Front Brake 850 MK3, improve braking (2019)

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I did mine the opposite way around: I had the master cylinder re-sleeved by RGM and the front brake with standard disc & caliper was transformed from 'wooden' to 'plenty of feel' and was more than adequate for solo riding - a huge improvement.
I then went for an RGM floating disc and AP racing caliper combo which gave another 20% stopping power. Another advantage to the caliper upgrade was the choice of pad materials.
As has already been said; front tyre squealing on demand, and very controllable.

Various routes are available for the 13mm master cylinder upgrade - I've used RGM and Madass so far, no problems with either.
Negative comments based on experience are a good way of informing the judgement of any potential customer, but I'd question the value of slagging off something which wasn't actually used, especially when it's sold in good faith.

I think your setup will not disappoint!
 
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FWIW, I have had two (2) sleeved MCs fail. One failed "overnight" in the garage - no brake when I went out to ride. I sent it to the original (well-known) resleever and it was re-sleeved at a cost of 150 bucks. That one failed maybe a year later while on a ride. I went from a normal front brake at one stoplight to NO brake at all at the next one about a mile down the road. Those two lessons pretty much convinced me of the old saying, "Fool me once, shame on you; fool me twice, shame on me! ;)

Obviously plenty of folks have had good luck/performance from re-sleeving but my two experiences changed my view of it completely -resleeving carbs is fine, nothing all that bad can happen if they fail. Brakes failing are, IMO, several orders of magnitude more serious.
 
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like i stated the one time i was brought a madass sleeve kit to use i refused to because it was such a sloppy fit it would almost rattle in the old bore. i do realize that the bore can vary in size and IF yours was a light push fit it MIGHT be OK BUT i want more than a push fit with glue on a brake system. i also have severel bikes running the RGM kit with no issues BUT a master made with the proper size bore is the best option.

Various routes are available for the 13mm master cylinder upgrade - I've used RGM and Madass so far, no problems with either.
Negative comments based on experience are a good way of informing the judgement of any potential customer, but I'd question the value of slagging off something which wasn't actually used, especially when it's sold in good faith.

I think your setup will not disappoint!
 
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like i stated the one time i was brought a madass sleeve kit to use i refused to because it was such a sloppy fit it would almost rattle in the old bore. i do realize that the bore can vary in size and IF yours was a light push fit it MIGHT be OK BUT i want more than a push fit with glue on a brake system. i also have severel bikes running the RGM kit with no issues BUT a master made with the proper size bore is the best option.


“BUT a master made with the proper size bore is the best option.”

Couldn’t agree more. Why introduce a potential catastrophic problem?
 

click

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Dohhhh, I just read your earlier post "I’ve decided what to do! Get the 13mm MK3 master cylinder from AN and a set of Ferodo Platinum pads."

Note to self - pay more attention.

:oops::oops:

;) You & me both :)
 
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I have nearly the identical setup on my 73 850, with an RGM floating disc and bracket. The only difference is, I use an 11 mm m/c.

That is a slightly approach on the master cylinder, and it makes quite a difference.

If you go to the Vintage Brake website and find the table showing master cylinder/caliper ratios, you will find that Mike's recommendation for this caliper is an 11 mm master cylinder with the two piston 41 mm Lockheed caliper to give a 27:1 ratio. http://www.vintagebrake.com/mastercylinder.htm As he says there, for a 41mm Lockheed caliper, " The "sweet spot" formula said a change to a 11 or 12mm master cylinder was in order: my personal preference and recommendation would have been an 11mm. He was able to switch to a 1/2" , and although not ideal, he was keeping the rubber side down." In other words, you can use a 1/2 inch m/c if you want, but that gives diminished performance, and Mike's preference is 11mm or 12 mm. After trying a 13mm m/c, I used this Lockheed caliper and an 11 mm m/c on my AHRMA road race bikes --Triumph 750, and Yamaha 2 stroke--for 25 years, and the braking was always flawless and very, very strong--something like the feel of my modern road racer, far far better than most vintage bikes.

Natch, with that experience, when I put the Lockheed caliper and RGM disc on my Norton, I used an 11 mm m/c. I simply got a current Yamaha motocross master cylinder (it says "11mm" right on it) and fabricated a woven stainless line. You will have to figure out the switchgear, and perhaps fabricate something to fit it, but it is the strength of the brake that is most important, and it is very good--superior to 1/2 or 13mm m/c.
 

Dellis

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The key to sorting the front brake is to move from the 5/8' bore m/c to 1/2" bore m/c. Your choice if you sleeve or fit the AN 13mm m/c but I guarantee you will feel a significant difference, instead of squeeze and hope you get squeeze and stop.

Dave
 
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Master cylinder piston size in relation to caliper piston size is by far the most critical factor in this brake ‘equation’. It’s area of the pistons that determines braking force. The difference in area between a 11mm and a 13mm diameter piston is considerable. 133 sq. mm versus 95 square mm.
 
