Vintage rules question

Can a vintage class bike use a frame from a different vintage bike with the same age and operating principals? Like using a 1972 Yamaha frame in a 1972 Kawasaki in the V4 class?
Tward the end of the chapter 11 vintage rules in the "Component Specification" section it says "hybrids (a motorcycle comprised of mixed origin or composition) are permitted, provided that the design and operating principle was in use prior to the cutoff date."

 

Sounds like it’s allowed since it’s the same time period.

 

My bighorn was allowed in Vintage and its a F9 motor in a S2 frame. Both Kawasaki but I would say you should be fine!

 

As you can see I'm trying to figure out what my next build will be.

Thanks guys.

 

I suspect the hybrid allowance was put into place to accommodate known combinations, like the Triton and Tribsa. I don't recall any other well known hybrids of that era other than those that used Rickman, Seeley or Egli type frames since most of the Japanese production frames weren't any better than the stock one that matched the motor. The only reason I see to do it now would be to use up left over frames and engines that somebody has laying around. As a vintage type guy, I wouldn't have any problem with it since there are no great 72 combinations which could be better than any other 72 frame with matching engine. Within the vintage rules, getting rid of 72 suspension and brakes is what would make the most difference and that is all open with limits.

Go for it, what engine do you want to put in what frame? I may have some parts you can have.

 

I hesitated to go into detail because I don't want to come across as a dreamer although I do have several race bikes. Some that required a build which I really enjoy doing.

My objective is to make a 2 stroke that fits in V4. One way is to just build a V3 and bump to V4. I don't like this option because V3 restricts you to 18 inch or larger wheels.

I have another way that I believe is completely legal. I am asking about this since I don't want to build something and not be allowed to run it.

The last paragraph of the rules chapter 11, vintage, says: "If a production street model motorcycle is built up to manufacturer road racer specifications it shall be considered a production road racer and shall compete in the next class up. A motorcycle will be considered to built to factory road race specifications if it employs any of the following: dry clutch; factory race cylinders or plated bore cylinders with no iron sleeve; factory or aftermarket racing head."

Based on this I would start with a Kawasaki H1 500 triple. V3 allows it saying: "Pre 1974 2-stroke up to 500cc" The above stated rule says if the bike is built with certain upgrades it will be considered a production road racer and must compete in the next class up. This makes the bike ineligible for V3 but eligible for V4. As you can see it is not a "bump up" since the bike is no longer eligible for V3. Obviously one of the things that would put this bike in V4 is a dry clutch which I could add. Instead of the dry clutch I would prefer to put a race frame in it. I could make or buy a copy of an H1R or H1RA frame. Or maybe a custom frame of my own that started as a RD350 frame.

OK, I spilled it. Can I run a version of this 500cc two stroke in V4?

 

I don't currently have a V4 bike, so I say go ahead. If I did have a V4 bike I would say go ahead, it would be cool.

 

or you could buy my suzuki and race it v3,4 or whatever else, i did race a triple in a framecrafters custom frame at a few events last year, 4,5

 

What kinda Suzuki?

 

a cool one
.

 

Hey Tom,
Did you know they make this stuff that comes in spray cans, so your bike can be all one color, not 4?
The T500 is cool.

 

i think that if i dont sell it that im going to invest in a few cans of krylon . at least get the fuel tank and tail piece to match. my stuff always looks crap.

 

Very cool.

 

Yes.

Cheers,

Dave

 

the suzuki sold to a uscra member , i bought a hd to race next year with the $$$

 

An HD what?

 

86 sportster, should be ready by spring

 

.............................................new bars are on order. will need tires, steering damp. belly pan, etc, etc, etc

 

Can't get much different than a two stroke with a Harley.

I am very curious as to how it does and in what class you will run.