Atom drum brake help

[Dowie Soetenga]

I need some help with my Atom drum brake set up. I picked up a NOS rear atom drum brake. I made custom rocker plates and spacers to run it as a front brake. The drum brake is just not stopping very well when moving forward. It seems to work better in reverse. Are these drum brakes directional? Is is possible that I need to just flip the hub around 180 degrees to make it work better? Any advice to make this drum brake work better as a front brake would really be appreciated.

 

[CCR]

you do have a drum stop (pin or strap) that keeps the brake parts from spinning right ?
can you adjust your cable more ?

otherwise id just check your pads, they should work in any direction, but just for giggles i would flip it and see, it looks like your drive side is reversed from how it would sit in the rear. and if its just a single pivot pad inside, that might make a difference.

edit...
just checked the atom hub ive got and it has full floating pads, so i dont think that the directional thing would be a problem

 

[scrumblero]

Not sure if it matters but your definitely running it opposite the way they were originally installed.. :roll:

 

[Dowie Soetenga]

you do have a drum stop (pin or strap) that keeps the brake parts from spinning right ?
can you adjust your cable more ?

otherwise id just check your pads, they should work in any direction, but just for giggles i would flip it and see, it looks like your drive side is reversed from how it would sit in the rear. and if its just a single pivot pad inside, that might make a difference.

edit...
just checked the atom hub ive got and it has full floating pads, so i dont think that the directional thing would be a problem

Thanks for the feedback. I do have the arm pinned in place so the drum housing cannot spin. I have the cable adjusted perfectly as well. I'm going to try flipping the drum 180 degrees to the other side. This would be the correct side if I was running it as a rear. I'll let you know if there is a big difference or not. I'm hoping so.

 

[B607]

Nice ride! I'd get killed riding something like that. :shock: No motors for me. I notice you have a Monark springer. I hope it's an original and not one of those bad welded repops. Gary

 

[Dowie Soetenga]

you do have a drum stop (pin or strap) that keeps the brake parts from spinning right ?
can you adjust your cable more ?

otherwise id just check your pads, they should work in any direction, but just for giggles i would flip it and see, it looks like your drive side is reversed from how it would sit in the rear. and if its just a single pivot pad inside, that might make a difference.

edit...
just checked the atom hub ive got and it has full floating pads, so i dont think that the directional thing would be a problem

Well, I tried flipping my atom drum brake assembly 180 degrees and it doesn't make a difference. I think I'll have to just settle for the brake dragging vs. locking the wheel. Has anyone ever tried increasing the actuating lever arm on the drum itself? I think I might try this.

 

[user 135]

Here is a nice write up on how to get better performance from the drum brake. This link and many great threads can be found in the How-To Manual at the top of the How To section;

http://bikesmithdesign.com/tips/drum-brakes.html

 

[Dowie Soetenga]

Here is a nice write up on how to get better performance from the drum brake. This link and many great threads can be found in the How-To Manual at the top of the How To section;

http://bikesmithdesign.com/tips/drum-brakes.html

Here's my finished set up for running a rear atom drum brake on the front. Everything works well except for stopping power. The rocker arms, spacers, shoulder bolts, and drum support arm is all custom. Thanks for the link on tweaking the shoes and related geometry. I will work on that next.

 

[scrumblero]

did you try loosening the the drum side locknut and re-tightening it with the brakes applied to line up the drum? I leave the other side bolted up, and just loosen the axle and locknut on the one side. do the shoes look like they are making full contact? If they're new shoes you may have to re-arc them a little..

 

[B607]

If the brake pads have had oil on them they are probably ruined. I know this from working on my '48 Ford 8N tractor. You might try removing the pads and soaking them in laquer thinner or acetone for a bit if you think oil could be the problem. Gary

 

[Beau]

The thing is, drum brakes don't work good in the beginning. Even my brand new Sturmey Archer isn't that great. I have done everything to make it work better and they don't. Just like drums on a motorcycle or car. Disks is what you want.

 

[Dowie Soetenga]

The thing is, drum brakes don't work good in the beginning. Even my brand new Sturmey Archer isn't that great. I have done everything to make it work better and they don't. Just like drums on a motorcycle or car. Disks is what you want.

Thanks. I have a 1931 Model A with drum brakes and it took a while to get them working well. After about 100 miles, with adjustments, they started to work great. I just want to make sure there isn't something I'm missing with this Atom brake. I'm getting good shoe contact, but they are brand new. New old Stock. Maybe I should just let them break in a little.

On a side note; I'm planning on running a more robust brake on the rear. Not a disc, but a modern mountain bike rim brake. I'll hide it so it's not so visible...but I need to stop right?

 

[scrumblero]

if they are new shoes, they will definitely get better after a little use..

 

[B607]

The thing is, drum brakes don't work good in the beginning. Even my brand new Sturmey Archer isn't that great. I have done everything to make it work better and they don't. Just like drums on a motorcycle or car. Disks is what you want.

My drum brake off a moped will stop you on a dime. If it had a heavier cable and lever, it would throw you over the handlebars. Gary