Commando Rear Brake Drum Advice

DogT · Jan 31, 2013

Arcing the drums wasn't my idea. I read it on this forum a year or more ago. It really does work. My front TLS is now a real brake as opposed to what I used to have, feet dragging on the ground, planning 3 miles ahead and lots of downshifting.

My rear drum must be slightly out of round because I get some rubbing, but I don't feel it on the road. I think that may be the tale, if it's distracting or you notice it on the road, it may be time for a new drum. The other thing is like previous, tighten the drive side stub first, and then the long axle bolt. But it does help to center the drum by tightening the shoes before tightening the axles. I've even heard it can help to enlarge the drum cover hole, apparently sometimes it doesn't allow the shoes and drum to center.

Mine is so old it doesn't even have the bearing in the drum, so yours may be even different than mine. No cush either.

Dave
69S

concours · Jun 20, 2013

So... is there a brand of brake shoe that's better (fitting, first and foremost) than the others? Any to stay away from? Madass made a good point about some FRONT 200mm shoes being sold for an 8" application, bad fit right out of the box. What about rears?

DogT · Jun 20, 2013

I got the RGM front 'high friction' shoes from Commando Specialties. I also got CS rear shoes. Both fit fine. I understand RGM also has 'high friction' rear shoes, but if you look at their rear shoe numbers, it's the same as the front shoes in my book???? I just haven't gotten around to asking them about that. Also their 'high friction' rear shoes appear to be a trade in item, but I'm not sure about that either. Anyhow my CS rear shoes seem to work fine for me. I would like to arc them, I tried the other day when I installed the madass single piece rear axle, but the clearance is so tight I couldn't get the sandpaper in the drum and then put the shoes in.

Does madass have a catalog or where do I find what he offers?

Dave
69S

concours · Jun 21, 2013

No Madass catalog, AFAIK. I'm still running the original rear shoes (1973 date code stamped it) at about 60% left. No brand to stear away from? Emgo or Ferodo... All good?

DogT · Jun 21, 2013

I thought I read recently that someone got some Forodo shoes and they didn't have enough pad on them? I can't vouch for anything other than what I got at CS.

Dave
69S

dero · Jun 22, 2013

Make sure you do as Dog T suggested and tighten the axel while centring the shoes by applying the brake .
I do mine in several stages while turning the wheel , otherwise it acts just like you describe .

JohnTy · Jun 22, 2013

DogT said:
Your drum is most likely out of round where the shoe hits it. The shoes may not contact fully either and they also may not be circular to meet the drum. You can either take it to a brake shop, send it out, or you can do it yourself. Chances are the drum is not that bad. Take some #60 sandpaper, glue it to the drum in strips with some non hardening glue, I used 'tacky glue' from the craft shop. Put it back together, tighten up the brake shoe against the drum as tight as you dare, and then tighten the axles. Now loosen the shoes until you can turn it by hand, and keep turning it as you tighten the brake to grind down the shoes to come into compliance with the drum. A nut driver on the brake adjuster is real handy here. Keep tightening it until you have at least 90% contact between the shoes and the drum. You'll have to take it apart and clean it a few times to see what is happening. Now you will have a better brake, but if the drum is that out of round, it will still drag at certain points. You'll have to get that machined out. Then do the shoes again.

I did my front drum like that and it's a wonderful brake now.

You don't need a subscription to post photos. Send them to photoshop or similar and link to them here. Instructions in the first sticky.

Dave
69S

Am I missing something here? this method would shape the shoes to fit the drum - yes. But if the drum is not round it would do nothing at all to help!
enlighten me please
JohnT

madass140 · Jun 22, 2013

I've never came across out of round rear brake drums and cant see how that would come about.
there doesnt seem to be a problem with rear brake shoes, aftermarket or otherwise. I would guess that the majority of rear shoes sold are Emgo. the drums dont wear much. I think most problems with rear brakes is the installation. A lot of those problems (and others) can be overcome with a One Piece Axle.

concours · Jun 22, 2013

JohnTy said:
DogT said:

Your drum is most likely out of round where the shoe hits it. The shoes may not contact fully either and they also may not be circular to meet the drum. You can either take it to a brake shop, send it out, or you can do it yourself. Chances are the drum is not that bad. Take some #60 sandpaper, glue it to the drum in strips with some non hardening glue, I used 'tacky glue' from the craft shop. Put it back together, tighten up the brake shoe against the drum as tight as you dare, and then tighten the axles. Now loosen the shoes until you can turn it by hand, and keep turning it as you tighten the brake to grind down the shoes to come into compliance with the drum. A nut driver on the brake adjuster is real handy here. Keep tightening it until you have at least 90% contact between the shoes and the drum. You'll have to take it apart and clean it a few times to see what is happening. Now you will have a better brake, but if the drum is that out of round, it will still drag at certain points. You'll have to get that machined out. Then do the shoes again.

I did my front drum like that and it's a wonderful brake now.

