Thumb Brakes legal for Vintage?

I would bring it out and play. If someone felt it was giving you some kind of an advantage I guess they could protest you, but it's really not like that in Wera vintage.

 

it was funny to watch how they became all the rage after Honda put one on Doohan's bike back in the '90s, but can't remember seeing any production bikes with them. It may have to do with some law that was passed in the 70s(?) that required left foot shift, right foot brake, left hand clutch and such. I couldn't cite the law but I stumble across it now and then reading about how/why the Sporty switched to left foot shift.
That said, I would bet it's an advantage to those riders/racers who use the rear brake. I doubt it's going to change my riding habits, but I always wondered how much it might have helped me on a dirt track bike or my desert bike.
I'm just looking to fulfill the requirement to have operating front and rear brakes.

 

While I said I would vote no for a V4 bike, the reality is that I really wouldn't care very much. It isn't something I would protest, cause it wouldn't be the difference between beating me or not. If it gets one more bike on the grid, it is ok with me. But if you make it legal, I'll just leave my v4 bike at home and bring a bike for v5 or v3 or v1 or something. The Seca isn't my current favorite anyway.

 

I managed to get a couple of pics on my computer. This is still in mock-up phase more or less, hence the piled up washers until I can turn some proper spacers. The space between the peg and the kicker shaft looks deceptively roomy, but those familiar with the bikes ought to know how tight it can be. I included a shot of the shifter side to show how even a somewhat abbreviated pedal takes up a lot of real estate if one wants a useful control.

 

Use a folding footpeg. Problem solved.

Cheers

Dave

 

I appreciate the suggestion, although the re-formed kicker obviates a folding footpeg. However, if you meant a folding toe peg on the prospective brake pedal, I'll quote an earlier post of mine //A folding peg may work, but if it is configured so that it "falls" into place, or is spring loaded to do such, it would be a major PITA.//
As much as I am entertained by Rube Goldberg machines, I think the level of complexity for the prospective toe peg would be an exercise in vanity.

I am intrigued by the older machines you've mentioned ridden by Surtees, et al. I'm going to have to make some time to see if I can some pics.

 

Thanks 83BSA! I think this might be my favorite racing shot thus far!

 

The bent kicker clears the fixed peg, you'll grab your calf on the way by. A folding footpeg makes sure everything is clear all the time. Ask me how I know . . . .

If you plan on pivoting the brake pedal on the stud with the washers, you can make a U shaped brake arm and bring the toe piece out from the cases. I assume you'll space the brake arm out off the plate such that you can mount your rear master cylinder vertically behind the footpeg, thereby avoiding the exhaust. Otherwise, re-route your exhaust and place the rear master behind the plate.

I can't see all the exhaust, but I'm curious whether it has to be tucked so close to the footpeg. I assume it is a 2 into 1 arrangement that joins beneath the engine. Why not make a high pipe model? Either one each side or 2 into 1 and back alongside one side? I did 2 high pipes - 1 each side - on a PPIHC BSA Twin using XR750 Supertrapp mega's and it looks bad ass. On the other PPIHC BSA Twin, I used TT pipes beneath the engine, and turned out on each side, thereby avoiding controls. Your critical distance is from exhaust valve stem to end of header. After that point, it matters little what you do, altho' you will see a difference between TT, long taper mega and short taper mega. The TT and short taper mega will pull better off the corner; the long taper mega will give better top end.

I understand the conundrum with fitting such items - I've spent long hours on that exact problem. I really don't care about a thumb brake versus other brake setups - they only slow you down. My point is this is vintage racing. How about we keep the bikes vintage? That means period pieces and arrangements. Sure, one can argue all day long about the degree or absence of performance advantage of modern items and devices. But, if an organization is going to claim to have vintage racing, then it needs to be vintage. A lot of folks have gone to considerable lengths to make their vintage bikes work as vintage bikes. And, maybe they don't work as well as they might if they had modern items. But then, that is part of the challenge to vintage racing. At least from my perspective.

Do whatever you like. Mongo will rule however he pleases. People will agree or disagree with me and my perspective. Life will go on. Races will be won and lost. And all that plus $2.09 will get you a cup of coffee at Starbucks.

Cheers,

Dave

 

83BSA, you make a good suggestion with the U-shaped pedal. I kinda wanted to avoid having anything that could be pushed into the side cover for the sake of crash survival though; when I bought the bike, the stock pedal had been shoved into the side cover and cracked gerotor inside the oil pump housing. Still a reasonable idea - my size 11.5 feet might be able to make the stretch.
I found a pic of the bike as it was when I completed it around 15 years ago or so. I took it to a guy asked for a specific header length (don't remember what), told him I wanted it run under the engine and tucked up nice and close. I bought a can for a 96 GSXR 750 just because I like the way it looked and I hadn't seen a streettracker done as such. So the pipe is what the dude welded up and at the time there was no reason to want anything different...plus it seems to work pretty well, so I'm loath to mess with it.

Again, I just wanted to put something together for track days to minimize risk to my 87GSXR with stuff I happened to have around and thought it would be a bonus if it fit in V4...but I'm not super invested either way as far as competition goes at this point in my life.
I agree with the spirit of vintage racing as you've laid it out, and I concede that I may be pushing things at the very least. I'm certainly not looking to effect any rule changes or to create any discord - just didn't want to "cheat".

 

Hell Sean, you know I'll run anything anywhere. I was just bragging about having lots of vintage race bikes that I can run in lots of classes. If a bike with a thumb brake shows up and beats me I wouldn't protest it for that. If it doesn't beat me I don't care.