Greetings S. D.
I race CCS Florida {am}, Super Twins and Formula 40.
A friend of mine restores old Honda's, and now has purchased 2 old bikes he wants me to race next year with AHRMA in addition to my CCS events.
He has looked on thier website, rulebook ect., as have I, and feels he can not get the details of which class the bike can be run in, Formula 750, Sportsman ect. and what mods can be made, frame mods, wheels, brakes period seat ect.
One is a 1978 F2, the other is a K1.
One part I read,section 10, paragraph 6, states that to run F. 750 has to be pre- 1972? Not sure.
After reading some of your post, sounds like your the guy to ask.
If you could offer any info into this matter it would be greatly appreciated.
Thanks.
Henry Madsen #296 am Jacksonville, Florida
Ok, I'm not a complete expert...
Yeah, Formula 750... Those are single overhead cam bikes. I don't know exactly how long they made them. Later model stuff fits into the new Vintage Superbike rules...
Formula classes are based on that year. 1972, and like design. So, as an example, F500, a KH500 Kawasaki triple is allowed because of like design. I've raced a CB400F...that is based on like design of the CB350 four even though the bike was made from '74 to '76.
That make sense? It can be really confusing.
K1 CB750 is an early one right? Got to watch what you're gonna do and the wheel sizes. That should be a lot of what you're gonna watch for.
You have more info?
Dave, I have a question for ya if you willing to answer ;)
On a stock shock for a 03 R6, what is the optimal set up for the shock length, eye to eye?
Here is the situation:
I got a penske for a 99-02. The 03 shock is a bit shorter. Penske can convert it to fit the 03 for some $$. They are shortening the shaft and chaging the bushings. But the 02 shock is only a little bit longer. So, can I just change the ride height on the 02 shock to make it shorter, short enough to fit the 03? Just wondering... I have both shock in hand, they are not more than 1/2 inch difference, but I need to know what would the good race set up is for the 03.
thanks
Well, it's not a CB750 question...
And it's one I have to decline to answer.
First, I haven't heard a common number for the '03 R6.
Could I measure mine? Sure, but the GMD optimization of my chassis comes from http://4and6.com , as does Larry Dennings.
So, that is really their property that I won't give out.
Internally, the dampening might need to be different because of the difference in the leverage ratio in the shock linkage...Doubt that the linkages are exactly the same. I know the '03 swingarm is longer and that the swingarm pivot is closer to the countershaft. Does make a difference.
Thanks for your input Dave.
His plan is to take the 78 CB750F3 SOHC engine {the strongest one} and put in in a K1 frame.
He said the K1 frame he picked up was too rusted so is looking for another.
CB 750 ID's
69 KO & Sandcast
70-K1
71-K1
72-K2
73-K3
76-78 F Series {SOHC} F1,F2,F3
Guess he needs to call one of those #'s to find out about wheels and the rest.
I had a 1973 1/2 Cb 750, had over 100,000 miles on it, only rebuilding engine once, great bike back then. Let my Brother to drag race it in Gainseville and it blew upon him, rubber seals failed I think.
Thanks to ya, and have a nice Holiday.
Henry Madsen #296
Ok, well, I'm sure the K series is F750 legal. Running an F series...you need to talk to John Goodpaster at AHRMA. His number should be on their webite...
http://www.ahrma.org
But it still might be easier running the whole F series CB in Heavyweight Vintage Superbike.
Wheel sizes for F750 front 2.15 inches rear 3.00 max... 18's are going to be the best bet. I think the front is a 19 stock. Expensive to make changes.
I think you can run 17's in Vintage Superbike. But might be like 3 inch front and 4 inch rear. But lots more options...and time is running out.