Rear drum brake

YING

YING

Pittsboro,NC
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When adjusting the rear brake I keep getting a tight spot. I have tried 2 different backing plates along with 3 different sets of shoes.New drum with less than 3,000 miles on it. I know these brakes are marginal but should work better than what I have.
Any suggestions on what I am missing.All other procedures are correct.
Thanks,
Mike
 
YING said:
When adjusting the rear brake I keep getting a tight spot. I have tried 2 different backing plates along with 3 different sets of shoes.New drum with less than 3,000 miles on it. I know these brakes are marginal but should work better than what I have.
Any suggestions on what I am missing.All other procedures are correct.
Thanks,
Mike
Click to expand...
You are using the correct method?
Hold the brake applied & tighten the axle?
 
Do you centralise the shoes while tightening the axle? If not you're likely to get your symptoms.
Norman White's book covers it but the page referencing is a bit wrong, which Norman kindly clarified:
robs ss

Post in thread 'Question - Norman White Manual'

Regarding the "rather more complicated procedure" in post #1, I have received the prompt and kind response from Norman White who has agreed to my posting his response:
Hello Rob,

Sharron from Crowood Press has forwarded to me your question on Norton Commando rear brake centralising which I raised in my book. Yes my direction is a tad misleading and I should have directed you to chapter 15 page 216 centre paragraph. The process IS similar to the front drum brake however as you will note on page 216, while centralising the rear brake as you would the front brake, attention must also be paid...
  • Like
Cheers Mike 👍
 
I have followed all the procedures with chain tension,wheel alignment,etc.but I still have a tight spot when adjusting the rear brake.Am I the only one who has experienced this problem.Could my drum need checking as far as being out of round? I understand this brake is not the best but mine sucks!
Thanks,
Mike
 
And if the centralising does not intially work then enlarge the axle hole in the middle of the backing plate so it can move more.
 
YING said:
When adjusting the rear brake I keep getting a tight spot. I have tried 2 different backing plates along with 3 different sets of shoes.New drum with less than 3,000 miles on it. I know these brakes are marginal but should work better than what I have.
Any suggestions on what I am missing.All other procedures are correct.
Thanks,
Mike
Click to expand...
Mike
Can you describe your symptoms precisely.
You say "tight spot" but what are you actually feeling? Is there a consistent position of the wheel where it rubs? Use the valve stem for reference.
...and for approximately how many degrees is it rubbing and not rubbing?
Is it only one spot each revolution?
Cheers
Rob
 
Hi Mike:

I did have what may be a similar problem with my 1974 MKII 850. Whatever I tried I ended up with very poor rear brake performance, this despite having another Norton that I have often removed the rear wheel and the rear brake works very well, (for an old brit bike).

With the bike on the center stand and rotating the rear wheel by hand, I noticed that while the rear wheel ran true, the rear chain was wobbling slightly from side to side. Clearly the brake drum was not aligned correctly. After many failed attempts to get the drum running true, I ended up installing another brake drum and the problem immediately went away! The issue ended up being a small deformation of the brake drum collar that mates with the base of the brake drum stub axle base. Not sure how the deformation could have occurred, although judging by other issues with the bike, the previous owner was a 1000 lb gorilla.

Procedure that works for me is tightening the two bolts in stages, (like torquing up a cylinder head) always while pressing hard on the rear brake pedal to keep the drum centered. Between nipping up the bolts, frequent wheel rotations to determine if the wheel and brake drum are running true and to cause the brake pads to contact different portions of the drum.

Hope this helps

Cheers,

James
 
Last edited:
YING said:
When adjusting the rear brake I keep getting a tight spot. I have tried 2 different backing plates along with 3 different sets of shoes.New drum with less than 3,000 miles on it. I know these brakes are marginal but should work better than what I have.
Any suggestions on what I am missing.All other procedures are correct.
Thanks,
Mike
Click to expand...
If you take a look at my thread cNw #101 you see that I had this very issue and I posted a short video. Every bloody time I tightened up the final wheel nut (left side) I either ended up with a knock or the shoe rubbed in one spot.

