CNW Front DIsc Brake Upgrade

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If you want a cheaper way of having very good brakes do it the way I did.
I installed a 12mm Brembo master cylinder with my otherwise stock brake. This change in area of the master cylinder makes a huge difference and I wonder why it was not made this way in the first place. The change gives you about 36% more brake pressure with the same amount of effort from your hand. It is very powerful, it feels more like double than only 36%. Also the wooden feel of the brake is changed to a nice soft feel. I have never had any problem with it fading. I have ridden mountain passes two up with luggage with no brake fade. I ride fast, but I don't use the brakes that hard really. The master cylinder only cost about $120.00. I got an old brake lever, ground the lever perch off, filled it a bit with weld polished it, and now it makes a nice holder for the original Lucas switchgear. The switchgear fits in between the master cylinder and the grip. Now days most bikes are made with the master cylinder and the switch gear as two separate pieces.

Nigel
 
Tom Mellor road races his Triumph 750 Triple with a single disk brake. I think it is the standard iron disk and the Lockheed aluminum caliper. He uses a 12mm master cylinder. He says he doesn't need the second disk since it adds weight and he has no trouble racing with the single disk. He is one of the faster guys around here. I wonder why his brake doesn't fade? He stops repeatedly from 120 MPH.
 
Ditto on the racing with no fade. I raced a ‘73 Commando years ago with the standard front brake. Lousy brake, but never experienced fade. Never. Tried different pads but it was never a very effective brake. A Brembo master cylinder and a single modern floating disc would be wonderful – but better get a modern front tire and stiffer fork springs too.
 
John Mcdougall used to roadrace his Featherbed Atlas at Westwood with just the Commando two leader drum brake. He managed to set a record there once with that bike. I asked him how the brake was for roadracing - "Completely useless, it would just turn red hot, which looked great at night" was the answer. I guess some guys can go pretty fast with no brakes or not much brake, but for safety it might be one area that deserves to be designed with some reserve capacity. If you never use the reserve capacity, no matter. Fortunately there are now several options for the Commando. I agree that the most needed for a roadgoing Commando is a good big light single disc and then appropriate caliper and m/c. The lighter weight disc also gets rid of several pounds of rotating and unsprung mass, always a good thing.
From the photos I have seen of Tom Mellor's bike, it looks to be fitted with the Lockheed racing caliper setup.

Glen
 
I have the ground disc as shown, stock master cylinder sleeved, SS lines semi metalic pads.
Works very well so much better than stock. But I dont weigh much and I dont make time
like I once did. For general street work it serves nicely.
 
Onder said:
I have the ground disc as shown, stock master cylinder sleeved, SS lines semi metalic pads.
Works very well so much better than stock. But I dont weigh much and I dont make time
like I once did. For general street work it serves nicely.
Click to expand...

Where did you get the SS brake line?

I think I am going to get my Master Cylinder re-sleeved to 13mm, have my disc ground and get some Ferodo pads.
 
I too have Madass's front brake kit, which I fitted without issue. The kit is selling for US$750.00 plus shipping and is great value IMO. As has been said before the limiting factor becomes the front tyre's grip. I like the CNW kit of course, but (again IMO) it looks a bit bling/chopper, compared to the more sportsbike look of the Tokiko caliper and custom disc on Don's version. Don's version also allows you to keep the original switch block and throttle, includes the lower fender brace, and has a neater SS hydraulic line.

Don's online store also has a variety of other goodies, and he is very good to deal with.

http://www.tritonmotorcycleparts.com/29 ... line-store


PS> I'm in no way connected to Don, other than as a satisfied customer. :D
 
Here's what that brake looks like on a MK3. You can retain all of your MK3 swithgear and throtttle, however figure about six hours to fit on a MK3 vs maybe a couple of hours to fit to all earlier Commandos.
Price was 650? plus shipping for Forum members, not sure if that deal is still on.
I do agree with others that the stock brake can be made to work for about 99% of all conditions. It was that other 1% that nearly put me over a cliff and into the Fraser River!

Just had her out for run, I think it is finally at a point where it needs nothing but to be ridden.

Glen

CNW Front DIsc Brake Upgrade[/URL
 
worntorn said:
Here's what that brake looks like on a MK3. You can retain all of your MK3 swithgear and throtttle, however figure about six hours to fit on a MK3 vs maybe a couple of hours to fit to all earlier Commandos.
Price was 650? plus shipping for Forum members, not sure if that deal is still on.
I do agree with others that the stock brake can be made to work for about 99% of all conditions. It was that other 1% that nearly put me over a cliff and into the Fraser River!

