Using Norton calipers on both sides?
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speirmoor
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I looked in to it here a while back
http://www.accessnorton.com/dual-disc-brakes-commando-t12091.html
http://www.accessnorton.com/dual-disc-brakes-commando-t12091.html
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The gyro effect is pretty much irrelevant, however without it you would not be able to turn the bike. If you watch an on-board video which shows the handle bars, you would realise that when a bike is going down even the straightest road, it is always weaving - less at very high speed. There is a combination of steering geometry, gyro effect and weight distribution which makes some bikes handle better than others. Fitting lighter wheels to a bike does not necessarily make it handle better. Most of it is trial and error anyway.
Fast Eddie
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jimbo said:
Why not just do it like Triumph did on Slippery Sam?
One facing forwards and one facing backwards.
Simples.
jimbo said:
It's a desirable set-up. Someone needs to manufacture the oval section pinch bolt slider with the proper lug. It's a challenge which requires pressure casting, line boring and cnc machining. Cost vs. benefit? OR you could fit Norvil sliders, but then you have to dispense with the oem calipers.
If you're not a purist, there are other options, e.g., Maxton forks. Fitting used sliders off another brand (e.g., italian) will be cheaper and quicker.
-Knut
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The "mirrored" sliders exist (Norman White supplies them) but not the calipers.
johntickle said:
I gave Norman White a call a couple of years ago and inquired about the possibility of buying his custom sliders only. That he refused as I recall. His kit is 1860 GBP + VAT at the moment (ouch!). Pretty steep if you would like to fit different calipers and bigger rotors.
His present kit is unsightly also, using large adaptor plates to accomodate AP Lockheed calipers.
-Knut
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Yes, those Yamaha discs are also from a first generation design - thick discs and large diameter single pads. Very similar to the Norton design.
There's too much speed difference, at the pad/disc interface, between the point of the pad closest to the axle and the point of the pad at the outside of the disc. Pad much hotter at the Inside edge than at the outside edge. That's why the later generation designs went to narrow long pads with two or even three small diameter slave pistons - temperature equalization, speed of the disc across the pad more equalized.
Note too that axle diameter, over time, has increased. Now they are maybe twice that of the Norton and hollow. Lighter with more clamp across the wheel and less likely to twist in the forks.
There's too much speed difference, at the pad/disc interface, between the point of the pad closest to the axle and the point of the pad at the outside of the disc. Pad much hotter at the Inside edge than at the outside edge. That's why the later generation designs went to narrow long pads with two or even three small diameter slave pistons - temperature equalization, speed of the disc across the pad more equalized.
Note too that axle diameter, over time, has increased. Now they are maybe twice that of the Norton and hollow. Lighter with more clamp across the wheel and less likely to twist in the forks.
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Fast Eddie wrote:
"Why not just do it like Triumph did on Slippery Sam?
One facing forwards and one facing backwards.
Simples."
I am in the middle of doing that with my 1973 Triumph Trident. What is cool about the Triumph wheel is that the hub is already machined for a second disk, so you can just bolt it on. And yes, on the Triumph you can flip a stock slider around on the other side, mount a second caliper, and just hook up the plumbing.
Unfortunately, the stock Norton wheel won't accept a second disk. I don't know if the Norton triple trees are far enough apart to mount a second caliper on a flipped around slider. Anybody know??
Stephen Hill
"Why not just do it like Triumph did on Slippery Sam?
One facing forwards and one facing backwards.
Simples."
I am in the middle of doing that with my 1973 Triumph Trident. What is cool about the Triumph wheel is that the hub is already machined for a second disk, so you can just bolt it on. And yes, on the Triumph you can flip a stock slider around on the other side, mount a second caliper, and just hook up the plumbing.
Unfortunately, the stock Norton wheel won't accept a second disk. I don't know if the Norton triple trees are far enough apart to mount a second caliper on a flipped around slider. Anybody know??
Stephen Hill
o0norton0o
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I have a yamaha cast wheel and yamaha disc on my commando forks with a commando axle. I changed the bearings in the yamaha hub so the norton axle and yamaha hub would be compatible.
There were a few things that were different that I had to address with the yamaha disc.
1) less offset than the commando disc, so I had to shim the disc about .125" to be centered in the caliper after the custom made spacers were made to center the wheel in the forks.
2) bigger diameter disc. Stock Commando was 10.5" disc and the yamaha was 11.5" disc.
3) the bevel of the yamaha disc frame ran into the body of the caliper, so cutting the disc down to 10.5 diameter didn't solve the problem. I had to make an offset bracket and use a full sized disc instead
4) The '82 yamaha disc was slightly thinner than the norton disc. *(and probably half the weight due to the relief in it's frame...)
