Commando drum brakes

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NJ71commando

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Finally got the Commando i have been working on running and out on the road. Im new to Nortons but have had 2 Triumphs.

Went for a 50 mile ride yesterday and on the way back my front drum started sticking. From the service manuals it looks like the springs might be shot. The pads dont disengage when you release the brake handle. I will be spending some of this week removing the wheel and repairing the drum. As Nortons (mine included) are notoriously bad brakers what upgrades would you guys recommend? Are there any specialized tools i need?

BTW the bike is a 1971 commando cafe. I have been lurking around as i get my bike going and i thank you all for all the anonymous help.
 
Option 3-

Dismantle the brake assembly, clean it thoroughly, inspect the fit between all moving parts and replace any sloppy parts, inspect and replace any cracked parts, replace the brake shoes with Ferrodo parts, and re-assemble with proper lube on all moving surfaces.

Install a new heavy duty cable and adjust properly.

Your brakes will be fine.
 
A lack of grease at the cam will make the brake stay on. I am betting it is not the springs but go for it. I wrote something a long time ago about how to sand in your shoes to fit the drum. It's in the archives.
 
As Nortons (mine included) are notoriously bad brakers what upgrades would you guys recommend?
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Ron gave you the best advice, so far. The stock Norton disc brake is worse than a properly setup stock drum, so don't spend money on it. A Brembo disc setup is a wonderful stopper. Well worth the money, IMO. For the purists who insist on model correct drums, http://www.vintagebrake.com/is the answer, hands down.
 
In case it isn't painfully obvious, I offered option 3 BECAUSE I'M CHEAP!

Hey, nothing wrong with economical solutions, as long as they work.
 
Owning a well setup Norton is not cheap. When it comes to stopping power, that's no time to chintz on money. I doubt there's anyone who ever thought, just before he slammed into another vehicle, boy I'm glad I saved $700 on the front brake. I see other areas where one can compromise, brakes are not one of them, not for me anyway.

I think the problem with some Norton owners is they think you have to live with poor braking performance. It's quite the opposite, you may die because of poor brake performance.
 
I don't mean to sound condescending, but the front drum brake is a fairly simple device. If someone is asking how to make it work, then I think it is time to have an expert take a look at it.

I agree with Jim. The front brake is not an area you want to compromise.

Paul, I'm at least as cheap as you claim to be! Your option is a good one, but you omitted arcing the shoes and turning the drum if necessary. Also the adjustment of the linkage of the twin leading shoes can be tricky. Addition of the stiffening kit also helps. If you haven't done this before, Mercury Morris at Vintage Brake can have the wheel back to you and working like you can't believe before you have figured out which way to adjust the linkage.

I'm reminded of that old racer's adage.... If you want to go quicker, get better brakes!
 
Simple it may be, but I never had much luck getting that drum brake to work. I checked with that vintagebrake guy back in 2004 and he quoted a three month turnaround and $500 to do the job. Then I'd still have to learn how to adjust it correctly.

So I put a disk on the bike. I have a custom setup similar to Ron's but using Nissan components instead of Brembo. After selling off the drum brake parts on ebay it was surprisingly economical. It stops too!

Debby
 
It costs nothing but a pair of brake shoes and 2 hours work to do the "option 3", then decide if you need to improve on what CAN BE a nice OEM brake if cleaned and adjusted properly by following simple instructions in the shop manual.

I'm not saying everyone shouldn't have the best they can have, I'm just saying if you can take a first step in improving your situation at no detriment to the next step (vintage brake rebuilder could use good new shoes you've already bought), why not?

If you've got the budget to go with a disc, by all means disregard the above.
 
I've asked this before. Does anyone know why Norton first put the disc on the right side? Why are all the rest, that I know of, single discs on the left side? My guess is Norton first put the disc on the right because it was cheaper to do so.
 

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JimC said:
Does anyone know why Norton first put the disc on the right side?
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Possibly because the right-hand side would have been the traditional side for a Norton front brake? As the earlier Norton drums also had the brake plate and brake mechanism on the right, that way there is no crossing-over of the brake cable (or disc hydraulic line) which, as you say could have been partly down to cost?



