Anyone here know of a way to improve front disc brake on '72 Commando and still be mostly stock ?

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Oh yes,
There are 2 ways to improve the disc brake.
The first one certeinly to have a disc without hard chrome.
The second one is to reduce the diameter of the piston of the master brake cylinder to 1/2" as offered by RGM.
These are the most effective ways.
Best regargs and merry "
Christmas wishes
Klaus
 
I wonder if anybody fitted the Lockheed racing brake lever as supplied by RGM, these brake levers have a better length to fulcrum ratio.
Did not try this myself, but it seems to be a simple mod that will probably improve front brake action.
 
Klaus Monning said:
Oh yes,
There are 2 ways to improve the disc brake.
The first one certeinly to have a disc without hard chrome.
The second one is to reduce the diameter of the piston of the master brake cylinder to 1/2" as offered by RGM.
These are the most effective ways.
Best regargs and merry "
Christmas wishes
Klaus
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I’ve done both. Actually a 11mm master cylinder. The smaller master has a far greater effect than chrome removal. My recommendation would be first get the master cylinder piston area to be 27 times smaller than the caliper piston are. The 27:1 ratio is recommended by Vintage Brake. After that, chrome removal or a floating disc.

http://vintagebrake.com/mastercylinder.htm
 
I could never get a chromed disc to work properly. I use a couple if high speed steel Suzuki discs with asbestos pads - gives one-finger operation and for racing, it has to be like that.. Cast Iron discs give more friction, but there are three grades of cast iron. If you get it wrong, the disc can explode off the bike, especially if the disc floats on rivets.
 
Peter R said:
I wonder if anybody fitted the Lockheed racing brake lever as supplied by RGM, these brake levers have a better length to fulcrum ratio.
Did not try this myself, but it seems to be a simple mod that will probably improve front brake action.
Click to expand...

I use those, but the one on my Seeley is designed to be used with one calliper - I use it with two.
 
12" RGM disc , pretech 6 pot calliper , mounts straight to fork leg no ugly brackets ,13mm mastercylinder upgrade , and your Norton will stop better then most modern motorcycles .
 
phippsy said:
12" RGM disc , pretech 6 pot calliper , mounts straight to fork leg no ugly brackets ,13mm mastercylinder upgrade , and your Norton will stop better then most modern motorcycles .
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Yup, I’ve had a pretech / RGM combo before and it really is first class braking!

Does yours mount in front of the fork leg facing forwards? I mounted mine behind the fork leg facing backwards / downwards. The caliper didn’t have any pad springs and the rattling drove me nuts! But I later discovered that it was probably due to the way I’d mounted it (the disc tried to lift the pads and gravity tried to pull them back = constant rattling) !

Doh !
 
Mine mounts downwards /backwards , I have found no problem with ratling, only done a couple of thousand miles so could still be tight , no pad springs like you said.
 
MexicoMike said:
I agree that the resleeve and Ferodo pads (and SS brake lines) will make a substantial improvement. However, I had a resleeve fail and leave me with no front brake at all while riding so I'm a little gun-shy of resleeves! ;) A Brembo MC (available from CNW) will make the front brake perform like a modern front brake but, of course, it doesn't look stock. :(
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richmont said:
Any advice from anyone on improving stopping power on a '72 Commando while still being as close to stock as possible /
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Hi folks, new commando owner here with a bike in need of restoration. As well as lots of other bits to repair/replace I will be doing something to the front brake which everybody says is poor in stock form. I am more concerned to have safe braking rather than it looking original so I am thinking of getting an OEM master cylinder with a 13mm piston, probably off a Honda which means it will be good quality, likely Nissin manufacture then fit a ss braided hose and ferodo pads and maybe a CP caliper. But, has anybody got a solution to retaining the switchblock if you ditch the original master cylinder? I've got an idea to retain it by using the top saddles off a couple of chromed 22mm Munsen rings which will fit the handle bars and the centres of the switch block fixing screws although I will need to elongate the holes in the saddles a little. Does anyone have a better or alternative solution?
 
