Peter Williams 2015 ?

Superb - thank you!

I notice the video was uploaded in March 2015 and I wondered if you guys had seen it. I found it interesting, especially when PW mentioned the way the Monocoque Commando steered. I wonder how many guys have tried different offset fork yokes with the standard commando frame ?

acotrel said:

I notice the video was uploaded in March 2015 and I wondered if you guys had seen it. I found it interesting, especially when PW mentioned the way the Monocoque Commando steered. I wonder how many guys have tried different offset fork yokes with the standard commando frame ?

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I am not sure what the comparison is worth Alan!

The monococque used leading axle forks, and of course its own design of yokes, and would in any case would be so very different in terms of stiffness. Those yokes would have had to compensate for the leading axle geometry.

I visited Tony Smith in hs workshop in Brize Norton to buy an ex works style Luca Rita ignition and timing cover, in about '77. He was meticulously peparing a set of those works forks, which I understood were derived from AJS Motocross parts, but I never saw them fitted to any Commando he raced at that time.

I was looking at the factory race kit for the commando and there was an aluminium top yoke. It appeared to have a lot of offset which might have been needed with the 19 inch wheels. I read somewhere that the first Commandos flicked a few young guys up the road when they rode over the cats-eyes. Apparently the next model had slower steering. I wonder how many guys have altered the fork yokes when fitting 18 inch wheels ?
I'm always interested when top riders mention the way their bikes steer. That MV Evoluzione 500cc GP bike which Ago made available to the public has his own special design fork yokes. With my own bike, the most important improvement I've found is how to make it tighten it's line in corners. It means I can ride it a lot faster and turn under other much more powerful bikes.
With a standard commando frame the combination of quick steering with the isolastics might be a problem.

Brilliant link and thanks for posting- btw did anyone not smoke in 1973 ?

Back in the days when Phil Read raced the 650 production racer with Feather bed frame , it was found necessary to build front wheels with an offset
to get the thing to handle.. Culprit was though to be the changing weight distribution occasioned by alternator as opposed to magneto and dynamo.
Presumably the weight mass and extension of clutch on Commando primary drive must have a similar if not worse effect.. Has anyone experimented
with a rim offset to compensate... Many Commandos will not steer hands off in a straight line and this must be why.

If the wheels don't align, the handling can feel stiff.

oldmikew said:

Many Commandos will not steer hands off in a straight line and this must be why.

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Must it ?
Surely if some do steer hands off in a straight line, then the culprit lies elsewhere....

My old 850 was pretty good - with new shocks, steering bearings, swingarm bushes, new tyres and reset isolastics etc.
Until I read here that some weren't so good, I didn't know there was a problem.
850 was pretty strong willed in the steering dept, swerving around a rock on the road required look ahead action...

oldmikew said:

Back in the days when Phil Read raced the 650 production racer with Feather bed frame , it was found necessary to build front wheels with an offset
to get the thing to handle.. Culprit was though to be the changing weight distribution occasioned by alternator as opposed to magneto and dynamo.
Presumably the weight mass and extension of clutch on Commando primary drive must have a similar if not worse effect.. Has anyone experimented
with a rim offset to compensate... Many Commandos will not steer hands off in a straight line and this must be why.

Click to expand...

'Culprit' was not as stated.
The reason for the steering anomaly was the lacing of the wheels, which were such that the wheels could be adjusted to be parallel, but were not in alignment. Once cause was identified, re lacing the wheels corrected the problem. See my earlier post in the discussion 'The 650 Norton thread' started by beng

One thing which is difficult to pick up is whether the swing arm is twisted or the ends of the pivot are not equidistant from the centre of the steering head, due to a misalignment during the manufacture of the frame. As you compress the rear suspension, the rear wheel effectively moves sideways slightly.

acotrel said:

One thing which is difficult to pick up is whether the swing arm is twisted or the ends of the pivot are not equidistant from the centre of the steering head, due to a misalignment during the manufacture of the frame. As you compress the rear suspension, the rear wheel effectively moves sideways slightly.

