How to disassemble rear wheel brake plate off rear sprocket (2014)

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SvenSven

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I have a 73 850. I have the rear axle off, the rear wheel off, I need to now have a closer look in the rear hub and remove the "Rear Brake Plate" off the "Rear Sprocket/Brakedrum Assy" where the brake shoes reside. I'll be darned but there must be a trick. Add to the lack of details in the aging manuals and aging graphics and picture... I cant get the cover off.


My rear sprocket has always had a slight wobble. As a result my rear chain always rubs a tad against the chain cover etc. So, I'm meticulously trying to go through all the rear wheel parts on the axle including the dummy etc.

Cheers
SvenSven
-->FJ
 
Re: How to disassemble rear wheel brake plate off rear sproc

take the chain off, disconnect the brake cable and remove the large nut on the dummy axle. The brake drum/sprocket assembly should fall off.
 
Re: How to disassemble rear wheel brake plate off rear sproc

I just did this (going to the 1-piece madass rear axle). If the axle nut is off the stub axle then the brake plate should just lift right off. I don't think I had to do anything else. I do know the outside arm to the brake shoe pivot can get offset slightly and may be rubbing on the stub axle. You can tap it so it lines up with the hole in the brake plate which may help.

Russ
 
Re: How to disassemble rear wheel brake plate off rear sproc

Sometimes It can be a bitch to remove the rear brake backing plate from the drum. I think the shoes get stuck on ridges of the drum. I may have resorted to gently prying it off gently with a couple tire irons wrapped with a little duct tape being careful not to damage anything. Also try working the drum brake lever when removing the backing plate so the shoes retract fully.
 
Re: How to disassemble rear wheel brake plate off rear sproc

Thanks all. Yes it was stuck and it was a bitch. Issue resolved. Thanks again.
Cheers SvenSven
-->FJ
 
Re: How to disassemble rear wheel brake plate off rear sproc

You might look into the double row bearing. Just recently My sprocket seemed out of round, the chain would go tight and then loose.
Thought the drum was bad even though it was just replaced.
The double row bearing was bad. I replaced it and now it is true. No more wobble or out of roundness.
They make sealed ones that slip right in without machining.
Got mine from Fair Spares in Ca.
 
Re: How to disassemble rear wheel brake plate off rear sproc

Thanks. Mine already had the fancy near new double row sealed bearing. Seems the issue was worn 42 teeth rear sprocket/drum brake housing. The area around the dummy axle within the old hosing was loose and off kilter. But let me be clear, even with all new parts there is still a good deal of even 360-degree wobble. It is designed to freely wobble by quite a margin.
SvenSven

-->FJ
 
mschmitz57 said:
Re: How to disassemble rear wheel brake plate off rear sproc

Sometimes It can be a bitch to remove the rear brake backing plate from the drum. I think the shoes get stuck on ridges of the drum. I may have resorted to gently prying it off gently with a couple tire irons wrapped with a little duct tape being careful not to damage anything. Also try working the drum brake lever when removing the backing plate so the shoes retract fully.
Click to expand...


So.... once the rear brake assembly is off the bike, I should be able to separate the cover (with chain sprockets) from the base (housing the shoes)... by gently prying them apart? I'll try this tonight.
 
When the brake cable is removed the actuating arm is pulled back by the spring effectively holding the brakes on, but in a backwards way. Move the brake arm slightly and the shoes will release from the drum. Easier done than said.
 
Landspeedracer said:
When the brake cable is removed the actuating arm is pulled back by the spring effectively holding the brakes on, but in a backwards way. Move the brake arm slightly and the shoes will release from the drum. Easier done than said.
Click to expand...
Really... how is mine set up so differently with the cable removed the external & internal spring pull the shoes inwards (away from the drum) until the flats of the shoe cam plates lie flat against the flat of the cam???
 
olympus said:
Really... how is mine set up so differently with the cable removed the external & internal spring pull the shoes inwards (away from the drum) until the flats of the shoe cam plates lie flat against the flat of the cam???
Click to expand...

Then yours is not the same as my 72 and 74, on both of these if you remove the cable the spring on the external arm takes the arm past the neutral point and the shoes expand again. So I also need to pull the arm back a bit to get the neutral point with the shoes flat on the cam plates so the brakeplate can be pulled off.
 
FJ. With the right hand bolt/axle removed from the wheel etc, the drum will wobble around. The left hand axle bolt doesnt hold the drum, until the main through axle bolt has been fitted and tightened. Is that what you are looking at. Thats the way it is designed.
Dereck
 
kommando said:
Then yours is not the same as my 72 and 74, on both of these if you remove the cable the spring on the external arm takes the arm past the neutral point and the shoes expand again. So I also need to pull the arm back a bit to get the neutral point with the shoes flat on the cam plates so the brakeplate can be pulled off.
Click to expand...

I have never seen this on a Commando rear brake. I would suggest that your arm return spring is too strong or your brake shoe return springs too weak. Or a combination of the two.

Ian
 
Nortoniggy said:
I have never seen this on a Commando rear brake. I would suggest that your arm return spring is too strong or your brake shoe return springs too weak. Or a combination of the two.

Ian
Click to expand...
No, springs are original and correct, also get the same on my BSA and Triumph rear brakes with the same type setup. The return spring has to be strong enough to return the weight of the brake pedal plus a safety margin, if not the brake stays on.
 
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To be fair i diddnt check this point before stripping. Both the internal & external springs i have replaced with genuine AN product
The camshaft is free to rotate and suitably lubricated. But my set up does not allow the lever to be turned (by spring) past the "neutral position"
Pull the lever forward or indeed push it backwards it always return to the same neutral position
 
Last edited:
kommando said:
No, springs are original and correct, also get the same on my BSA and Triumph rear brakes with the same type setup. The return spring has to be strong enough to return the weight of the brake pedal plus a safety margin, if not the brake stays on.
Click to expand...

With the adjuster slacked off or removed the springs should center the cam and the shoes will be fully retracted.
 
I would also suggest the dangers if the cable should break or become detached.... the spring could pull the brake shoes into a lightly applied condition
Having the brake applied like this just doesn't sound right.
 
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