Just had her out for run, I think it is finally at a point where it needs nothing but to be ridden.

Glen

CNW Front DIsc Brake Upgrade[/URL
Click to expand...



Most any of the high mountain passes will teach you the limits of the stock caliper and rotor pretty quickly if you ride at a sporting pace. Somewhere around switchback number 4 or 5 on the downhill side.....
And it definitely gets worse with the small bore master cylinder.

Guys that stick to the flatlands will likely never have a problem. Jim
 
In answer to the question about SS line source, I think it was from RGM.
 
"Those who stick to the flatlands"... Seriously, I thought that was against some law or code or just un-Nortonlike!!!
 
comnoz said:
Most any of the high mountain passes will teach you the limits of the stock caliper and rotor pretty quickly if you ride at a sporting pace. Somewhere around switchback number 4 or 5 on the downhill side.....
And it definitely gets worse with the small bore master cylinder.

Guys that stick to the flatlands will likely never have a problem. Jim
Click to expand...

Interesting that the small master cylinder that is seen by many as a great upgrade actually makes the situation worse. It makes sense though. The sleeved mastercylinder makes the brake feel better around town because it gives more brake pad pressure for a given handle squeeze. When in a situation requiring repeated hard braking, more than stock braking is initially available (why most rave about the sleeve) but more heat is also generated, meaning the fade point will come sooner. If you never push the brakes hard enough to hit the fade point, then the resleeve seems a cheap way to get a good front brake. Trouble is, you never know how close you are to no brake at all until it happens!

As you suggest Jim, it was the downhill switchbacks that caused my brake to lose it's grip on things. To be precise, it was downhill switchback number four on Duffy lake road that did it.

Glen
 
We do serious twisties around here and we have a few ex racers in the group so the pace is often quite "spirited" and, as I said I have never had an issue. My brakes are the stock front caliper, SS line, sticky Ferodo pads, and the CNW MC with Castrol Dot4. I also have a vented (cast iron) disc; perhaps that makes the difference. It was on the bike when I got it in '06 so I have no idea what brand it is. It's definitely a manufactured vented disc, not a stock disk with holes drilled in it. It looks really bad after sitting out in the rain but a bit of braking "wipes" the rust off1 So actually, the ONLY part of the stock brake system I have is the caliper! :)
 
One thing I believe is stuff posted by Comoz or Worntorn. I know both of you and trust your opinions. I think though that a lot of people will benefit from changing to a 12 or 13mm master cylinder. My bike has the standard caliper but is has a stainless rotor from a Yamaha and a 12mm Brembo master cylinder. The brake is excellent and it has never faded.

Worntorn knows I am not a flatlander and I usually do the Duffy Lake Road several times a year in both directions. Often after ascending to the top of the hill I go back down so I can do it again. I never had my brakes fade. I know I that I ride like a touring rider, but a fast one; I don't use my brakes that severely, but I do use them. Sometimes people behind me have asked if my brake light is working! I guess I don't brake that often. One time I got to the bottom of the hill at Duffy Lake quite a bit before my friend who was on his ZX12. He was complaining that his brake rotors had warped, I had descended ahead of him on the Norton and had not really done any aggressive braking at all. I guess if Glen was there he would have been a long way ahead of me, but usually hardly anyone is!

Maybe there is some other reason why the brakes are fading. Maybe you need to change your brake fluid? I use Dot 5. I know that Tom Mellor races his Trident with a single disk and a 12mm master cylinder. Obviously his brakes don't fade or he would have to alter them.

Maybe when I put my Norton back on the road I will do some experiments to see if I can get the brakes to fade.

Nigel
 
Hi Nigel
I know you cover a lot of ground in a hurry .

It took a lot to make my stock brake fade. The first time it occurred was when following Robert Watson's Vincent. Robert is a good rider (ex Westwood) and was intent on showing me that a Vincent is faster through the mountains than a Commando :mrgreen:
I wasn't about to let that happen and did not,but I have to admit that on hard repeated braking the Vincent had my Norton beat. His stock 1948 twin drum brakes did not suffer noticeable fade in the same steep downhill stretch where the Norton disc front brake went to zero. The interesting thing was the lack of warning. It went from good braking to near zero in a couple of seconds. I guess the pad surface reached a critical temp. Fluid wasn't the problem, there was no softness in the brake feel, it was still solid. When the fluid goes bad it boils and the lever or pedal goes to mush.

