Wobble and Weave

phil yates said:

Here,

phil yates said:

Al
I tried to return your private message but for some reason it will not exit the outbox so I guess the best I can do is post it here.
Nothing personal in it of course. Sorry to others for no video and perhaps repeated views.

Click to expand...

Again, we're getting way off topic just to keep you in line.

Click to expand...

Then I am rightly chastised if my message to Al was off topic. I didn't think it was. It was about gyros and precession and left pulling bikes which is not wobbling and weaving I admit, but has received some attention under this thread.

I've learnt why my original Combat wobbled, and how Norton fixed it.
I've learnt nothing about weaving, but never experienced it anyway.
I'm happy with gripper's left pull fix theory (though I guess it should have been a separate thread).
Now I've learnt about forum outboxes!

All good information, even if the only issue answered conclusively was the wobble.
And the outbox. [/quote]

Phil,

don't worry about going off topic, it always happens, although we're still talking about handling so what's the problem? Found this link interesting too http://www.animations.physics.unsw.edu. ... precession especially if you scroll down to Precession. The upward force applied to the LHS of the axle, wheel spinning anti-clockwise viewed from left, turns the axle to the right. Upward force on the left is equivalent to a down ward force on the right (eg brake caliper albeit a very small force) so the axle turns to the right - not left. The diagram with force vectors also explains why counter steering works (I think). Gripper may have to spend another 8000 hours on a helicopter.

[
Phil,

don't worry about going off topic, it always happens, although we're still talking about handling so what's the problem? Found this link interesting too http://www.animations.physics.unsw.edu. ... precession especially if you scroll down to Precession. The upward force applied to the LHS of the axle, wheel spinning anti-clockwise viewed from left, turns the axle to the right. Upward force on the left is equivalent to a down ward force on the right (eg brake caliper albeit a very small force) so the axle turns to the right - not left. The diagram with force vectors also explains why counter steering works (I think). Gripper may have to spend another 8000 hours on a helicopter.[/quote]

Al
I'm sure most riders have better things to worry about than all this theory, and have long tired of it.
Like pete.v who has nightmares about MkIII's, let alone why they track so perfectly.
But it does interest me (MkIII owners have little else to worry or think about).

Firstly, thanks for the further info. The NSW Uni is 1.5 hrs drive from me so perhaps I should take a trip down there and get this sorted.
The web site deals with precession and upwards and downwards forces. With no outside forces involved, the wheel will precess left, as I read it, and less with increased rotation.

But if I understand your interpretation above, you are saying a downwards force on the right leg will cause the axle to turn to the right (when viewed facing left side of wheel). Okay, I can live with that. But we know that when axle is turned this was e.g. pulling right handle bar, wheel tilts and turns left. You may in fact be supporting grippers theory. It is important to understand that with a gyro (free wheel) turning the axle, or applying a force to try to, results in an opposite reaction of the wheel. Pull axle right, wheel will tilt left, and vice versa.

I'm not here to lecture anyone. I've got nearly double grippers flying hours but that makes me no expert on precession by any means.

If you think about it, when you lean into a left hand corner (for example), you are actually applying pressure on the right handle bar to initiate the turn. This is somewhat a sub conscious act. On Jap bikes with fat tyres, it is a lot more noticeable. A Norton just seems to go where you want to point it. One of the things I love about them. The steering is so precise, leaving most modern bikes for dead in my opinion.

I may have misinterpreted your above appraisal of what the web site is saying. And if so I apologise. But as I see it, correcting the left wheel pull is achieved with more weight (calliper) on the left leg.

The MkIII cured every problem ever known to a Commando rider.

Just to clarify something I said in the previous post. By initiating a left turn with pressure on the right handle bar, I mean a pressure pulling the right handle bar towards you.

Phil

phil yates said:

Just to clarify something I said in the previous post. By initiating a left turn with pressure on the right handle bar, I mean a pressure pulling the right handle bar towards you.

Phil

Click to expand...

With all steering issues resolved, i.e. left pulling, wobble and weave, and too many other improvements to mention,
it is not surprising that in 1975 the world motorcycle press labelled the MkIII "The Thinking Man's Norton Commando".

phil yates said:

phil yates said:

Just to clarify something I said in the previous post. By initiating a left turn with pressure on the right handle bar, I mean a pressure pulling the right handle bar towards you.