You don't need a subscription to post photos. Send them to photoshop or similar and link to them here. Instructions in the first sticky.

Dave
69S

Click to expand...

Am I missing something here? this method would shape the shoes to fit the drum - yes. But if the drum is not round it would do nothing at all to help!
enlighten me please
JohnT

Correct, geometry 101.

concours · Jun 22, 2013

madass140 said:
I've never came across out of round rear brake drums and cant see how that would come about.
there doesnt seem to be a problem with rear brake shoes, aftermarket or otherwise. I would guess that the majority of rear shoes sold are Emgo. the drums dont wear much. I think most problems with rear brakes is the installation. A lot of those problems (and others) can be overcome with a One Piece Axle.

I agree, that drum sprocket casting would likely not go out of round (no spokes pulling like a front drum), and yes, I DO want a one piece axle. :mrgreen:

madass140 · Jun 22, 2013

bit off topic, but i now have One Piece axles for Cush drive, early Commando bolt up and Atlas, 3 different versions.
And i dont believe its possible to pull the front drum out of round through spoke tensioning, I've done zillions of these without drama, maybe some Jap hubs coz some are pretty fragile, Asian manufacturers especially these days will try to save every ounce in material costs to keep production costs low. a bit of a prang and the hubs shatter and the cast in
liner pops out.

DogT · Jun 22, 2013

Well, if making the shoes more in contact the drum is the objective, so what if the drum is not perfect. When I started working on my front TLS, I had maybe 10% of the shoe making contact with the drum, that's both shoes. When I got through, I had over 90% of the shoe making contact with the drum, and the brake then worked completely acceptably for me. It does fade with sustained braking, but hey, it's a drum brake. I'd say it's about 90% better than it used to be, and that wasn't much better than dragging my feet. I can't argue with success or good results. Of course you have to set up the TLS linkage right too. I haven't tried the stiffening kit and don't plan to since it works so good now.

Yes, I could have sent out the whole assembly to Vintage brakes, but I figure that the $10 or so in parts and the 2 hours or so I used to improve my front brake is lots easier on the pocket book than the Vintage Brake price. I didn't know that madass had shaped shoes.

As far as the rear brake, the axle hole in the brake cover plate can keep you from getting the shoes centered with the 'apply brakes and tighten the axle nut' method. Most of them probably need to be opened up a bit. My rear brakes still rub a bit at one place, but I can't get the sandpaper between the shoes and the drum to sand them down a bit. Maybe they'll just have to wear in a bit, but I don't' get any surging brake action. I didn't notice much difference in the original 2 piece vs. the madass single axle as far as centering the brakes, it's just that there's no stub axle to tighten first with the single axle which does make it simpler. Make sure you remove any powder coating on the swing arm axle mounts and on the brake cover plate if you want the single piece axle to snug down right and the spacers to fit right.

Sanding 101.

Dave
69S

concours · Jun 23, 2013

DogT said:
Well, if making the shoes more in contact the drum is the objective, so what if the drum is not perfect. When I started working on my front TLS, I had maybe 10% of the shoe making contact with the drum, that's both shoes. When I got through, I had over 90% of the shoe making contact with the drum, and the brake then worked completely acceptably for me. It does fade with sustained braking, but hey, it's a drum brake. I'd say it's about 90% better than it used to be, and that wasn't much better than dragging my feet. I can't argue with success or good results. Of course you have to set up the TLS linkage right too. I haven't tried the stiffening kit and don't plan to since it works so good now.

Yes, I could have sent out the whole assembly to Vintage brakes, but I figure that the $10 or so in parts and the 2 hours or so I used to improve my front brake is lots easier on the pocket book than the Vintage Brake price. I didn't know that madass had shaped shoes.

As far as the rear brake, the axle hole in the brake cover plate can keep you from getting the shoes centered with the 'apply brakes and tighten the axle nut' method. Most of them probably need to be opened up a bit. My rear brakes still rub a bit at one place, but I can't get the sandpaper between the shoes and the drum to sand them down a bit. Maybe they'll just have to wear in a bit, but I don't' get any surging brake action. I didn't notice much difference in the original 2 piece vs. the madass single axle as far as centering the brakes, it's just that there's no stub axle to tighten first with the single axle which does make it simpler. Make sure you remove any powder coating on the swing arm axle mounts and on the brake cover plate if you want the single piece axle to snug down right and the spacers to fit right.

Sanding 101.

Dave
69S

I agree, arcing the shoes is good practice. Takes away the improper radius problem of poor fitting shoes.

pete.v · Jun 23, 2013

These work right out of the box. I think that a little extra maintenance (cleaning) makes these shoes superior. Copper impregnated. I clean the hub and shoes before and maybe once during the riding season. If there is any advantage to help with the rear braking, cleaning is one of the most effective.

924 063417 RGM HIGH FRICTION REAR BRAKE SHOES C £ 33.00

Commando Rear Brake Drum Advice

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