Commando beginner
- Thread starter shelby
- Start date
- Status
Can't resist the urge to post a pic of my '70 fastback. I can confirm the drum is weak -especially with two up.
Just got a '74 850 with disk - haven't ridden it yet so I can't comment on the differences. With a second bike, I figure I won't be doing much two-up riding anymore. :lol:
Still holding out for a chrome fender to replace the chopped item currently on.
Alloy tank great for weight and long rides, not good for dents.
Just got a '74 850 with disk - haven't ridden it yet so I can't comment on the differences. With a second bike, I figure I won't be doing much two-up riding anymore. :lol:
Still holding out for a chrome fender to replace the chopped item currently on.
Alloy tank great for weight and long rides, not good for dents.
JimC said:
Just an FYI here. I spoke to Mat from CNW the other day, and they are offering a rear 4-piston Brembo set up for the MKIII and it will be the same in appearance to there front kit. A litle pricey for me right now but we'll see how much the x-mas bonus is this year. :wink:
- Joined
- Apr 7, 2004
- Messages
- 1,691
Poor Shelby, Says he likes Roadsters and all he gets is a flood of fastbacks.
A 25:1 will work great. I've got a 2 piston Gremica with a 12" floating disc and a 11mm m/c. Gives me a 27:1. Its a real stopper. Lots of feel, yet you can lock it up anytime. That's with a soft front tire, BTW. You will really like that Brembo setup. The most important part of the hydraulic brake is the ratio. The stock Norton disc setup is a sorry excuse for a front brake.
Ron L
VIP MEMBER
- Joined
- Feb 27, 2004
- Messages
- 3,240
I have a similar setup on the Interstate with a sleeved Lockheed master cylinder that works great.
Colin,
I think the 30/34 4-piston might be overkill for the rear, especially if it will be combined with a 300mm disc. My goal here is to reduce unsprung weight so I will use a late style Brembo 2-piston rear caliper with a Ducati rotor. This will be about an inch smaller in diameter than the stock Norton and quite a bit lighter.
As for the front fender, the early Commando chrome fender is the same as the N15CS except for the center bridge. Mike Partridge shows the N15 fender in his catalog. You could drill out the rivets of one of these and and rivet the Commando brace (to the inside).
If my assumption concerning the term "floating disk" is correct, I'm amazed someone got it to work.
In the Commando development phase that I was still there for, we were constrained by management not to go for a big offset between the disk and the spokes to accommodate a caliper with opposed pistons. I guess none of our gurus had seen the type of caliper which is nearly every car in the world - a single psiton working opposite a fixed pad with the caliper free to move on guide pins.
Our big problem was that the side force applied to the disk was centered about 2" from the circumference and the sliding part was anly about 3" from the center. The first attempt put dowel pins in the hub and reamed matching holes in the disk.
Maybe for the first 5 applications, it worked correctly. After that the tendency of the disk to tip from the offset force caused galling of the pins. With that, the disk would no longer slide and the caliper force bent it. Bear in mind, this is testing with the bike stopped, so there's no braking torque on the sliding mechanism.
Round two was even dumber. This time, the disk was splined and matching splines were machined into the aluminum (!) hub. If steel sliding on steel jammed up, you can imagine what steel sliding on aluminum would do. This turkey never made it out on the street. Differential expansion would have been a problem if the disk had heated up the hub enough to close the already tight precision tolerances.
At the time I left, the boffins were still scratching some part of their anatomy. The sad thing is, if we hadn't spent the money on the abortive change of "Image" (the dreaded green ball) we might have had enough development funds to do a decent brake set-up.
I was on the stand at the 1968 Motor Cycle Show and overheard two comments. The bikes on the stand were silver metallic with an orange seat cover and had the Green Ball logo. One person asked if the development had been funded by the Irish government, as the colors were those of the Irish national flag. A second one asked where was the switch for those green turn signals.
Norton suffered greatly from being a small company when it came to getting expert help from suppliers. We didn't make enough vehicles to be a worthwhile account for the suppliers to really get enthusiastic about us. As a result many systems were "home-grown" and we didn't have the expertise it takes.
I'm glad to see the innovative designs you guys in the enthusiast community are coming up with. We sure could've used you in 1968.
In the Commando development phase that I was still there for, we were constrained by management not to go for a big offset between the disk and the spokes to accommodate a caliper with opposed pistons. I guess none of our gurus had seen the type of caliper which is nearly every car in the world - a single psiton working opposite a fixed pad with the caliper free to move on guide pins.
Our big problem was that the side force applied to the disk was centered about 2" from the circumference and the sliding part was anly about 3" from the center. The first attempt put dowel pins in the hub and reamed matching holes in the disk.
Maybe for the first 5 applications, it worked correctly. After that the tendency of the disk to tip from the offset force caused galling of the pins. With that, the disk would no longer slide and the caliper force bent it. Bear in mind, this is testing with the bike stopped, so there's no braking torque on the sliding mechanism.
Round two was even dumber. This time, the disk was splined and matching splines were machined into the aluminum (!) hub. If steel sliding on steel jammed up, you can imagine what steel sliding on aluminum would do. This turkey never made it out on the street. Differential expansion would have been a problem if the disk had heated up the hub enough to close the already tight precision tolerances.
At the time I left, the boffins were still scratching some part of their anatomy. The sad thing is, if we hadn't spent the money on the abortive change of "Image" (the dreaded green ball) we might have had enough development funds to do a decent brake set-up.
I was on the stand at the 1968 Motor Cycle Show and overheard two comments. The bikes on the stand were silver metallic with an orange seat cover and had the Green Ball logo. One person asked if the development had been funded by the Irish government, as the colors were those of the Irish national flag. A second one asked where was the switch for those green turn signals.
Norton suffered greatly from being a small company when it came to getting expert help from suppliers. We didn't make enough vehicles to be a worthwhile account for the suppliers to really get enthusiastic about us. As a result many systems were "home-grown" and we didn't have the expertise it takes.
I'm glad to see the innovative designs you guys in the enthusiast community are coming up with. We sure could've used you in 1968.
- Joined
- Nov 10, 2006
- Messages
- 1,532
Nah Frank you've got it all wrong, those brakes were a very subtle early form of ABS designed to work well with the re-cycled garden hose tyres we used to use back then. You see Norton were way a head at the time with ABS, green tyres and a green logo, what more could a guy ask for. :wink:
Cash
Cash
- Joined
- Apr 15, 2004
- Messages
- 1,616
ludwig - Just wondering, what master cylinder geometry are you using on that bike?
I'm running a custom brake on my 750 as well, using a 4 piston caliper from a Honda CBR600F4, a 13 mm master cylinder (not radial) from an F2, and a Harley brake rotor. The rotor carrier and caliper mount were made by a friend who is handy with that sort of thing. Sorry, no photo available at the moment.
It's very much like RonL's brake except I'm not currently running a floating rotor. I just went with an OEM take-off rotor. The parts are all available dirt cheap from Honda and Harley owners who upgraded. I've been very pleased with it, so much so that I'm putting one on my 850.
Debby
I'm running a custom brake on my 750 as well, using a 4 piston caliper from a Honda CBR600F4, a 13 mm master cylinder (not radial) from an F2, and a Harley brake rotor. The rotor carrier and caliper mount were made by a friend who is handy with that sort of thing. Sorry, no photo available at the moment.
It's very much like RonL's brake except I'm not currently running a floating rotor. I just went with an OEM take-off rotor. The parts are all available dirt cheap from Honda and Harley owners who upgraded. I've been very pleased with it, so much so that I'm putting one on my 850.
Debby
- Status