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If you are improving your braking, you probably need to look out for your steering geometry. I have never ridden a near-standard Commando, but from what Hobot has said, he usually has to reverse-steer to get the bike to tip into corners. Most road bikes are set up to handle like that - if you brake when cranked over, they tend to stand up and go straight. With bikes like that, if you lock a drum brake, you usually crash off the side which is away from the lean. My bike is neutral going into corners if I brake when cranked over, but tightens it's lime if you gas it hard when cranked over when coming out - so it is a much better deal. If you get the trail wrong, it is possible to have the bike bite you when you use the brake in anger and you are going your fastest into a corner. It is a matter of steering trail and the balance of forces. Two factors are important, the engine weight and the centre of gravity of the bike. A heavy engine is probably better than a light one.
 

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Thanks for all the replies.

I've had a look at the Vintage Brake Front Master Cylinder to Wheel Cylinder Ratio Chart.

I'm presuming I have the standard master cylinder which has a 5/8th piston. The Lockheed caliper I have is a twin piston & I believe the pistons are 41mm, so that gives you a ratio of 13.34, hence the 'wooden' feel to the brake.

Bizarely, from my point of view, the 'standard' Norton caliper has two, I believe 44mm pistons which gives a ratio of 15.36, which is going in a better direction than my 'upgraded' setup? I know it's not 'just' about the ratio but it looks like the standard setup would give a better 'feel' to the brake. If you kept the standard disc & just changed the caliper to the one I have, in my mind, that would make the braking worse? or am I missing something??

The 13mm standard master cylinder from Andover Norton would give me a ratio of 19.89 (lets call that 20!!)

I know it's not in the sweet spot ratio of 23-27 but a ratio of 20 should improve the 'feel' of the brake & hopefully stop me a bit quicker.

I appreciate the advice about 12mm master cylinders and even 11mm but for me I'm not looking for another 'project' dealing with the fabrication of a custom bracket to keep the existing switchgear or re-wiring to accept a different switch cluster. I just want to ride the bike as much as I can :)

I tend to plod around on the Norton, I'm not a speed demon! I'm just looking for that extra bit of 'bite' for the occasions when the idiot drivers around me decide to do stupid things!!! and of course when I do stupid things:rolleyes:
 
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“I tend to plod around on the Norton, I'm not a speed demon! I'm just looking for that extra bit of 'bite' for the occasions when the idiot drivers around me decide to do stupid things!!! and of course when I do stupid things”

That’s when you wished you had the best brake money can buy.
 
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"I appreciate the advice about 12mm master cylinders and even 11mm but for me I'm not looking for another 'project' dealing with the fabrication of a custom bracket to keep the existing switchgear or re-wiring to accept a different switch cluster."

The CNW adapter for their Brembo master cylinder simply bolts to the master cylinder and then you attach the OEM switchgear to it on the handlebar, just as you attach the OEM switchgear to the OEM master cylinder. No fabricating or futzing around required! :)
 
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"I appreciate the advice about 12mm master cylinders and even 11mm but for me I'm not looking for another 'project' dealing with the fabrication of a custom bracket to keep the existing switchgear or re-wiring to accept a different switch cluster."

The CNW adapter for their Brembo master cylinder simply bolts to the master cylinder and then you attach the OEM switchgear to it on the handlebar, just as you attach the OEM switchgear to the OEM master cylinder. No fabricating or futzing around required! :)


What’s the piston diameter of the CNW Brembo master?
 

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"I appreciate the advice about 12mm master cylinders and even 11mm but for me I'm not looking for another 'project' dealing with the fabrication of a custom bracket to keep the existing switchgear or re-wiring to accept a different switch cluster."

The CNW adapter for their Brembo master cylinder simply bolts to the master cylinder and then you attach the OEM switchgear to it on the handlebar, just as you attach the OEM switchgear to the OEM master cylinder. No fabricating or futzing around required! :)

Yep, I'm aware of the adaptor bracket but this is on the CNW website:

  • The Lucas / Brembo bracket does not work on the Mk3 machines
I have MK3 switchgear:(
 

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Does anybody know the diameter of the pistons in the Brembo 4-piston caliper CNW use?
 
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Yep, I'm aware of the adaptor bracket but this is on the CNW website:

  • The Lucas / Brembo bracket does not work on the Mk3 machines
I have MK3 switchgear:(

Ah! Sorry, I failed to notice yours was a mark III! :(
 
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This might be more than you want to do, but here is how I kept my MK3 switchgear and fitted the full Madass kit. The full kit gives you a big disc ,six piston caliper, new custom fork leg and the correct MC for that brake.
It stops like a modern bike now.

http://www.accessnorton.com/new-front-brake-kit-t15950-45.html?hilit=madass brake

On edit-
Sorry, I see that thread is no longer available.
 
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