Kawi2strokes.com Forum

Yes, best of luck in the races, sir.

Another issue mot many realize with the drum brakes, as the friction increases the heat and distortion in the drum, the spoke tension also tries to expand the drum/hub as well. Lose-lose situation, even when we used to use Metal Frictions (Seattle, Washington) shoe linings, which were the best you could use. they had Ferodo, Velve-Touch, Raybestos, and others, and could line any basic shoe.

You all have good valid points. I have done plenty of research and done all I can do
I even trebled the size of the intake scoop and drilled holes in the hub to let the extra air escape
But this hasn’t helped.
Heat is definitely the problem as first two corners the brake is OK, bad after that.
Weight?
My manual says a stock bike is 423lb dry. My bike as is,is 339lbs wet, half full tank. 165lb front, 174lb rear.
The brembo calipers are very very light. I had same brembos on my Suzuki gs750 racer and those brakes were absolutely awesome. Might be good enough to run single disc. Problem is I have to run a non floating unvented period disc. It would end up warping. I know those discs are heavy, but they are also big which is good. I recon I’ll end up 10lbs heavier on front giving 50-50 weight distribution, which is what you want. The extra rotating weight will effect/slow the turn in, but turns in great at the moment. A small price to pay for decent brakes.
Can’t wait.
+I am on a diet

Even with the 4 leading shoe brakes on the front if the H1R, braking was fantastic for the first 10 turns, then, fully dangerous. Same with the first Suzuki GT750 street bike, they had a version of the 4 leading shoe setups, not great.

And i believe the suzuki 4 leader was very heavy.
Really my only other option is the Grimeca 4 leader hub (maybe the Grimeca is what was on your H1R?) These can be bought new, but they are big dollars.
All i can say is thank god for the 1972 Moto Guzzi V7 sport as this is the bike that makes the brembo PO8s legal. that was the first bike to get them as a factory option.

H1R ran a factory Kawasaki 4LS race specific brake. The Suzuki 4LS was heavy, too heavy.

The things you do when you dont have much to do....
Mind you, there was a reason for all that butchery. The filter guards are cos my race boot kept wearing holes in the filter.
The river mark is for looks/air circulation about the ignition area, while providing a little protection.
No excuse for the holes............except i had nothing to do.

WOW Awesome pics

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1975 S3 project bike
1974 H1 project bike
1972 Yamaha R5
1974 Yamaha RD350

A very common mod to an H racer ignition cover, which was not close to a street bike cover, was to add a number of 1 inch holes radially, on the outer edge, then line with screen door screen, to help keep the CDI magneto cool. Another racer part was a sprocket cover that just covered the upper part of the cavity, so debris wouldn't be thrown into the carb inlets.

Your mods are very nice.

Just stuff we did to make parts better.

I wish you had nothing to do in my garage!!!

Hmm neat never heard that before sounds so reasonable . Ya think that might be where the Widowmaker name started as in loose spokes

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1975 S3 project bike
1974 H1 project bike
1972 Yamaha R5
1974 Yamaha RD350