Brake rotor replacement

It seems that other than another stock rotor the only other replacement is a Colorado Norton Works set up. Any one know of another source for a floating rotor?

RGM offers a 12" and grimeca caliper, norvil has the 11" setup also

This is just about the ultimate in my book new-front-brake-kit-t15950.html
Made to fit pre Mk3 Commandos, it can with a bit of fiddling also fit those, as you eill see at the end of the thread. Price was $650 plus shipping for forum members. If you have a pre mk3 disc brake bike, the new master cylinder is a direct bolt on as is the rest of the kit.
Stopping power and fade resistance is great.
Looks good too.
Don, please send commission

Glen

I have been using a Suzuki GS1000 master and it works great. Stainless lines and a stock rebuilt caliber. The disk was the weak spot.

Oh, no sale

Don, keep the commision cheque for now.

The norvil lightweight disc is the one then. It gets good and bad reviews.

Glen

Wondering wether ; though not what youre looking for , it may be what it ' fell of ' . various grades & prices .

FRONT BRAKE DISC FIT FOR TRIUMPH HERALD 12/50 1963-1967 272



http://www.ebay.co.uk/bhp/triumph-herald-brake-disc

I have the RGM Grimica set up on my Norton and it works great, I run the whole system and is a good system for the price.

Ashley

The most important part of the processis to run a smaller sized master cylinder.

chasbmw said:

The most important part of the processis to run a smaller sized master cylinder.

Click to expand...

You are entirely correct. You can buy all the highest priced brake components available, but if the caliper and master cylinder do not have the proper ratio you will not have a good stopper. The ratio what is what makes the stock Norton front disc such a poor brake.

In my view the tiny surface area of the pads is what makes the Norton brake so poor. I could have put up with the amount of pressure required, but it was what happened to my brake when really used hard repeatedly that caused the big problem. On the third pull down from 70 mph to about 20 mph (mountain switchbacks) the front brake overheated and went to zero braking.
I chatted with a longtime Commando owner from Oz a couple of weeks ago. He has had the same problem with his 73 which has had various " upgrades" including the stainless line, 13 mm mastercylinder kit and ferodo pads.
While the above changes make the brake feel better for light use, none of the changes make any difference to the larger problem of brake fade.
Looking at the size of that miniscule pad it is a wonder it works at all!

Brake fade is a factor of pad size and composition. Caliper to master cylinder ratio is about pressure generated. The single most important thing in any brake system is applied pressure.

Read this: http://www.vintagebrake.com/mastercylinder.htm

All things aside, if I didn't already have a very good upgraded front brake, I'd buy the system Madass sells in a heart beat. I would like to know the ratio of his caliper to master cylinder first though.

After losing the brakes on the Duffy lake road, I called Vintage brake and had a long talk with the owner. He sold me some of his special pads for the Commando that he felt would cure the overheating problem.
I think they improved the initial grip a little, but the overheating due to tiny surface area is a basic design problem that cannot be fixed with a pad change, mc change or line change.
You can however make the brake feel strong for light, relatively low speed use. After experiencing the fade, I rode the bike as though it had one good stop in it, not two or three.
With the Madass brake I doubt I will ever have the fadeout problem.

Glen

It always seemed a stupid idea to make the pads round instead of square or rectangular. When I used to use my Commando as my only transport the front brake was a nightmare in the winter. The disc used to rust easily in wet weather & then when you applied the brake the narrow bits of the pad at top & bottom wore away quicker than the middle. After a couple of days I ended up with only a thin strip in the centre of braking area on the disc that was being used. I then had to use emery cloth on the disc to get rid of rust & either rub pads flat or replace them. After suffering like this through my first winter I made a suitable bracket and fitted a Lockheed racing caliper which used a rectangular pad & things improved dramatically. I believe the Lockheed uses the same size pistons as the standard Norton caliper, so the improvement is solely down to the shape of the pads. The Grimeca caliper is pretty much identical to the Lockheed. I improved things further with a sleeved down master cylinder.

A sleeved master cylinder with decent caliper & pads makes for a very effective brake using the standard disc.

Ian

When I had cast iron rotors on one of my airheads, I had the rotors zinc plated, this had the effect of really reducing the amount of rust, it's a bit like the original cadmium plating that norton discs were coated with.