I asked Matt for advise and this was his reply;

“As far as rear wheel tightening, this is how I prefer to do it. Not saying its per the book, but it works for me. This is assuming the right side axle was pulled out and you are just re-installing the rear wheel assembly.

1. Insert/tighten the right side first to make sure its properly engaged in the stubby, left side, axle. Do not tighten all the way. The left side nut is loose during this since it floats and this will make it easier for the right side axle to engage.

2. Tighten the left nut all the way. This will secure the brake assembly against the swing arm and then tighten the right axle all the way. This will drive the sprocket pins into the hub and seat them.

4. Loosen the right axle slightly.

5. Loosen the left side nut some and spin the rear wheel rapidly. Apply rear brake and hold firm while tightening the left nut again. What this process will do is allow the brake shoes to center the brake drum/sprocket over the shoes. Since the rear hub/sprocket is essentially floating, this is important to make sure the drum/sprocket is not off center

6. Tighten the right side all the way.

So its a bit of a process side to side but because of the two piece axle and the floating drum, you just want to make sure things are seated and centered

Matt”

Following the above not only did I end up with neither rub nor knock, my brake actually works!

This issue I figured was the spindle was too loose before applying brake and tightening the right side. I’ve had the wheel off since to fix the horn but not the hub so it held its adjustment just fine.

When I asked him to define “slightly” he said;

'Some' and 'slightly' could be translated to 'a bit' or 'a tad'. Maybe 'barely' or 'just'. One of my friends says a 'skoach' but he's from the south and they can't really talk down there. If it was volume on your stereo...1-10, it would be a 2

Bottom line....just loosen in up....'slightly'.

Do not go by the adjusters. I like to align the tire so you have equal space between the guard and tire on left and between the swing arm and tire on the right.
 
Hortons Norton said:
As you tighten the axle make sure the brake lever is pushed down hard, this should take two people unless you have really long arms. And start with both sides snug not really loose. Then tighten both sides.
Chuck.
Click to expand...
I use my left foot on the brake pedal, right foot on the ground and position my chest above the seat, face over the rear fender, a wrench in each hand. Quick & easy
 
Britstuff said:
Hi Mike:

I did have what may be a similar problem with my 1974 MKII 850. Whatever I tried I ended up with very poor rear brake performance, this despite having another Norton that I have often removed the rear wheel and the rear brake works very well, (for an old brit bike).

With the bike on the center stand and rotating the rear wheel by hand, I noticed that while the rear wheel ran true, the rear chain was wobbling slightly from side to side. Clearly the brake drum was not aligned correctly. After many failed attempts to get the drum running true, I ended up installing another brake drum and the problem immediately went away! The issue ended up being a small deformation of the brake drum collar that mates with the base of the brake drum stub axle base. Not sure how the deformation could have occurred, although judging by other issues with the bike, the previous owner was a 1000 lb gorilla.

Procedure that works for me is tightening the two bolts in stages, (like torquing up a cylinder head) always while pressing hard on the rear brake pedal to keep the drum centered. Between nipping up the bolts, frequent wheel rotations to determine if the wheel and brake drum are running true and to cause the brake pads to contact different portions of the drum.

Hope this helps

Cheers,

James
Click to expand...
James,
I think that my problem could very well be with the drum.It is a AN drum that is fairly new but may have been a little off when it was made. I am going to check with the vendor and see what he says. Thanks for your reply. I have gone over all the recommendations and still have the same results.

Mike
 
YING said:
James,
I think that my problem could very well be with the drum.It is a AN drum that is fairly new but may have been a little off when it was made. I am going to check with the vendor and see what he says. Thanks for your reply. I have gone over all the recommendations and still have the same results.

