front caliper behind the fork 74 then to the front 75

what was that about?

Yikes! You could be opening a can of worms here

Norton decided to try something different in 75

You will get answers, but this is a controversial subject because even Norton themselves never really answered the question completely. It had to do with a "possible" handling issue with the caliper on the right side behind the fork tube. No one really can answer why but the most plausible answer is the weight of the caliper and the mounting position back side front side of the fork tube.

There will be better answers I'm sure, and you can do a search on it and find a ton of info.

84ok said:

what was that about?

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Originally, with the brake on the right, some riders reported that the bike would pull to the left under braking, this doesn't appear to happen when the brake is moved to the left, and seems to be why the factory eventually moved the brake over to the left by swapping the fork sliders over, as the fork assemblies are the same for both left and right hand brakes.

disc-brake-from-left-right-side-t5611.html

Once upon a time, Noron built a motorcycle called the Commando, it was the fastest sweetest handling thing on the planet.

But it didn't brake too well.

So they installed a disc.

It then became an evil handling widow maker.

Then they swapped the disc over and all was well and it became an even sweeter handling machine than ever before.

And they lived happily ever after.

The End.

i guess discs were still ~ new on bikes at the time,

i remember mostly (if not all) single trailing setups at first then they found advantages going the other way,

then there was norton doing the opposite,

they got it right the first year then went totally against the grain the next

I've read the scope of reasoning why a single rotor on one side or the other and/or in front or behind slider has an effect on which way a cycle tends to drift hands off but think its mostly d/t the gravity down force thru stem angle hinge on mass of brake on one side pulling forks to turn to brake side, so RH brake allows forks to fall to R side which counter steers bike to L. I also think the LH power plant offset plus the extra LH mass of both chain drives is similar to using body english to lean cycle in direction of turn hands off. Published Experiments have shown the gryoscopic effects are too small to detect, so only acts over very short intervals of fork motion and then only if fork motion is jerked rather fast to create enough inertial reaction to be felt for an instant til fork turning motion stabilize.

Fast Eddie said:

Once upon a time, Noron built a motorcycle called the Commando, it was the fastest sweetest handling thing on the planet.

But it didn't brake too well.

So they installed a disc.

It then became an evil handling widow maker.

Then they swapped the disc over and all was well and it became an even sweeter handling machine than ever before.

And they lived happily ever after.

The End.

Click to expand...

Eddie,

It didn't brake too well with the disc either. I'm pretty sure the sweet handling bikes only existed for the magazine testers and in the minds of the marketing dept. Of course the works racers did handle but I don't think too many sweet handling bikes came out through the factory door. I'm not going to mention Whiskey Sierra Charlie,

hate to spoil your ending, Jose.

"Because it was better"

However is an sure if the caliper had been on the left originally and moved to the right the answer would still be

"Because it was better"

I could not see slinging the caliper on one side vs. another making a massive handling difference, but that's just me :roll:

What I could see making a difference is going to a properly sized caliper/master, and getting the chrome ground off the disc (and I don't mean half ground off due to questionable rotor wear).

I've spoken with a number those who were eager young Commando riders before the 850's who told me they could out sprint every cycle of early 70's in drags to the ton and better handling so a bench mark cycle in its prime at the time. Those who think perfectly true and strait make much difference has not pressed Commando in enough conditions-upsets to find out otherwise, even though all cycles ***should*** be blue printed for "best possible" handling out of what ever "innate design faults" exist. Spoke with a good number of riders who had '70's cycles like BMWs H2's etc onset hi speed wobbles in mere straight ahead freeway traffic so never rode them again but sold them off.

My SV650 with upgrade suspension at both ends and dual balanced front brake can out handle unlinked iso Cdo's 'safely' and allowed me to play sports bike games in twistes enough to require corner school to fully learn modern cycle quirks and limits of both V-twin and inline 4 type, so even straightest most rigid cycles scare the snot of me to point I'd rather just ride a lot more timidly but more comfortable easy if restrained control on my crooked ole wrong side brake Trixie Combat. interestingly my SV tends to creep up road crown for hands off L drift too,though maybe half a much as my factory Combat.

What's been found that keeps a cycle upright is the oscillation of forks, more apparent at slow speed or even stopped and this oscillation conitinues even at hi speed and can build up dramatically if there's slack in the frame and suspension and further aggravated if mass is not completely centered.
Review here what is known to keep bikes upright inline but still some mystery why they turn like they do. My testing reveals only thing I need to pay attention to is rear thrust angle and power, if not very much then forks help aim rear, if excessive forks are just along for the ride while trying to keep them from conflicting to much with the aim of rear patch. One the handling biggies I learned the hard way was those little jiggles and slight fight backs [of any cycle] going easy or on loose stuff - that seemingly completely disappears in sane fast riding range can suddenly show back up greatly magnified into positive feed back when the going gets tough, yIKES! Best wishes finding this out on your own. No more for me thankyou.
http://en.wikipedia.org/wiki/Bicycle_an ... e_dynamics

wow, googled this a bit to find the reasons for going with calipers behind the forks and stumbled on some interesting stuff

http://en.wikipedia.org/wiki/Douglas_%28motorcycles%29

In the 1920s Douglas built the first disc brakes, and had a Royal Warrant for the supply of motorcycles to the Princes, Albert and Henry

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Douglas gained significant attention in 1932–1933 when Robert Edison Fulton, Jr. became the first known man to circumnavigate the globe on a 6 hp Douglas twin fitted with automobile tyres. Fulton went on to write a book on his adventure titled "One Man Caravan".