Now that I look at it, I realize that as much as I like the look of the lockheed caliper, I could have used a lighter weight brembo caliper instead of paying the machinist $350 for the offset bracket I designed which he made. The brake in the picture with the yamaha disc works much better than the stock brake I had previously. Some here have said that's a function of the added 1" diameter of the disc. I'm not sure if that's why, but it is noticably better, and only takes 2 fingers to brake aggressively.
I don't pretend to be an expert on motorcycle stuff, but I am into physics. It seems to me that If I can lock the wheel up with the single disc easily then having more braking power with a second disc isn't going to allow me to brake any harder than the single brake because both brake configurations exceed the tire's gripping potential.... right??
Which brings me to the question, Why would you want to add the weight of another lockheed caliper and disc to the unsprung weight of the wheel? Wouldn't it be better to get a single sided, lightweight, high tech, modern disc and caliper to save weight AND get better braking power?
There were a few things that were different that I had to address with the yamaha disc.
1) less offset than the commando disc, so I had to shim the disc about .125" to be centered in the caliper after the custom made spacers were made to center the wheel in the forks.
2) bigger diameter disc. Stock Commando was 10.5" disc and the yamaha was 11.5" disc.
3) the bevel of the yamaha disc frame ran into the body of the caliper, so cutting the disc down to 10.5 diameter didn't solve the problem. I had to make an offset bracket and use a full sized disc instead
4) The '82 yamaha disc was slightly thinner than the norton disc. *(and probably half the weight due to the relief in it's frame...)
Now that I look at it, I realize that as much as I like the look of the lockheed caliper, I could have used a lighter weight brembo caliper instead of paying the machinist $350 for the offset bracket I designed which he made. The brake in the picture with the yamaha disc works much better than the stock brake I had previously. Some here have said that's a function of the added 1" diameter of the disc. I'm not sure if that's why, but it is noticably better, and only takes 2 fingers to brake aggressively.
I don't pretend to be an expert on motorcycle stuff, but I am into physics. It seems to me that If I can lock the wheel up with the single disc easily then having more braking power with a second disc isn't going to allow me to brake any harder than the single brake because both brake configurations exceed the tire's gripping potential.... right??
Which brings me to the question, Why would you want to add the weight of another lockheed caliper and disc to the unsprung weight of the wheel? Wouldn't it be better to get a single sided, lightweight, high tech, modern disc and caliper to save weight AND get better braking power?
jimbo
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looks like you did it up right, however I did find that the pads available for the Norton caliper do not play well with the Japanese steel discs. I found a EBC floating disc to mount on mine that is thicker( you don't want your pads to fall out when worn) and does not score nearly as bad.
I just thought a dual disc front end with the factory calipers done up right with the calipers mounted behind the forks would be sweet. Its not gonna be a racey tech thing but a nice street setup
I just thought a dual disc front end with the factory calipers done up right with the calipers mounted behind the forks would be sweet. Its not gonna be a racey tech thing but a nice street setup
Fast Eddie
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o0Norton0o,
Ref your statement "It seems to me that If I can lock the wheel up with the single disc easily then having more braking power with a second disc isn't going to allow me to brake any harder than the single brake because both brake configurations exceed the tire's gripping potential.... right??"
In a word, no, this isn't right.
If you think about it, you can lock the wheel up on a bicycle, but this doesn't mean those same cable operated brake blocks rubbing on the rim would work on a Norton!
Even the stock Norton TLS front brake will lock the wheel up if yanked hard enough, but this doesn't make it a good brake.
A good brake needs to be progressive and have feel AND have power. This progressiveness happens very quickly, but it is enough to allow the front wheel to be correctly 'loaded', the forks to compress and the tyre contact patch to spread. When all this has happened, only then can maximum braking power be used without locking the wheel.
A good brake also needs to apply that power without you having to have a vice like grip on the bars (thereby effecting your control of the bike).
It seems counter intuitive I know, but the ability to lock up the wheel is NOT a positive reflection about the quality of braking provided.
Ref your statement "It seems to me that If I can lock the wheel up with the single disc easily then having more braking power with a second disc isn't going to allow me to brake any harder than the single brake because both brake configurations exceed the tire's gripping potential.... right??"
In a word, no, this isn't right.
If you think about it, you can lock the wheel up on a bicycle, but this doesn't mean those same cable operated brake blocks rubbing on the rim would work on a Norton!
Even the stock Norton TLS front brake will lock the wheel up if yanked hard enough, but this doesn't make it a good brake.
A good brake needs to be progressive and have feel AND have power. This progressiveness happens very quickly, but it is enough to allow the front wheel to be correctly 'loaded', the forks to compress and the tyre contact patch to spread. When all this has happened, only then can maximum braking power be used without locking the wheel.
A good brake also needs to apply that power without you having to have a vice like grip on the bars (thereby effecting your control of the bike).
It seems counter intuitive I know, but the ability to lock up the wheel is NOT a positive reflection about the quality of braking provided.
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