Mike
Click to expand...
Mike, does the issue manifest itself in real life / actual use, or just when you’re looking for it?
As concours said, it may be perfectly fine / normal.
 
Fast Eddie said:
Mike, does the issue manifest itself in real life / actual use, or just when you’re looking for it?
As concours said, it may be perfectly fine / normal.
Click to expand...
Nigel,
After adjusting the brake pedal to the point where the brake just starts to drag and then going out on the bike I have to put extreme pressure on the pedal to get it to work at all.Something is definitely wrong.This is with new shoes and a fairly new drum.To get the wheel to lock up I need to put my heel on the pedal!
I am going to remove the whole assembly again to see if I can figure out what is incorrect.
Thanks for the replies.
Mike
 
YING said:
Nigel,
After adjusting the brake pedal to the point where the brake just starts to drag and then going out on the bike I have to put extreme pressure on the pedal to get it to work at all.Something is definitely wrong.This is with new shoes and a fairly new drum.To get the wheel to lock up I need to put my heel on the pedal!
I am going to remove the whole assembly again to see if I can figure out what is incorrect.
Thanks for the replies.
Mike
Click to expand...
Hmmm… I can’t offer any advice over that already given, particularly as my rear brake is also shite !
 
YING said:
James,
I think that my problem could very well be with the drum.It is a AN drum that is fairly new but may have been a little off when it was made. I am going to check with the vendor and see what he says. Thanks for your reply. I have gone over all the recommendations and still have the same results.

Mike
Click to expand...
Hi Mike:

Before I fixed the problem on my bike the rear brake was hopeless and felt just like you describe in your recent reply to @Fast Eddie (Nigel). It was obvious something was not right. Sure, Norton rear drum brakes ain't great, but mine was almost non-existent. After replacing the brake drum the rear brake works like my other Norton, i.e. reasonably effective (for an old brit bike) and (most importantly in my mind) getting better every time I take it out for a spin as the brake shoes are now presumably actually bedding in!

For me, the light bulb moment was discovering that when I rotated the rear wheel, the rear chain / brake drum wobbled slightly from side to side. Oddly enough the rear brake did not pulsate, it was just rubbish.

My new brake drum came from AN, (by way of Coventry spares) and works great.

Does anyone actually turn brake drums anymore? Assuming mine was warped, I was hoping to get mine checked out by a local brake shop. However, everyone I went to looked at me like I was from another planet. Consequently I took the "hail mary" option and bought a new drum, which fortunately fixed the problem. It took further head scratching to later realize that the drum was not warped, but that the brake drum collar was ever so slightly damaged / deformed.

Cheers,

James
 
Last edited:
Mike,

I replaced my rear shoes as they were squealing badly when used. But locking the rear wheel then was easy when braking

The new shoes are silent but they need a lot of force and and I won't be able to lock the wheel until the pads bed in and conform to the radius of the drum.
I did read in a thread where someone glued emery paper to the inside of their drum and then turned the pads against this to true the pads to the drum

Dennis
 
DennisMo said:
Mike,

I replaced my rear shoes as they were squealing badly when used. But locking the rear wheel then was easy when braking

The new shoes are silent but they need a lot of force and and I won't be able to lock the wheel until the pads bed in and conform to the radius of the drum.
I did read in a thread where someone glued emery paper to the inside of their drum and then turned the pads against this to true the pads to the drum

Dennis
Click to expand...
Dennis,
How long should it take to bed in a set of new shoes?I had it out for a couple of hours and it still has this problem.If I can’t see what is causing my grief I am going to try the sandpaper in the drum procedure.
Mike
 
By now if you take it apart and inspect you should either see witness marks where there are parts touching stopping the shoes from fully moving or on the shoes see how much of their circumference is actually touching the drum from the wear marks. If the wear marks show the shoes are not full mated to the drum then they either need arcing or the hole in the centre of the brakeplate needs opening out to allow the shoes to centralise.
 

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