JimC said:
Why are all the rest, that I know of, single discs on the left side?
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The odd one out is actually the '75-on 850 MkIII (and possibly some late MkII's?) which had the disc on the left. '72/'73/'74 discs were fitted on the right-hand side
 
grandpaul said:
It costs nothing but a pair of brake shoes and 2 hours work to do the "option 3", then decide if you need to improve on what CAN BE a nice OEM brake if cleaned and adjusted properly by following simple instructions in the shop manual.
Click to expand...

Yup, been there, done that, got the greasy t-shirt, but didn't get a good brake. It took me a lot more than two hours, too. I also bought a new brake cable without the inline brake switch (some say that makes a significant improvement) but failed to obtain any noticeable difference from it.

Never did find anyone willing to turn my out-of-round brake drum. That might have helped a bit.

Love my disk brake, and it wasn't really very expensive, either!

Debby
 
JimC said:
I've asked this before. Does anyone know why Norton first put the disc on the right side? Why are all the rest, that I know of, single discs on the left side? My guess is Norton first put the disc on the right because it was cheaper to do so.
Click to expand...

If you look at all the old bikes that had a single disk on front, the front and rear brakes are invariably on opposite sides of the bike. My GS1000, for example, has the front disk on the left and the rear disk on the right. I've been told they did that to balance torque reactions from the two brakes.

That's my guess as to why Norton put it on the right side initially, then moved it to the other side for the Mk3 (on which the rear disk brake is located on the right side).

Debby
 
Debby is correct. Bikes with a single brake on the front, whether disc or drum, typically had the rear brake on the opposite side to balance out torque reaction. The reason why the MkIII switched the front to the left is because the rear disc is on the right. Japanese bikes with a single front brake usually had it on the left, because the rear brake pedal was on the right, often actuating the brake by a mechanical linkage rather than a cable.

Bikes with dual front brakes usually put the single rear brake on the most convenient side, working around the drive system.

On a sport bike, the rear brake is sparingly used. The rear tire handles the acceleration, the front the deceleration - that's why the treads are reversed front to rear.
 
BillT said:
whether disc or drum, typically had the rear brake on the opposite side to balance out torque reaction.

Japanese bikes with a single front brake usually had it on the left,
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I would certainly not disagree with that in the case of the 850 Mk III as that is the generally accepted reason for them doing it, but for every bike with its front and rear brakes on opposite sides, there appears to be an equal number that have them on the same side (certainly drum/drum or disc/drum) including many Japanese, British & German bikes etc..
The first Triumphs with a front disc brake had it mounted on the left side, opposite to the previous R/H front drum brake, the same side as the rear (left foot) drum brake, which was three years before they fitted a rear R/H disc? Was there any forward planning involved in them fitting that front disc on the left, three years early, maybe?
 
I'm struggling with a force diagram that proves that the "torque" is balanced when the discs are on opposite sides. That doesn't mean that such a diagram doesn't exist. So, if anyone has a braking system force diagram, please post it.
 
Given that the torque generated while braking are dramatically different, front to back, I have a tough time with the "torque diagram". In the windmills of my mind I seem to recall, very vaguely, an article about m/c front disc brake position, left to right, affecting handling. Unfortunately, that's all I recall. From casual observation, it appears that early disc brake models were either side, whereas later models are all on the left. I believe all single disc brakes are on the left on today's bikes, regardless of rear brake position. I have never seen a motocrosser with a right front brake. Maybe Mike "Mercury" Morris of Vintage Brake would have an answer.
 
I can't comment on the theory of front brake position, but having a Mk3 originally with a left front brake and now a Mk2 850 with a rear disc putting both front and rear on the right, I can tell no difference in handling.

Perhaps it was a perceived "aesthetics" issue?
 
Harley has models with rear brake on either side. Sportster left front, left rear, big H-Ds left front, right rear. For some reason manufacters continue to mount the front disc on the left, regardless of where the rear is. Since all master cylinders are on the right it would be cheaper not to crossover and put the disc on the right.
 
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