Slightly off topic, but as bad as the stock setup is for the front, it is just dandy on the rear. Adding lots pressure is easy with the foot and the rear wheel is lightly loaded when the front brake is doing its job. Add in compression braking and some care has to be taken not to lock the rear wheel with the standard setup. Even the most modern Sportbikes use a fairly small single sided rear brake, not a lot different than the MK3 Commando
So I wonder why CNW makes that very powerful looking MK3 rear brake upgrade kit? It would definitely add bling factor, but a stronger rear brake on the MK3 could actually be a bit of a bad thing.

Glen

Hey,

Even though the size of the brake pad does affect the performance of a brake system, a much bigger pad doesnt mean that the brakes get that much better.

Brembo, arguably the premier brake manufacturer of brake systems in the world, recently developed a 4 pad caliper ( 4 piston each pushing a pad ). It uses 4 individual brake pads and they are only 1 1/8 X 1 1/4 square pads. So the total brake pad surface is actually less than their std 4 piston caliper. having said that, the caliper is really more efficient, especially on the initial brake application.

This due to the fact that its the leading edge of the pad that does the most work, not the overall brake pad surface

Brembo doesnt believe in large pads and thats the reason they dont offer 6 piston calipers (they do for cars only). The very large pad and added weight of a large 6 piston caliper is something that they consider excessive. Maximizing the size/weight/performance ratio for a motor cycle is critical and its a mater of getting a well balanced system as oppopsed to just larger individual parts

I have used the 4-pad caliper on many of my machines in both a single and dual (New CNW Cafe' design) set up and they work extremely well. More braking power with less input.

Matt / Colorado Norton Works

http://www.coloradonortonworks.com

worntorn said:

Slightly off topic, but as bad as the stock setup is for the front, it is just dandy on the rear. Adding lots pressure is easy with the foot and the rear wheel is lightly loaded when the front brake is doing its job. Add in compression braking and some care has to be taken not to lock the rear wheel with the standard setup. Even the most modern Sportbikes use a fairly small single sided rear brake, not a lot different than the MK3 Commando
So I wonder why CNW makes that very powerful looking MK3 rear brake upgrade kit? It would definitely add bling factor, but a stronger rear brake on the MK3 could actually be a bit of a bad thing.

Glen

Click to expand...

I wanted to create a matching rear brake system for our front. The last upgraded version includes a Brembo master cylinder and this was done to once and for all get rid of the poor, original master cylinder.

The fact is that I use a 2 piston caliper back there and even though far more efficient than the stock set up, its well matched and not overly powerful where you will get the feeling it wants to lock up in the back.

The whole idea is great breaking with less input.

Matt / Colorado Norton Works

http://www.coloradonortonworks.com

Well it looks great, but I do feel the standard one is plenty strong. The lighter disc is a big improvement tho, nice to reduce the spinning mass for a whole variety of reasons.

Glen

worntorn said:

Well it looks great, but I do feel the standard one is plenty strong. The lighter disc is a big improvement tho, nice to reduce the spinning mass for a whole variety of reasons.

Glen

Click to expand...

Glen

Have you any ridden any modern bike? If so, what did you think of the brakes on the first stop? How does this compare with your stock Norton disc setup? A properly sized master cylinder, with all else being stock Norton, will get give you near the performance of a modern twin disc setup, at least for the first stop. You may have an issue with fading, depending on your riding style and conditions, but unless your front master cylinder is 27 times smaller than the caliper, in piston area, you don't have an optimum performing front disc brake. In my case, the stock Norton disc brake was piss poor, one stop or multiple stops.

I suspect the CNW/Brembo rear caliper to rear master cylinder has a much closer ratio than 27:1.

Hi Jim

I have two modern bikes, an 05 Triumph Daytona 995i, which has beautiful brakes, light but not touchy. The other bike is an Egli which I built last year. It has brakes from an 03 gixxer, very powerful but a bit touchy, especially since the Egli is about 80 pounds lighter than a Gixxer.
The poor oldstock Norton brake really doesn't compare very well to either, but then it was early days for disc brakes when they were made. I will add that the rear brake on the Norton is as good as either of the modern rear brakes.
The Madass brake is very similar to the Triumph, super strong if you need it but not overly sensitive.
With the Egli I can do a stoppie with one finger, which is not necessarily a good thing!