CR480 Front Brake Upgrades?

[Tahitian_Red]

Anyone made improvements to their 1983 CR480 front brake setup?

Is it possible to adapt an '81-83 Yamaha Double Leading Shoe front brake to the CR480 Showa forks?

[smed]

Anyone made improvements to their 1983 CR480 front brake setup?

Is it possible to adapt an '81-83 Yamaha Double Leading Shoe front brake to the CR480 Showa forks?

I have just switched from a 83 honda TLS set up to a 81 Yam complete front end & TLS set up on my 79 CR250 & am feeling at this stage that the Honda brake was better,the shoes are still wearing in so will reserve my judgement till then (maybe I have cocked up the adjustment but I reckon it's right,new genuine yam cable & SBS shoes ), I was looking at using the Honda wheel assy in the Yam forks & they are very close with not much to do to adapt,so visa-versa should also work,but not worth it in my experience

[FourstrokeForever]

It took a while and an extra pair of eyes to find what the problem was (is) with the Honda TLS. It seemed no matter what I adjusted and how close the shoes ran to the hub, the brake was always like a wet sponge.
First off....the chamfer on the brake cam has too much radius. Weld it up and make the chamfer more square edged. You end up with much better lift (more pressure) on the shoe.
Secondly, even after doing that, the brake still had no real power. Then I discovered that the edge of the shoes were contacting the very inside edge of the liner where it starts to round to the hub. I made up a spacer to move the backing plate out a bit from the hub. The brake was much better but still not working %100.
Then while I was testing the feel my mate came over for a look at what I had done. He looked at the pivots while I operated the brake and noticed that there was float on the pivots. Wheel out again and sure enough, the brake pivots had way too much tolerance allowing the brake cam to move off axis. We made up some brass bushes and pressed them into the backing plate. And what do you know, I now have a Honda TLS that works as it was designed to. Just as powerful as the Yamaha set up, maybe even a bit better.

[Tahitian_Red]

Hey FourStroke,

Any pics of the modifications? (Bushing, spacer and cam) 

Thanks!

J

[Shane W]

The best way to get around it is to match your shoes to the drum (sanding of the shoe required)... my old Honda SLS work a treat like this.

Shane

[FourstrokeForever]

Hey FourStroke,

Any pics of the modifications? (Bushing, spacer and cam) 

Thanks!

J

I'd have to pull the wheel off the bike to take pics J....... Sorry

[80-85 husky]

the husky guys put some double sided tape in the hub with some emerypaper and bolt it up and then run the hub around with the brakes on to get an exact profile for the shoes / hub. works well except for me...I had new shoes and couldn't fit it all together  but I can lock the brake on the old husky ok so now issue

[sleepy]

the husky guys put some double sided tape in the hub with some emerypaper and bolt it up and then run the hub around with the brakes on to get an exact profile for the shoes / hub. works well except for me...I had new shoes and couldn't fit it all together  but I can lock the brake on the old husky ok so now issue

Wouldn't the thickness of the emery tape and double sided tape make the inside diameter effectivley smaller and then size the shoes incorrectly?

[Momus]

the husky guys put some double sided tape in the hub with some emerypaper and bolt it up and then run the hub around with the brakes on to get an exact profile for the shoes / hub. works well except for me...I had new shoes and couldn't fit it all together  but I can lock the brake on the old husky ok so now issue

Wouldn't the thickness of the emery tape and double sided tape make the inside diameter effectivley smaller and then size the shoes incorrectly?

It would have to do that.

Better bet would be to use  paint marker on the shoes ride and then sand to get conformity. Done this on drum braked race cars where the drum ID had been cleaned up.

[80-85 husky]

I don't think anyone (except husky riders) understands how bad some of the early tls brakes were. while the trick does not make it perfect it has a dramatic effect on some of these brakes which were next to useless until sorted. a lot of old husky riders in the day replaced the tls with the older sls brakes as they couldn't get them right.

[PEZBerq]

I don't think anyone (except husky riders) understands how bad some of the early tls brakes were. while the trick does not make it perfect it has a dramatic effect on some of these brakes which were next to useless until sorted. a lot of old husky riders in the day replaced the tls with the older sls brakes as they couldn't get them right.

Double sided tape thickness is measured in thous  . The emery tape does have measurable thickness - maybe 1mm? I can confirm from doing this many times that it works very well on DLS Huskys. What other method actually applies brake pressure when arcing shoes? It is easy to do and easy to check progress as the shoes are sanded down to full contact. Obviously it does not correct for out of round drums - full machine shop facilities needed for that. Don't knock it until you have tried it is my advice.

Cleaning the residual glue from the double sided tape can be a pain 

[KTM47]

Several things to do.

1.  Make sure the hub braking surface (cast iron inserts) are running true to the bearings.  Machine if needed.

2.  Get some shoes relined or use new ones.  Mount the backing plate in a lathe, put shims in between the shoes and the cam and machine the shoes to the exact size of the inside brake drum.  This will give full contact.