2018 Vintage Classes

Hi, new guy here on the forum. Raced V6 back in the mid-90s and considering joining up again.
I've done my level best to discern what exactly is going on w/ the vintage classes. I've got a 1981 XS650 bored to a 750 that has a 17x2.5 front and a 17x 3.5 rear, discs at both ends. I was looking at the 2017 rulebook and V4 looked like a legal fit, but it seems that V4 is *absolutely* gone.

Am I right to understand there will be just two Formula classes; up to 500cc and over 500cc?

Do my disc brakes (the front being an oversized supermoto rotor w/ 4 pot caliper) put me out of vintage?

I started putting this thing together using stuff I've had around intending to use it for track days. Then I noticed it would fit in D superbike and thought I'd perhaps race vintage again.

 

Some classes will run combined, but you still have V4, V3, 500GP, V5, V6MW, V6LW, V6HW, V7MW, V8MW, V8 HW and V5. It looks like maximum rotor size is 12 inch, but who will be out there with a tape measure? It also looks like the 4 piston caliper is OK for V4.

 

^^ Thanks!
I just combed through the component specs at the end of the vintage section in the rulebook and it doesn't specifically prohibit 4 pots for V4 and up. I didn't notice the 12" disc restriction; I think mine might actually be legal in that case...I'll have to check. I wasn't real fast "back then" so I doubt it'll be an issue as long as I'm a backmarker.

 

Brakes only slow you down. Big brakes are really bad about that . . . .

I intend to have my V4 bike out this year, and you'll not hear a peep from me about trash can lid size rotors.

Cheers,

Dave

 

Lace up a set of 18's with a 2 pot caliper, and your bike would run v3 also.And be a ringer.....

 

Dave - I appreciate your discretion!

bogganman - While I would likely need the displacement advantage, should it prove effective, the tear-downs would be brutal on my budget
I actually grafted a set of RZ350 wheels onto it after I bought it as a neglected stocker back in 2000. I had concerns about not being able to find good rubber in those sizes and figured I'd use my supermoto hubs with the 17x3.5 front rim on the rear and the 17x2.5 I took off of my DR650. I thought I might be able to find appropriate slicks, but I'm certain I didn't look hard enough.
*sigh* I still miss 591s.

I'm glad to see the sense of humor still present among the vintage community!

 

We're just a bunch of broken old men riding broken old bikes, it's all we've got.

 

Thanks for the clarity Mongo!
Sorry, but I gotta ask, what is a "DH" weekend?

I presume "VMD" is Vintage Motorcycle Days @ Mid Ohio?

 

Thanks again. I just looked over the Talladega schedule and it's all very clear now.
FWIW, compared to the schedule I remember from the 90s, I think this construct is more attractive.

 

Your 750cc is legal in v3. all years of the xs650 are legal. No teardowns necessary. Read the rulebook. Avon tires in a 110/18 and 130/650 18 work great. Or run v4 as it is. Youll be in the same race, just one class up.

 

I saw that XS650s were legal for V3, but I figured going up to a 752 would constitute more than the typical maintenance work allowed. A 75mm bore up to an 81mm seems like a cheater motor, to me anyway. I just want to finish in the rear with less shame
I do see that there is no expressed limit on overbore though...then again the rulebook says one has to presume one cannot do something unless it says you can. I am used to the standard wisdom of V6, 20 years ago, where Superbike rules were assumed and 1mm overbores were the limit.

Could be wrong though; I've hit my head a number of times since then.

 

I just looked up the tires you've mentioned. I probably should've joined up here before lacing up my wheels, but like I said, I was just trying to use stuff I had laying around - the supermoto bike is long gone plus I shaved 16lbs off of the bike just getting rid of the RZ wheels. I've kinda stayed with Dunlops and Metzelers. I tried some other brands (but not Avon) and was disappointed. As Kipling wrote - stay with the devil you know!

 

How about ss rd 250 with a drum?

 

Tear-downs?