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http://en.wikipedia.org/wiki/Robert_Edison_Fulton,_Jr.

Then, at age 23, he traveled 25,000 miles (from London to Tokyo in 18 months) on a twin-cylinder Douglas motorcycle, to study architecture around the world. Along the way he shot 40,000 feet of film of his travels, over the year and half period

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Jose Refit said:

Fast Eddie said:

Once upon a time, Noron built a motorcycle called the Commando, it was the fastest sweetest handling thing on the planet.

But it didn't brake too well.

So they installed a disc.

It then became an evil handling widow maker.

Then they swapped the disc over and all was well and it became an even sweeter handling machine than ever before.

And they lived happily ever after.

The End.

Click to expand...

Eddie,

It didn't brake too well with the disc either. I'm pretty sure the sweet handling bikes only existed for the magazine testers and in the minds of the marketing dept. Of course the works racers did handle but I don't think too many sweet handling bikes came out through the factory door. I'm not going to mention Whiskey Sierra Charlie,

hate to spoil your ending, Jose.

Click to expand...

actually it was pretty much the end of selling new commandos and in the end, going against the grain didn't work out, folks mostly weren't interested much anymore

the beauty though is the amazing support there is today, that puts to shame the support for other great machines of that era, or at least big time game changers and sellers of the time,

and then they lived happily ever after,

kinda turned out like this
http://www.bikeexif.com/norton-850-commando-2

“Seventies Japanese bikes are a dime-a-dozen in farmers’ fields across BC, Alberta and Saskatchewan,” says Brandt.

“British bikes are much tougher to come by, so they’re more expensive and less likely to be tinkered with. The ones you do see are usually restored to their original state.”

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As I 'd heard it here before on this forum in a different thread, in '75 they changed from a drum rear brake to a disc. The new rear disc was on the right hand side, so the front disc was moved to the left hand side thinking it would equal out the braking forces etc.and also improve sales, of course

cjandme said:

As I 'd heard it here before on this forum in a different thread, in '75 they changed from a drum rear brake to a disc. The new rear disc was on the right hand side, so the front disc was moved to the left hand side thinking it would equal out the braking forces etc.and also improve sales, of course

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Yup, that's what I think.
Sometime in 1974.... "Ah, Sir? I know you wish to introduce a rear disc brake for next year but it will have to be on the same side as the front disc. That OK?"
"No, no, no, that would look completely wrong, boy. Hmm, just switch the forks and stick that front disc on the left. Would you like some tea?" :mrgreen:

Yeah, that's the story I heard.

I also heard that when the disc first came out on the '72 Combat, Norton didn't want the feel to be too much different than the drum setup, except without the fade.

That's why the original Norton-Lockheed disc setup felt so wooden and hard - didn't want newbies to disc brakes grabbing a handful and flying over the handlebars.

The bike pulls to the left with the disc on the right; it doesn't with the disc on the left. I saw this first hand with a friend who changed it over. His '74 Commando pulled to the left (hands off - just as my '73 does) with the disc in the stock position. He moved it to the other side and it does not. I thought about changing mine but since I never ride with my hands off the bars…I decided it doesn't really matter.

I always assumed that it was because in 1975 they went to disc on the front and rear.

Since the sprocket is on the left side, that meant that they had to put the rear disk on the right side.
And..... that someone figured that they should offset the brakes to different sides of the bike.
Obviously that meant moving the front brake to the left side and that just swapping the fork legs around was a cost effective way of doing it.

The trade off being that the caliper was going to be on the front of the fork instead of the rear.
I'm probably wrong.......... it's just what "Assumed".

But when the Norton was new the front dics brakes worked a treat, I could lock mine up so easy, but they wore out as they got older and didn't work to well.
When I brought my Norton in 1976 I could have brought a new 75 model but the shop had one 74 left in stock and I brought that instead as it was a bit cheaper and lighter, but what I was told by the salesperson at the time was that they changed the front calipar on the 75 model because the pads gripped better facing the front of the forks, there was no mention about being on the same side as the rear disc if it was to stay that way of the 74 model, I didn't take much notice to what they were saying at the time, I knew which one I wanted and was so excited about my new Norton, I was only 17 years old and have only owned dirt bikes before that.
But you got to laught at what some saleperson will tell new potencial owners to try and sell a new bike to you, wheather it was to balance the front and rear brake, or for better grip on the dics or for looks, who knows the true reason, after 40 years we all know their limitations and some learned the hard way .

Ashley

That's why the original Norton-Lockheed disc setup felt so wooden and hard - didn't want newbies to disc brakes grabbing a handful and flying over the handlebars.

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These old crocks are a never ending series of upgrades and improvements (seemingly unavailable when they were new).
I've never owned a Norton with a stock disk so I have no baseline, but my `73 came with a drilled disk from Old Britt's and it works very well. Not sure if the master cylinder has been reworked since I've never checked. The drum on my `71 was pathetic and almost got me hurt once or twice. I suspect it needed a trip to Vintage Brake to make it work properly. I think I'll try the fork leg swap this winter.

http://en.wikipedia.org/wiki/Yamaha_XS_650

1976 models had the front brake caliper moved to the right fork leg, behind the fork as opposed to in front of the fork.

This placed the brake caliper nearer the axle center-line, requiring slightly less effort to steer.

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everyone was going that way, 'cept norton