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Yes that would be difficult to spot agreed.. Have owned mine from new , it handles and steers well enough for fast road riding , racing might be a different matter. If I take my hands off the bars and put on tank , it will drift to left , correctable by moving body weight . None of my other bikes do this . But there is a lot of revolving primary drive mass that is way off the central axis. Reading about Phil Reads experience in Classic Racer
was quite a shock-given the Feather Bed was a bench mark for steering and handling. Do not know if you ever saw Read race or ride but he is a superb natural rider. Remember seeing him demonstrate the then new Laverda Jota round a wet Brands Hatch . He was faster round Druids on a heavy bog standard Laverda than anyone racing on that particular day. So my inclination is to think it must have been quite a problem for him to have so remarked . Eventually , Sid Lawton who entered the bikes for the factory had front wheel made up with an offset. I think it was 3/16 . Wish I could find the article.

<<'Culprit' was not as stated.
The reason for the steering anomaly was the lacing of the wheels, which were such that the wheels could be adjusted to be parallel, but were not in alignment. Once cause was identified, re lacing the wheels corrected the problem. See my earlier post in the discussion 'The 650 Norton thread' started
>> Beng

So was the lacing changed on all Norton wheels by the factory or just on the production racer?

oldmikew said:

'Culprit' was not as stated.
The reason for the steering anomaly was the lacing of the wheels, which were such that the wheels could be adjusted to be parallel, but were not in alignment. Once cause was identified, re lacing the wheels corrected the problem. See my earlier post in the discussion 'The 650 Norton thread' started by beng

So was the lacing changed on all Norton wheels by the factory or just on the production racer?

Click to expand...

Could you post a link to the 650 Norton thread mentioned above? I tried searching for it in both Commando and Other Nortons, and had no luck. I'm curious to see what the discussion of offset wheels is all about.

As far as the PR front wheel, on mine, as it came from the factory, it was laced up centered on the original Campagnolo front hub, and the wheel was central between the forks. No offsets of any sort.

Ken

It would be possible to lace the front wheel with an offset and turn the rear to get alignment. If the problem was weight distribution, it might make more sense to lace both wheels up with the same amount of offset in the same direction, however it would be a bodge job. I cannot think how there would be that much weight difference from side to side of the bike. As far as the heavy crank is concerned, my bike turns extremely quickly on tight circuits and I have never felt any precession effect. What I have felt however, is the lag in the throttle response when using the standard gearbox with the wide ratios. It makes the bike almost impossible to ride smoothly. Of course the Seeley has the rigidly located swing arm, so it does not get the wanders. When I ride it, I can relax and let it do it's own thing, as long as I think well ahead and anticipate it's steering in corners. It really provokes an aggressive riding style. It is the offset on the fork yokes.

I think Rex and Cromie McCandless must have been very knowledgable when they made the first featherbed frame. If you look at the fork yokes on a manx, there is no way of reducing the offset , so they must have got it right almost first go. The manx steers and feels as though it slightly tightens it's line when powered if cranked over. I think that is where the feeling of confidence it gives to the rider, comes from. When we change the weight distribution as in a Triton, the steering often loses that feeling.

lcrken said:

As far as the PR front wheel, on mine, as it came from the factory, it was laced up centered on the original Campagnolo front hub, and the wheel was central between the forks. No offsets of any sort.

Ken

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I'm with you on this, Ken - as far as I'm concerned the centre of the front tyre's contact patch must be exactly halfway between the fork centrelines. Anything else is just going to cause an unwanted self-steering issue.

lcrken said:

oldmikew said:

'Culprit' was not as stated.
The reason for the steering anomaly was the lacing of the wheels, which were such that the wheels could be adjusted to be parallel, but were not in alignment. Once cause was identified, re lacing the wheels corrected the problem. See my earlier post in the discussion 'The 650 Norton thread' started by beng

So was the lacing changed on all Norton wheels by the factory or just on the production racer?

Click to expand...

Could you post a link to the 650 Norton thread mentioned above? I tried searching for it in both Commando and Other Nortons, and had no luck. I'm curious to see what the discussion of offset wheels is all about.

As far as the PR front wheel, on mine, as it came from the factory, it was laced up centered on the original Campagnolo front hub, and the wheel was central between the forks. No offsets of any sort.