On the same trip we left Robert's son Jeff quite far behind on his modern Triumph Sprint 955i. Jeff hit some gravel early on and nearly went down. The old idiots up front paid no heed to such things!


The obvious answer is just to back off on speed a bit so that brakes are not much in use. As you say, one can travel very quickly with little or no braking on even some very twisty roads. A reduction of only a few MPH makes all the difference. I tend to do that nowadays, though once in awhile caution is thrown aside. For those occasions the Madass brake is pretty nice.

Glen
 
Whether you experience brake fade or not depends on several variables, not the least of which is riding style. If you belong to the Freddy Spencer school of smooth riding style, you aren't as hard on the brake pads as someone how charges into corners and brakes as hard as possible as late as possible every time. Brake fad is caused by getting the pad material too hot. It's that simple. The pad material breaks down into a vapor between pad and disc and seriously reduces friction. It should be obvious that brake pad choice is also a very significant factor. You're less likely to get fade with a stock Commando because you'd have to be a gorilla to squeeze hard enough to overheat the pads. Not saying it can't be done, but it's a lot harder. With the smaller master cylinder you get a lot more pressure at the pad, which generates more friction, which generates more heat. The disc design and material has some effect of fade, but way less than the pad material and pressure applied. With the stock pad material and a 12 mm m/c on a MK3 (admittedly the heaviest Commando), all it took on my bike was a series of really hard stops, and the brakes faded to almost nothing. They were fine again as soon as they cooled off. To be fair, that never really affected my riding. I'm not normally a really hard braker, and most of the twisties I regularly ride in seem to respond better to less braking and more keeping up corner speed. The point and squirt school of cornering doesn't seem to work that well for me anyhow. I've never tried the Ferodo pads in the stock caliper, and they might be a lot better. I used Ferodos a lot in the Lockheed racing calipers, and always liked them.

Loss of braking from boiling the fluid is a different animal, and I don't think that is what we are talking about here. High temp Dot 4 is my preference, but any good Dot 3 or 4 fluid should be fine, as long as it's fresh, or Dot 5 if you're a fan of it. The important thing with fluid is just to change it regularly.

When it's all said and done, I think most Commando riders on the forum, including me, would never have a problem with switching to a smaller m/c for more effective braking with the stock disk and caliper, at least during normal riding, particularly with high performance pads.

Back when I was still vintage racing, I saw a few Commandos with the stock caliper, but not many. Most switched to the Lockheed racing caliper, which has a much larger pad surface. Again, a lot depends on riding style. Unless the track has several high speed, hard braking corners in sequence, a smooth rider would probably never have a problem.

Can't use Tom Mellor as a comparison. His bike has the Triumph style caliper, which has the same larger pad area as the racing caliper. Can't really compare that to the stock Commando caliper.

FWIW, one of the best combinations of performance and feedback feel I've ever found was the original Norvil splined hub, cast iron 11.4" disc, Lockheed racing caliper, and Lockheed 1/2" m/c that came stock on my PR. The same combination, but with dual disks and 9/16" m/c worked really great too, but the extra unsprung weight was noticeable in the handling.

Ken

Ken
 
Well said, Ken.

Riding style has an awful lot to do with it and to add to what you say, a Commando does not respond well to the "point and shoot" or "square it off" cornering style that rewards peaky engined bikes. Heavy braking does not agree with high cornering speed and the latter is our bikes' strength. That's because we don't have a "top end" power band but a broad one where high cornering speeds compliment an even smooth application of power; feed it in and keep it on the edge of traction and while approaching the exit standing it back up onto the fat part of the rear tire, keeping the rise in power coupled to the rise in traction. As you say, the weakness of the brake appears on steep downhill switch backs where, by the nature of the corner, cornering speed is not rewarded but deceleration is. The quick repetition of those switch backs builds disc/caliper heat. Drillings help that layer of evaporating brake pad gas to escape.
 
On this occassion,(steep downhill switchbacks) brake pads from Vintage brake were in place, other than that all dead stock items including the shiny disc. The owner of Vintage brake promised the pads (Ferodo?) would make a huge positive change to the braking and that the braking would be "scary powerful" They may have been marginally better, but really didn't make a big difference from the Emgo pads that were in before.
As you say Ken, with stock MC I was probably squeezing pretty hard on that brake lever, can't really recall, but I did get accustomed to putting lots of pressure on that brake to get the job done.

Glen
 
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