with a 5.5" tread width is period for these bikes is incorrect.

I understand that the 7" rim size shouldn't effect any of the current competitors. The tyre width limit is still the same.

That's interesting Ed I didn't know that. The lack of decent 12" tyres has caused a lot of problems hasn't it.

Yes it has Simon. I think the IMPs with the 12" tyre was the ideal set up. 10" in the IMP is not ideal ! 13" far from perfect.

Sorry I couldn't join in sooner. At 9.36 p.m. on Friday we were just having a nice meal, having had a 4 hour eligibility meeting in a freezing cold room, to make sure everything was in place for the 4 hour meeting Saturday morning before the 4 hour CRMC AGM, followed by yet another meeting before the presentation dinner, which I think was a great success. Sadly there were a few faces missing but hopefully that will be sorted for next year.

As Ian Tapsell has said, if you do have a problem it is far better to give me a ring, but a very brief synopsis - the rules in the past stated the contact patch of a 10" - 15" tyre should not exceed 5.5 inches. The rules now state exactly the same - nothing changes. The rules on RIM WIDTH in the past - there were none - you could have as wide a rim as you wished. Having spoken to many people, including Terry Windle, I felt that a MAXIMUM 7" RIM - that's not minimum - is wide enough and as Eddy Wright says the very early original Windle Imps had 12 x 7 wheels. If bikes were riding around in the classic period with 7" rims, and I feel they were, we don't want to introduce a narrower rim width making a large chunk of bikes that have been racing for many many years inelligible.

Various people have approached me this season about their concerns over excessively wide wheels being used, so I put in place a MAXIMUM width and am still getting flack!! So would you prefer I removed the 7" limit and allowed people to go back to any width goes.

Ian

P.S. For the attention of Honda riders - CR Carburettors - the CRMC does not allow the use of CR Carburettors in the Classic classes. I appreciate that they were seen on the grid in 2010 whilst clarification was sought, but this was an interim measure and for 2011 and the appreciable future they are inelligible. The CR carbs with no ticklers appear to have been manufactured in the early 1980's. If you run a pre-1972 engine you should have pre-72 carbs.

Many thanks Ian Oh yes, I'd forgotten about the pre-meeting about meetings, then the meeting and ... etc, etc Not to mention the two or sometimes once weekly meetings at Rugby Post House Hotel.

Hi Ian.

Thanks for that it makes it clear.

However the situation still remains that teams running the 13x7 wheels are dependant on one tyre. There are no other all weather racing tyres available.

More and more teams are using 13" x 7" wheels including this years CRMC Champion. My new bike will have them, and I know Mike Richards is building a few that will join us next season.

My concern is not getting another inch of rubber on the track. It is this "What do we do if Avon cease production, have a strike, or some delay ?"

Should this happen we would lose 50% of the current grid, and I'm sure neither you or the CRMC would welcome that. The Yokohama fits a 13"x7" wheel measured accross the sidewalls it is the same width as the Avon, however the contact patch is 1" wider. In the name of common sense this tyre should be considered.

The current rules of a 7" rim width would stop the use of any wider tyre,and give the teams with 13" wheels more choice.

Hi Ed,

Having spoken to one or two people at the Dinner Dance we have spent the last couple of hours surfing the net - in fact all we had to do was open the Demon Tweeks catalogue to give you a 100% increase in your tyre choice. The Dunlop Racing 450M 13 CR65 gives a 5" footprint - the recommended rim size is from 4 - 7.5 inches with the optimum size 5.5". Clearly we have to hope that the present eligibility bloke and his successor would use common sense should the Avon ACB9 or any other bit of the bike become unobtainable.

Clearly we will have to agree to differ whether the Yokohama A048R should be allowed in now or not. Should no other tyre be available the slight over-width we would have to live with. One concern I would have, however, in recommending it, according to Yokohama's specification:

"Please note - the Yokohama A048R tyre is designed for road racing/track days use in dry conditions only, and not intended for high speed use on wet roads/tracks."

Ian

Eddy surely if that many teams are going to be running 13" wheels it would be insane for Avon to stop making suitable tyres? If ever they do I am sure another suitable tyre could be sourced?

Miuke Richards is indeed building further 13" wheel machines. However he is also (and has previously) built 10" wheels outfits