Ollie has checked more than 20 clutches from other bikes.
No one is a similar product.
Since last year 2 of his bikes are running with prototype clutches.
I will wait how it works..
The primary noise is much quieter.
We will see.
961 Clutch ?
- Thread starter Nikoli
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No one is a similar product.
Since last year 2 of his bikes are running with prototype clutches.
I will wait how it works..
The primary noise is much quieter.
We will see.
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Saw this on the NOC site. Wasn't 'members only' (pretty obvious, as I'm not!) so throwing it out here as I know it's a subject of interest to you lot. Apologies if I'm stepping on toes.... From the recent factory visit, one member observed:
'There was also what looked to me to be a new clutch on a primary drive gear that looked like a 961 gear in the engine assembly area, this was interesting as it seems strange to produce a new clutch if you are only making 40 of the bikes. Maybe a new variant of the commando might appear with some much needed technical tweeks.'
'There was also what looked to me to be a new clutch on a primary drive gear that looked like a 961 gear in the engine assembly area, this was interesting as it seems strange to produce a new clutch if you are only making 40 of the bikes. Maybe a new variant of the commando might appear with some much needed technical tweeks.'
Fast Eddie
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Oooh you tease you…!
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Oh.... and a bunch of frames for the 'New' Commando step thru
(With front and rear baskets, of course)
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BritTwit
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Fantastic!
I love a nice rumor, especially surrounding the 961.
I'll add a supercharger, and six speed gearbox w/ speed shifter to the rumor.
Fast Eddie
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Did any of you boys who went notice this new clutch ?
BLIGHTYBRIT/SF
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There were a small bunch of classic bikes we saw from a distance in another area , in the engine area there may of been mechanical bits here & there , saw gear box gears/shaft , could of been an employee doing work on his own machine?? Don’t believe a new clutch is being designed, TVS looking to future,not past I’m sure
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Hi All
I was the one who spotted the clutch and commented on the NOC webpage. Allways good to start rumours. It was certainly not the same as the clutch in mine ( unfortunatley I have had to look at mine too often) the clutch basket looked smaller in Diameter but the drive gear looked very similar. It may have been off a different type of engine, although all the parts I saw in the engine assembly area looked like 961 parts. I am certainly interested to see what Theil come up with if it helps to quiten down the primary drive. I have a very noisy one.
Fast Eddie
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It’s topics like this that intrigue me about Norton.
How many motorcycle clutches are out there? The science behind the design of a well functioning clutch and primary were laid down years, or decades ago. Why did Norton manage to make such a bad job of theirs ??
How many motorcycle clutches are out there? The science behind the design of a well functioning clutch and primary were laid down years, or decades ago. Why did Norton manage to make such a bad job of theirs ??
Straight cut gears & only four springs in the cush drive are the reason for noise.
Fast Eddie
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I know no better so will take your word for that.
But then the question is still why go with those design elements?
And why the other unaddressed failure modes in the clutch?
Clive
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Apart from the undowelled ring gear I think it is a basic design that does the job and no more; it is capable of doing the miles if assembled correctly with correctly manufactured springs. Yes its noisy but most have open pipes so its just another item on the 'wouldn't it be nice if' list below the things that are most likely to fail on you.
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Because its more Alton than CNW
The original desing spec for the ring gear to the primary gear was to use toughened Shoulder Bolts.Because its more Alton than CNW
These were to be a precision fit through the ring into a precision counter bore fit into the gear. This practise is quite common in many differant applications and not unique to the 961 especially in car engines (MCT was originaly a car engine desginer). The shank of the shoulder bolt would hold the rotation of both items through 'shear' force. This is ample for this purpose and doesn't require dowels. It was actualy suggested to use dowels very early on but was dropped before design went to paper began because it wasn't really required. I think from memory the shoulder bolt shank is 06mm ? Times this by six and is way more than is required.
The problems occure because:
1 - A large set of gears were produced with the counter bore on the wrong side and were put into production becasue thats all they had ! This meant that only the screw thread was holding the gears in place, not as per the design specified !
2 - Two types of Shoulder Bolt are available in the same dimensions. These are either 'soft' or 'toughened'
It is possible that the soft types may have been used, hence failure.
Straight Cut gears are noisy by nature. Helical cut gears are quiet.
Helical gears are used in nearly all road bike applications due exactly to noise.
Straight cut gears absorb less power and cost way less than helical gears, hence their use in racing applications.
Some Japanese manufacturers have actually developed a special unique straight cut gear profile to allow silent straight cut gears, but this is after their own design from years of research and financial backing and is propriaty to them not others. Everybody else has to use the standard profiles & modules that are available as the gear cutting standard. Accuarate gear cutting for hardened steels is VERY expensive.
If I recall, the primary gears when made in the UK were £400 each mainly due to the very high spec of gear profile that was specified from the original Kenny Dreer design. Bare in mind you have the crank primary gear meshing with the balancer intermediate gear meshing with the clutch primary gear.
MCT already had a huge task redesigning the Dreer prototype to suit production and take it to market. To completly redesign this part of the drive train was another monumental hill to climb.
BritTwit
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The genesis of the design problem occurred with Dreer's original concept.
He should have taken a hint from the Thaiumph Bonneville design.
Drive the balance shaft off the timing side, eliminate the intermediate primary gear all together.
Then, without the intermediate gear, move the mainshaft/gear cluster forward a few inches.
Redesign the gearbox with the shift drum behind the gear cluster.
Gear shift spring pawl and shaft below and behind clutch as God and the Queen intended.
Then put the swingarm pivot in the rear of the cases.
That will provide a longer swingarm with no change in wheelbase, better stability, lighter frame.
Now this would make a great Commando.
Oh, and a supercharger too.
He should have taken a hint from the Thaiumph Bonneville design.
Drive the balance shaft off the timing side, eliminate the intermediate primary gear all together.
Then, without the intermediate gear, move the mainshaft/gear cluster forward a few inches.
Redesign the gearbox with the shift drum behind the gear cluster.
Gear shift spring pawl and shaft below and behind clutch as God and the Queen intended.
Then put the swingarm pivot in the rear of the cases.
That will provide a longer swingarm with no change in wheelbase, better stability, lighter frame.
Now this would make a great Commando.
Oh, and a supercharger too.
I agree completely, in fact I even said to MCT at pre-production exactly what you have just said, but all the tooling would have had to change for the crank case, so they had to work with what they had
MCT also agreed that the balancer was in the wrong place.
"Thats what you got, manage it'' I think was thier remit from Norton
I'm trying to get a feel to see what serious interest is out there to see if this is something to pursue.If I may stray back to the original subject
Nikoli, how many orders would you need to make it viable ?
I haven't yet come to a quantity figure until I could gauge the response, and then I would have to complete is costing study.
Personally I think the £800each figure from Norton is very steep, and from my own experience Bikers don't like paying out money very easily.
So I need to look at a realistic target sale figure, and then see based on interest how many items we would require to be viable against tooling cost.
I was hoping that by now I would have had some proper data on quantity, but other than you, I haven't had much solid feed back.
Did you have a quantity in mind ?
cliffa
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As I'm not a dealer I would only need one for my own bike. Mine is a pretty early one which I think had billet machined baskets rather than the later cast jobbies. As I mentioned earlier in the thread there is a guy on facebook with an early bike too and the rivets had let go. He must have continued to ride is like that as the spring pockets have been very badly damaged. So I think there is a market for a better unit.
