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Wombat rear brake mod

Posted: Thu Jun 06, 2019 8:19 pm
by thirdstone
If you want to reduce the rear brake pedal travel this is an easy mod.
Get some round tube, heat it up and wrap it around the cam. I then welded it in place. Not my idea but it’s a good one.

Re: Wombat rear brake mod

Posted: Fri Jun 07, 2019 2:00 pm
by viclioce
Hmmmm. Great idea!!! :ugeek: Victor

Re: Wombat rear brake mod

Posted: Sat Jun 08, 2019 12:20 am
by Dale
Good tip Kevin, thanks for posting. This seems like a better solution than wrapping the brake cam with a flat material.

Re: Wombat rear brake mod

Posted: Sat Jun 08, 2019 8:18 am
by Bullfrog
I agree. Good tip! I did an enlarged rear brake cam back in the 1970's by building up the cam with brazing rod, then dressing/contouring the enlarged cam with a large flat file. The end result worked well - but your method seems a bit more direct.
Ed

Re: Wombat rear brake mod

Posted: Sat Jun 08, 2019 9:23 am
by givergas
i had to do that also took a piece of flat stock and cut it to fit the size of the brake cam put it in a vise and pounded lightly so it fit tight all the way round, cut it so the ends match then welded it took a file and cleaned it up. i believe i got the idea from some where on the forum. fixed it right up......albert

Re: Wombat rear brake mod

Posted: Sat Jun 08, 2019 9:47 am
by Joe Ormonde
Fixing things can be so rewarding! I needed a Stinger for a 93 Super Rat Pipe. All my tubing was too big or too small. Then I found it! A Road Draft Tube from a 1957 Ford 292! See! One Man`s Junk is another Man`s Treasure! Joe.

Re: Wombat rear brake mod

Posted: Tue Jun 18, 2019 6:44 pm
by Darrell
Here's my latest buildup technique on a 250SL rear brake cam. It's a little bit country but quite functional just the same.

I built up the cam with a sectiom of 1/2" (nominal) ID copper pipe, Type "L" wall thickness. The round pieces on the sides are nail shanks which serve both to center the wrap on the cam and reinforce the lobes under pressure/compression during braking. 50/50 lead/tin solder hold it all together. Brake is working well now, while before the brake shoes only expanded to 131mm when the cam was turned 90 degrees on edge.

Has anybody compared Hodaka brake cam dimensions with another brand? I don't have any non-Hodaka junk laying around to physically measure but I suspect that other makes, e.g. Suzuki, are thicker/taller -- at least that's the impression I get from online photos.
100_3726_1847.JPG

Re: Wombat rear brake mod

Posted: Wed Jun 19, 2019 2:58 am
by Dale
Darrell wrote:Here's my latest buildup technique on a 250SL rear brake cam. It's a little bit country but quite functional just the same.

I built up the cam with a sectiom of 1/2" (nominal) ID copper pipe, Type "L" wall thickness. The round pieces on the sides are nail shanks which serve both to center the wrap on the cam and reinforce the lobes under pressure/compression during braking. 50/50 lead/tin solder hold it all together. Brake is working well now, while before the brake shoes only expanded to 131mm when the cam was turned 90 degrees on edge.

Has anybody compared Hodaka brake cam dimensions with another brand? I don't have any non-Hodaka junk laying around to physically measure but I suspect that other makes, e.g. Suzuki, are thicker/taller -- at least that's the impression I get from online photos.
100_3726_1847.JPG
'
Darrell,
I don't know about other brands of brake cams, but I have compared multiple hodaka brake cams and found that the ones that I have are very inconsistent in both shape and thickness. Some have very rounded edges and others are more squared off at the edges. I believe that the rounded off ones are manufactured that way and not the result of wear.

I have had some success by mixing and matching rear wheel hubs to different brake cams to get enough expansion to get effective braking. I am liking some of these ideas of building up the cam with something that is going to provide better breaking and not live in fear of it coming loose.
Dale

Re: Wombat rear brake mod

Posted: Wed Jun 19, 2019 5:32 am
by MTrat
Another thing that might be considered is shimming up the pivot post on the 'other end' of the brake shoes. It also may even out the brake wear somewhat.