As i currently have neither master cylinder or calliper I'll soon need to be thinking about purchasing both..
If i buy either the Grimeca or Lockheed calliper from say RGM.. what bore size master do i need to give the best ratio between both??
 
Skorpion said:
But, has anybody got a solution to retaining the switchblock if you ditch the original master cylinder?
Click to expand...

https://www.accessnorton.com/NortonCommando/master-cylinder-repair.25441/#post-419257

olympus said:
As i currently have neither master cylinder or calliper I'll soon need to be thinking about purchasing both..
If i buy either the Grimeca or Lockheed calliper from say RGM.. what bore size master do i need to give the best ratio between both??
Click to expand...

Ratio Chart:
https://www.vintagebrake.com/mastercylinder.htm
 
Can anyone advise me please on the calliper piston diameters as fitted to
1. Grimeca unit
2. Lockheed unit
 
ludwig said:
If you insist on keeping the original caliper , you could cut a step in the pistons over 130 -140 deg. ,
like Porsche , Mercedes , Alfa and others did when they where still using fixed 2 piston calipers .
( remove 1 mm from 6 o'clock to 10.30 on leading edge )
It will improve the brake performance , but it is not a miracle solution either :

Anyone here know of a way to improve front disc brake on '72 Commando and still be mostly stock ?


Anyone here know of a way to improve front disc brake on '72 Commando and still be mostly stock ?


Anyone here know of a way to improve front disc brake on '72 Commando and still be mostly stock ?


Anyone here know of a way to improve front disc brake on '72 Commando and still be mostly stock ?
Click to expand...

So the right (red) edge is towards the front?
 
This article from Pelican Parts might help with understanding the use of a cutout at the leading edge of the caliper puck. Actually it was used to prevent squealing by allowing the brake pad to inflect inward by way of the cutout to disperse the vibration that can cause squealing.

To be very clear, the center point of the cutout edge must directly face the oncoming rotor surface.
 
Skorpion said:
Does anyone have a better or alternative solution?
Click to expand...

Yeah, I bought the master pictured below from Don Pender (madass140 is his name here) It has the perch opposite the reservior to bolt up the stock switch cluster. The reservoir isn't round like the original, but I like it and the piston diameter is smaller than stock, so it has a more powerful feel.

Anyone here know of a way to improve front disc brake on '72 Commando and still be mostly stock ?
 
I am also planning on purchasing Don's excellent M/C / brake assembly. He is a real asset to our bikes for sure.
 
If you want truly excellent brakes with no issues, buy yourself the Production Racer setup from AN. You have the new fork slider to suit the AP (Lockheed) caliper, the caliper, and the floating 11 1/2 inch cast iron disc. Not cheap, but looks great and works a treat. Strong and very linear in operation. Also looks a lot more integrated than the kits with caliper adapters etc. This predates the crappy Norton-Lockheed caliper by a year or two and is so superior I've often wondered why they didn't just use this on the road Nortons instead of developing a whole new inferior brake system where, if you let the pads get too worn, they can be spat out completely.
 
I used a single chromed disc from a GS1000 Suzuki with asbestos Ferodo pads and it was hopeless. I now use two high speed steel discs of a Suzuki with two sets of the same asbestos pads in Lockheed callipers with the same master cylinder. It is one-finger operation and is predictable and can stop the bike like hitting a wall. For racing, it needs to be like that. You can only go as fast as you can brake, engine power is largely irrelevant on tight race circuits.
 
Never use a cast iron disc on a road race motorcycle. There are three common grades of cast iron - if you get the wrong grade the discs can explode off the bike. One of my friends was killed that way. When he passed another of my friends, he was climbing off the back of the bike at extremely high speed. He ended up in the spectator area at the end of Conrod Straight at Bathurst..
 
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