Phil

Click to expand...

With all steering issues resolved, i.e. left pulling, wobble and weave, and too many other improvements to mention,
it is not surprising that in 1975 the world motorcycle press labelled the MkIII "The Thinking Man's Norton Commando".

Click to expand...

I wouldn't make too many assumptions about Mk3's. My rear wheel centre line was nearly 1/4"approx. away from the frame centre line. Quality control and manufacturing tolerances were pretty poor in 1975.

With all steering issues resolved, i.e. left pulling, wobble and weave, and too many other improvements to mention,
it is not surprising that in 1975 the world motorcycle press labelled the MkIII "The Thinking Man's Norton Commando".[/quote]

I wouldn't make too many assumptions about Mk3's. My rear wheel centre line was nearly 1/4"approx. away from the frame centre line. Quality control and manufacturing tolerances were pretty poor in 1975.[/quote]

1975??
Try 1967 to 1975!!
The off set rear wheel was to stop the MkIII pulling left. So now we can start the discussion all over again.

Quality control and manufacturing tolerances plagued the Commando for its 8 year life. Probably the best 750 came just after they buried the Combat. The best 850 was/is the MkIII. But that is just my unbiased opinion.

Most Commando owners spent more time fixing them than riding them. There were exceptions, but not many.

The whole British motorcycle industry was in a state of (rapid) decline under the attack of Japanese atrocities, for want of a better word. It was a losing battle. But ask yourself this, in forty years time how many current Japanese Plastic Fantastics will still be alive, let alone revered and "treated like silkworms" by adoring owners. Not to mention adoring onlookers.

To me, the Commando is the epitome of English motorbikes but again my unbiased view. The isolastic suspension was revolutionary and it put the machine so far ahead of any other big twin, it wasn't even a competition.

It's just a shame they all fell apart so quickly :cry: :cry:

Al-otment said:

phil yates said:

phil yates said:

Just to clarify something I said in the previous post. By initiating a left turn with pressure on the right handle bar, I mean a pressure pulling the right handle bar towards you.

Phil

Click to expand...

With all steering issues resolved, i.e. left pulling, wobble and weave, and too many other improvements to mention,
it is not surprising that in 1975 the world motorcycle press labelled the MkIII "The Thinking Man's Norton Commando".

Click to expand...

I wouldn't make too many assumptions about Mk3's. My rear wheel centre line was nearly 1/4"approx. away from the frame centre line. Quality control and manufacturing tolerances were pretty poor in 1975.

Click to expand...

Thank you!

Much as I would not want one Triumph and BSA triples can contest with the ultimate vintage Brit Iron label. But not for long term reality. I got my SV650 and my nerve and good weather together at once today, first since late Nov. to remember ya don't have to steer forks to turn just lean on forks and bike towards where ya looking.

hobot said:

Much as I would not want one Triumph and BSA triples can contest with the ultimate vintage Brit Iron label. But not for long term reality. I got my SV650 and my nerve and good weather together at once today, first since late Nov. to remember ya don't have to steer forks to turn just lean on forks and bike towards where ya looking.

Click to expand...

I guess it depends on where you are looking and where you are wanting to go. Hopefully they are the same.
But yes Hobot, lean on left handle bar and you go left. Pull on right handlebar and you also go left. Same same.

But we never think about it do we? Unless riding single handed (eating your sandwich with the other).
Sub consciously we apply a force to the gyro up front via the handlebars. That force is in the opposite direction to the way we want to turn.

pete.v said:

Thank you!

Click to expand...

Thank me?
Well thank you.

It probably got mentioned earlier, I don't remember if it was. This has become a very long thread. But I seem to recall in the early days if your Commando weaved, the first thing to look at were the isolastics. Worn iso's in need of shimming could allow an oscillation of the rear wheel and hence weaving.

A lot of riders didn't know much at all about the isolastics, even less about how to shim them. By the time the vernier adjustment arrived on the MkIII, most riders knew a lot more about them and now they were so much easier to adjust. So perhaps a lot of weaving problems evaporated.

