Topic: switch to rear drum?

[LeoLegendATL]

Im tired of messing with the rear caliper on my 750f, should I be able to just buy the rear drum assembly and hook it up with the according levers?  or is there more to it than that.  Should I just get a new rear wheel or wil the drum assembly just fit over where the rotor went?

[GeorgeK]

Keep the rear disc. It is a much better brake.

[Bodi]

Yeah, best to get the disc working. I've seen lots of questions about going the other way... you're the first I've seen wanting to take the disc off and put a drum on!
The drum brake's drum is actually the entire hub. There's no way to add a drum brake to a disc wheel; you'd have to get an entire hub and respoke the thing to your rim (different spoke lengths too)... so just putting a complete rear wheel including the brake shoe plate on will be better if you really have to have a drum brake. The actuating rod and the pedal assembly would have to be fabricated or adapted, the torque arm would be the least of your worries.

[LeoLegendATL]

ok, ill give it another try, I can't get the damn air out of the thing, and every caliper I get off ebay has a seized piston. ugggghh!!

[bowhunter]

Maybe you could try parking the bike on an incline with the front wheel higher than the front. This would allow the air bubbles to work their way to the master cylinder where you could slowly release them by actuating the brake pedal. It worked for my front disk!

Bowhunter

[rucorey]

If it wasn't for the rear disk on my 750f, the thing would never stop! I had problems with my line, initially. They were cracked but didn't seem to leak, yet there was always air in the line after a few rides. I swapped the line and now the pedal has a great feel all the time and no air get in.

[mick750F]

ok, ill give it another try, I can't get the damn air out of the thing, and every caliper I get off ebay has a seized piston. ugggghh!!

   Are you just having a problem bleeding the system or is something else going on? Bleeding can take a while. Rebuild kits are available for the caliper and should be available for the master cylinder as well.

Mike

[Clyde]

You could replace the caliper with one from a F2 or early CBX/CB900. They are only a single piston caliper, give less trouble and are easier to bleed. They fit straight in.
I used one of a CBX on my K2/F1 special, because the standard one was U/S.
I went the other way and replaced the rear drum with a disc. Either way you need the matching swingarm or you have to weld on a bracket to the existing one, as the drum brake torque rod is underneath whereas the disc is on top.
The hard part would be modifying the pedal/ actuating rod.
Good Luck Clyde

[eldar]

Gee I see nothing wrong with a drum brake for the rear. I can lock my tire up with no problem if i want to. Cant do any better with a disk really. our bikes do not have antilocks so you have to know how much to push the pedal. Lock up is lock up no matter if it is disk or drum. maybe if you ride 2 up all the time, then you MIGHT get better preformance from a disk but you would be better off making sure your front is in top shape.

[dusterdude]

eldar,locking up is what you dont want.a disc brake is a thousand times better than a drum.now,have you tried using a vacuum pump to bleed the brakes?also,check your brake hose and make sure its not collapsing inside.

[mylittleho]

eldar,locking up is what you dont want.a disc brake is a thousand times better than a drum.

I think what he is saying is.. if the drum brake stop/slow down just as easily as disk brake.. why would you feel the need to convert over.. That I can understand..

We had the same discussion on a mustang board about front brakes. my 88 has disk/drum.. and everyone seems to be converting to larger calipers up front.. and it causes problems.. people think bigger brakes are better.. but the fact is that if you upgrade the front brakes to a larger piston and master cylinder.. you have basically made the car HARDER TO STOP.. the extra brake force only makes the brakes pedal more sensitive and the brakes will lock-up faster and cause you to, instead of stopping, to skid.. with the smaller calipers and master cylinder you can modulate the pedal more (longer brake stroke means you can control it better) and can actually stop quicker than with the bigger brakes..

i guess that is the same thing with the rear brakes.. you DON'T want the rears to lock-up.. so a little less braking might be better than too much braking.. in some cases.. especially in emergency situations.. where you might get a little ancy and end up locking up the brakes all around and laying the bike down..

[eldar]

That is it exactly. Stopping power is the works the same way for drums and disks. You can set both to lock or not lock. So unless you add lots of weight, a drum is just as good as a disk and you dont need to bleed it! The back only supplies about 1/4th of your stopping power which is mainly enough to keep proper control of the bike. Do a search on "breaking news". it is about a conversion to dual puck calipers. That will be a better upgrade then doing a disk on the back.

[dusterdude]

and a lot of the stopping power is in the tire too

[eldar]

It is. crappy tires do not stop no matter what you have for brakes.

[mylittleho]

AMEN to that!!!