250SL rear brake shoes worn, but actually not.

[Darrell]

There is nearly 1/8" of friction material left on the brake shoes but the brake cam will now rotate up to 90 degrees and yet the lining barely contacts the drum when the brakes are fully actuated. One might conclude that the drum is oversized, but it isn't.

Is there a trick or technique to build up the brake shoe cam contact area? Way back when on this forum (or the Resonator newsletter) I remember that Ed shimmed the pivot end of the shoes with shim material sourced from a beer can.

The current (EBC) brake shoes have about 2,300 highway/dirt combined miles on then, but as I mentioned there is lots of lining left -- but not enough to make proper contact now.

[Zyx]

I have used sheet metal to wrap the cam. Just removed such a repair made in the 70's, and it was still working in this century. Carefully done, it works, but I didn't do the pivot end, just the eccentric.

[Darrell]

Thanks Arizona, I'll try that.

The first idea to cross my mind to build up the brake shoe contacts by JB-welding extra plates onto them. On second thought, I think repeated point-loading from the brake cam could weaken the JB bond in fairly short order.

[Bullfrog]

Jaimie McAdams described doing exactly that . . . JB Weld attachment of accessory liner material to properly prepped stock shoes. He did the actual gluing to the prepped remainder of the stock liner material. He's been running those shoes for years with no problem.

It is worthy of note that he worked diligently to assure FIRM and EVEN clamping pressure on the new liner while the JB Weld cured.

I'm going to try it on my rear brakes . . . and for exactly the same sort of reason as the starting post mentioned.

Ed

[hodakaronwa]

I have run into this situation with a few Hodakas and other vintage bikes. Check the fit of the brake actuator shaft in the bore of the backing plate.
Often the bore fit of the shaft is a contributing problem. It can be re-bushed. In some cases I have brazed up the cam to increase it's width, then use a hand file to shape it to match. I have accomplished the "BEER CAN" trick in desperation when nothing else was available. The aluminum will wear through pretty quickly. This would be my best and most reliable suggestions. I am sure there will be more to come?? "can't wait"

[michael_perrett]

I've welded up the end of the cam lobes with a 7018 rod, turn the ends down on the lathe and finished up with a flat file to contour the ends.
Mike Perrett

[Darrell]

UPDATE: I have to make a partial retraction of my claim that the brake shoes still had ample lining -- I was just looking through the bottom inspection hole in the backing plate when I made that observation.

However, a thorough inspection revealed that the top brake shoe lining is significantly worn -- much more than the bottom shoe which is still at nearly the original thickness. I guess the automotive engineering principle of designing and dedicating primary and secondary brake shoes applies here. The rotation of the brake drum grabs the top shoe after it makes contact and the rotational force pulls the shoe even harder than the actuating force of the cam/expander. That also means that the top shoe is braking harder than the bottom shoe.

And, I suppose the Trail Whale is a bit like stopping a runaway train for these relatively small brakes that are more suited to 100s and 125s. I don't have to tighten up my 94 Wombat brakes nearly as often as its needed on the TW.

But in the meantime, I made a sleeve out of some sheet brass and it fits snuggly over the brake cam. Appears like a built-up brake cam is just one way of expanding the actuating range of the brake shoes and exploiting more of the available lining. The Hodaka Think Tank rumbles on.

[HodakaHughey]

I like the small tips tricks and advice from every readers opinion and run-ins with similar problems and such. As a very green hodaka owner (about a week now) I look forward to expanding my learning with with you all. Believe it or not I tried to talk hodaka with some guys at work (ages 45-65) and some of them had no clue what I was talking about even after doing a google image search and showing them! At 24 years old I felt completely blown away that they hadnt!?!?!? Only a couple of buddies of mine have heard of them but that's simply for the fact they heard the same stories from my dad that I was told. The others think I'm an idiot for buying old torn up broke down dirtbikes... I suppose what I'm trying to say is this forum is one of a few places I can go and talk/learn hodaka and I love it keep it up guys!!

[Darrell]

Here's the brake cam built up with a brass sleeve, and JB-Weld to make sure it stays put. It puts the semi-worn brake shoes back into the adjustable range.

The surprise result is that now the braking performance is more powerful and controllable than it ever was before. Before this addition the brake action was weak and spongy, even after breaking in new shoes.

I consider this a temporary mod since I do quite a bit of highway riding and am not comfortable with an additional component patched into the system that might fail at some point. However I think that some experimenting with the brake cam profiles, e.g., crowning/lobing the flat surface of the cam, might yield some improved braking performance over stock.

[kingdve]

I did this kind of thing "back in the day" on my 1970 A , drums and cam started to wear and brakes wouldnt 'reach" took a piece of copper pipe and wrapped the pivot WaLa brakes again ! Kept a 15 year old kid going ...