Interestingly, whilst the MkIII is regarded (by me……and pete.v) as being the most modern of Commandos, the vernier adjustment was not new. In the original Commando design, vernier adjustment was used for the isolastics. But it did not go into production due costs and we all ended up with shims until the arrival of the MkIII.

phil yates said:

Interestingly, whilst the MkIII is regarded (by me……and pete.v) as being the most modern of Commandos,

Click to expand...

Stop putting words in my mouth.

I might rather contend that if they hadn't put all their eggs in one basket and kept what was reasonabily tried and true, they might have been around a few more years. I know it's speculative rubbish but on the other hand, you might unknowingly be my best advocate at getting these bikes their own area. Keep it up the good work.

pete.v said:

phil yates said:

Interestingly, whilst the MkIII is regarded (by me……and pete.v) as being the most modern of Commandos,

Click to expand...

Stop that putting that shit in my mouth.

I might rather contend that if they hadn't put all their eggs in one basket and kept what was reasonabily tried and true, they might have been around a few more years. I know it's speculative rubbish but on the other hand, you might unknowingly be my best advocate at getting these bikes their own area. Keep it up the good work.

Click to expand...

Keep your shirt on young man.
"Interestingly, whilst the MkIII is regarded (by me……and pete.v) as being the most modern of Commandos,"
is precisely the truth.
You posted earlier referring to it as a modern ….dangy something.
I never said you liked it.

The MkIII did not bring about the end of the Commando. The rot set in in 72 when turn indicators were fitted. And the Combat motor nearly finished the company there and then. The kill switch should have been replaced with an eject button, to escape when you felt the engine erupting, which was more often than desirable.

I blame the Jap's. And I blame you guys for pouring the money in there in the first place, post war, otherwise they would be still making chop sticks only!

Blah blah blah

I do not believe any of you have experienced front wheel gryo expect that it make bike easier to stay up hands off at hwy speed. It take crash fast fork against front wheel gryo to push or pull on the inertia reaction but theres only an instant of it available and this tends to scare folks towards a steering damper which nulls any use out of gryo useful speeds. If the gryo was much an influence the MX air time guys or me could not flip fork side to side w/o it twisting bike on vertical or horizon CoG but it don't thank goodness. I stopped breaking bones and bike parts when I gave up on being the one to decide on fork aim to just lean and power bike down in direction needs and let forks road follow at they will, though with pilot assistance the fork turn helps bike lean faster easier than hands off body English. On THE Gravel bikes naturally straight steer into leans at all speeds but reverses the instant both tires hit pavement. I'm timid yet getting sea legs back to handle Gravel travel so even going 30+ish today a gust pushed rear over like 3" pretty as ya please but forks already natural facing that way so just a surprise drift at same slight lean angle instead of SPLAT, so fast to even know what went wrong to avoid it again.

LH SuVee tank has Gravel crunch from dogs but RH area has dark boot skid marks looking scrapes over the pure white paint, which finally hit me today that exactly what they are from a rodeo fling off of R boot out of the stirup. Think I'll glue tire tread over instead of bondo this time.

phil yates said:

With all steering issues resolved, i.e. left pulling, wobble and weave, and too many other improvements to mention,
it is not surprising that in 1975 the world motorcycle press labelled the MkIII "The Thinking Man's Norton Commando".

Click to expand...

I wouldn't make too many assumptions about Mk3's. My rear wheel centre line was nearly 1/4"approx. away from the frame centre line. Quality control and manufacturing tolerances were pretty poor in 1975.[/quote]

1975??
Try 1967 to 1975!!
The off set rear wheel was to stop the MkIII pulling left. So now we can start the discussion all over again.

Quality control and manufacturing tolerances plagued the Commando for its 8 year life. Probably the best 750 came just after they buried the Combat. The best 850 was/is the MkIII. But that is just my unbiased opinion.

