Kawasaki H1 1971

[Skub]

I was able to lock the front and fall off when a dog ran out in front of me...

Result! I'm pretty sure as the brakes are,I'd wait to fall off after hitting the dog.

[JackyJoll]

An 8” (or nearly 8”) twin leading shoe brake should work well enough for sensible road riding, though it’ll get hot if you have racing daydreams and brake into all the corners.

Obviously it has to be adjusted so that both shoes actually meet the drum, but even then linings can take a few hundred miles to bed into the exact curvature.

[mangocrazy]

Obviously it has to be adjusted so that both shoes actually meet the drum, but even then linings can take a few hundred miles to bed into the exact curvature.

^^^^
This.

Good luck doing it though, it's a fiddly job and very easy to make the braking performance worse. I'd be inclined to get some engineer's blue, paint it on the drum, reassemble, ride it for a bit and see if all the blue has been cleaned off. That would be a start.

[Count Steer]

Obviously it has to be adjusted so that both shoes actually meet the drum, but even then linings can take a few hundred miles to bed into the exact curvature.

^^^^
This.

Good luck doing it though, it's a fiddly job and very easy to make the braking performance worse. I'd be inclined to get some engineer's blue, paint it on the drum, reassemble, ride it for a bit and see if all the blue has been cleaned off. That would be a start.

Puzzled. That will tell you if the drum is out of round ie if part never touches the pads but if part of the pads touches the drum (across the width of the drum) and the drum is round won't that clean all the blue off? ie it won't tell you if all the pads surface is in contact. Am I missing something?

[Noggin]

Sounds blooming awesome! Love to read about making someone smile THAT much!!! (I know, the smile goes all through )

[mangocrazy]

Obviously it has to be adjusted so that both shoes actually meet the drum, but even then linings can take a few hundred miles to bed into the exact curvature.

^^^^
This.

Good luck doing it though, it's a fiddly job and very easy to make the braking performance worse. I'd be inclined to get some engineer's blue, paint it on the drum, reassemble, ride it for a bit and see if all the blue has been cleaned off. That would be a start.

Puzzled. That will tell you if the drum is out of round ie if part never touches the pads but if part of the pads touches the drum (across the width of the drum) and the drum is round won't that clean all the blue off? ie it won't tell you if all the pads surface is in contact. Am I missing something?

Yes, I was suggesting that to test roundness of the drum. If you want to test whether all the shoe surface is touching the drum it might be possible to paint the shoes, but the blue would probably soak into the shoe material and negate the test. It might also cause the brakes to grab violently, throw you off and kill you.

Perhaps...

[JackyJoll]

You’ll know if the drum is out of round, when you try to brake.

[Ian]

Also you said it's 'only' done 800 miles since a total rebuild
If the pads are pretty hard you may still not have full contact across the whole pad as others have suggested
If you take the wheel out you will see where contact is occurring on the shores without resorting to blue, it will be darker and shinier where it has made contact
You could find someone to reline them with a softer compound ( or AM4 asbestos for the win, none of this modern shite )
Glad you are enjoying it

[asmethurst99]

Nice one and happy birthday

[mangocrazy]

You’ll know if the drum is out of round, when you try to brake.

What would be the symptoms?

[Yorick]

You’ll know if the drum is out of round, when you try to brake.

What would be the symptoms?

Bart is a fat guy. Marj has blue hair.

[JackyJoll]

You’ll know if the drum is out of round, when you try to brake.

What would be the symptoms?

On-off-on-off juddering.

I’m surprised at the need for explanation. When you have the juddering going on when you brake, that’s when you address the oval drum problem.

[mangocrazy]

You’ll know if the drum is out of round, when you try to brake.

What would be the symptoms?

On-off-on-off juddering.

I’m surprised at the need for explanation. When you have the juddering going on when you brake, that’s when you address the oval drum problem.

It's been nearly 50 years since I rode a bike with a drum front brake, and I can't remember ever experiencing that kind of sensation. So not really surprising.

[Supermofo]

Skub, that looks and sounds great (experience and sound).

As it's 1971 you can blitz around the ULEZ stinking up the place with 2 stroke goodness Not much of a holiday mind

[roadster]

Who is Tom Pemberton?

Tom Pemberton was the only person I remember who could race these competitively. I did run in the same race once at Brands hatch. He won easily enough and I was placed somewhere about half a lap behind on a Honda 500 four. ( Long lap on the Brands full circuit !)

[Yorick]

Who is Tom Pemberton?

Look a bit lower down

[Horse]

Lower bars and longer shocks will help avoid the wobbles

Poor man's fix: 5:15 on

[Skub]

Lower bars and longer shocks will help avoid the wobbles

Poor man's fix: 5:15 on

On my Z1 I had high bars,a worn rear tyre and a topbox,I'd only have been about 10 stone too. It bucked me off at around 120mph.

The perfect storm.

[mangocrazy]

Tony Dunnell was leading the 1969 500cc Proddy TT by a fair margin and looked set to win until his H1 spat him off at the 33rd milestone on the 2nd lap...

[Skub]

Tony Dunnell was leading the 1969 500cc Proddy TT by a fair margin and looked set to win until his H1 spat him off at the 33rd milestone on the 2nd lap...

The most spectacular one I recall was an early Fireblade going into one and ejecting the rider down Bray hill at a rate of knots.