Ken

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Ken ... my apologies my shit editing is to blame - the quote should be attributed to Beng -its his link not mine I did ask the question as to whether the lacing had been changed on all Norton wheels or just on the PR. The PR in question being the 650 SS entered by Sid Lawton from 62-64... Your wheel is off a Commando or a Featherbed?

i notice a post (oldmikew) refering to the Commando vastly overweight unbalanced gearbox breaking flywheel as a clutch......Mr Phil Irving in one of his books on restoring old classic(hah hah) motor cycles states that a gearbox mounted clutch should possess a few BASIC qualities some of which are that it should.......
1. NOT slip when fully engaged even when hot.
2. Free off INSTANTLY without drag whenever required even when hot.
3. Possess the LIGHTEST rotating weight reasonably possible.
4. Be EASILY operated by the rider.
The original 750 Commando clutch when employed DRY (as it was designed to be employed) possessed 1,2 and 4 but once oil entered the clutch 1 no longer applied either..or 2. As for the later models with their stronger diaphragm springs requiring more grunt to operate the clutch lever and their rediculously heavy bronze plates......
I remember the first time I operated the clutch lever on a new early 750.....I turned to the owner and said 'OK so who is the clever ****** who has disconnected the ******* clutch' to which he replied 'Funny but most people ask that question'. The owner then took us for a slow(hah hah but with that joke for a front brake it was not that fast) lap of 'The Island' and with the two of us NON lightweights on board the two finger easily operated clutch worked perfectly. I assume that later on oil would of entered the dry clutch resulting in slip every time the rider applied a bit of grunt to it.......but as my old Dommy manuals state on the problems page.....Problem..Clutch slip...Cause Oil on plates(usualyy caused by overfilling)..Remedy..Strip clutch and wash plates in petrol. A problem NOT helped by the brains in charge shoving the Commando oil level plug far too high up along with owners using the wrong grade and type of oil which is I guess why later manuals state 'Under no circumstances use more than 200cc of oil.......' but ONLY AFTER John Nelson took a good look inside a chain case to see exactly what was occuring........
Can someone remind me who the works mechanic was who forgot to do up the seat on the works Norton Commando that resulted in Mr Williams BIG off and ended his racing career?

oldmikew said:

lcrken said:

oldmikew said:

'Culprit' was not as stated.
The reason for the steering anomaly was the lacing of the wheels, which were such that the wheels could be adjusted to be parallel, but were not in alignment. Once cause was identified, re lacing the wheels corrected the problem. See my earlier post in the discussion 'The 650 Norton thread' started by beng

So was the lacing changed on all Norton wheels by the factory or just on the production racer?

Click to expand...

Could you post a link to the 650 Norton thread mentioned above? I tried searching for it in both Commando and Other Nortons, and had no luck. I'm curious to see what the discussion of offset wheels is all about.

As far as the PR front wheel, on mine, as it came from the factory, it was laced up centered on the original Campagnolo front hub, and the wheel was central between the forks. No offsets of any sort.

Ken

Click to expand...

Ken ... my apologies my shit editing is to blame - the quote should be attributed to Beng -its his link not mine I did ask the question as to whether the lacing had been changed on all Norton wheels or just on the PR. The PR in question being the 650 SS entered by Sid Lawton from 62-64... Your wheel is off a Commando or a Featherbed?

Click to expand...

Might be some other misunderstanding here on my part. When I hear Production Racer on the Commando forum, I assume it refers to the "Commando FIM 750 Production Class Racer" (AKA 750 Production Racer, Norvil Production Racer, Yellow Submarine, etc.) an optional model available for a couple of years from Norton. Since a 650 SS is not a Commando, you must be using the term production racer in the generic sense of a production bike that is raced, not a bike that is produced by the factory as a racer, and I missed that. Nothing wrong with that usage, I just assumed you were talking about the Commando PR. The wheel I was referring to is the one that came stock on the Commando Production Racer. FWIW, it is quite different from the rest of the Commando front wheels, using a different hub, alloy rims, and drilled for the Norvil racing disk.

I recall reading the discussion some time back about offset wheels in racing featherbeds on Ben's thread, but can't remember the details, and can't find the thread now. I was hoping someone would post a link to it so I could read it again.

Ken