Most Commando owners spent more time fixing them than riding them. There were exceptions, but not many.
The whole British motorcycle industry was in a state of (rapid) decline under the attack of Japanese atrocities, for want of a better word. It was a losing battle. But ask yourself this, in forty years time how many current Japanese Plastic Fantastics will still be alive, let alone revered and "treated like silkworms" by adoring owners. Not to mention adoring onlookers. :[/quote]

It is well known that Norton, in order to cut costs, out shopped their Commando frame making to Italy, where they apparently made such a bad job of them that they sent the Italian made frames to Reynolds to be checked over and corrected before being sent to the factory. Some frames must have slipped through.
Reynolds had the last laugh, when they charged them for this service, and the frames cost more than being made at the Reynolds tube factory.

Bernhard said:

phil yates said:

With all steering issues resolved, i.e. left pulling, wobble and weave, and too many other improvements to mention,
it is not surprising that in 1975 the world motorcycle press labelled the MkIII "The Thinking Man's Norton Commando".

Click to expand...

I wouldn't make too many assumptions about Mk3's. My rear wheel centre line was nearly 1/4"approx. away from the frame centre line. Quality control and manufacturing tolerances were pretty poor in 1975.

Click to expand...

1975??
Try 1967 to 1975!!
The off set rear wheel was to stop the MkIII pulling left. So now we can start the discussion all over again.

Quality control and manufacturing tolerances plagued the Commando for its 8 year life. Probably the best 750 came just after they buried the Combat. The best 850 was/is the MkIII. But that is just my unbiased opinion.

Most Commando owners spent more time fixing them than riding them. There were exceptions, but not many.
The whole British motorcycle industry was in a state of (rapid) decline under the attack of Japanese atrocities, for want of a better word. It was a losing battle. But ask yourself this, in forty years time how many current Japanese Plastic Fantastics will still be alive, let alone revered and "treated like silkworms" by adoring owners. Not to mention adoring onlookers. :[/quote]

It is well known that Norton, in order to cut costs, out shopped their Commando frame making to Italy, where they apparently made such a bad job of them that they sent the Italian made frames to Reynolds to be checked over and corrected before being sent to the factory. Some frames must have slipped through.
Reynolds had the last laugh, when they charged them for this service, and the frames cost more than being made at the Reynolds tube factory.[/quote]

I guess Bern that today, most of us that ride our Nortons have had a number of modifications done to the point where we are no longer comparing apples with apples. Electronic ignition, changed carburettors, replaced front brake, alloy wheels, steering dampers etc. Mine had the frame measurements properly checked out before rebuild, as have many.

So a lot of comments we might make now, may well have been invalid 40 odd years ago. The original Combat had very serious design faults (main bearings the biggest) but today you can build a beautiful very reliable one that goes and goes.

So which one is better than another today? There is not really any such thing. It is a matter of preference. I like my MkIII because of the electric start and some smaller variations to creature comforts. Changed brake pedal and gear levers positions? Means nothing to me, I am happy either way. That change was forced on Norton anyway. At least we got a hydraulic primary chain tensioner out of it, for what it is worth.

I like them all, they are all Norton Commandos to me. Many of the problems from 40 years ago have been sorted (by us) and now most of us can simply enjoy our machines. Rivalry between models is nothing but tongue in cheek to me.

Phil

Phil[/quote]

lot of comments we might make now, may well have been invalid 40 odd years ago. The original Combat had very serious design faults (main bearings thSo a e biggest) but today you can build a beautiful very reliable one that goes and goes.

And before pete.v tells me I am picking on the combat again.
By very serious design faults. I mean the motor was simply producing too much power for it's own good.
They stiffened the crank cases, but this seemed to exacerbate the problem, allowing the main bearings no flex to help accommodate the whip of the crank shaft. They cured the problem eventually, with the super blend bearings. They had countless warranty issues to resolve. They pulled combats off the production line and refitted them with de tuned engines, as best they could. It was a hugely expensive exercise which nearly put them out the back door, not to mention what effect it had on their reliability reputation. All this because at that time the American market (in particular) was demanding faster more powerful machines and the Japanese were accommodating this thirst. Standing quarter times were more important than how a bike handled for example. or so it seemed. Thus the Kawasaki MkIII was invented. What a shocker!! It should have been banned from any use on roads with a bend in them.

But Norton pulled through, only to find that by 1975 internal problems combined with aggressive Japanese competition simply overcame them.

Enthusiasts like us though, carry the marque on and in a manner never achievable in the 70's. They simply did not have our technology.

Phil