Another wobbling clutch basket.

htown16 · Dec 13, 2021

Decided not to hijack Berts thread so started a new one. I've got the same concern on a 73 I'm putting back together. Everything in the primary is assembled including the stator and rotor. I checked the alignment of the sprockets without the chain on and they were good. When I rotate the engine with the bike in gear using the rear wheel (normal riding mode) there is no appreciable wobble and the chain tracks straight. However, when I pull the clutch lever in(shifting mode) and rotate the rear wheel the clutch basket has some wobble. I'm thinking that if the mainshaft were bent it would wobble in both cases. Is it down to the large clutch ball bearing wobbling when it has no load on when the clutch lever is pulled in?

Schwany · Dec 13, 2021

I know nothing, but I have a feeling this is not that unusual when the clutch basket is not being pulled on and spun at higher speed by the primary gear on the end of the crank. Did you test the theory using the motor to spin the clutch, rather than using the rear wheel to spin the clutch?

BERT · Dec 13, 2021

htown16 said:
Decided not to hijack Berts thread so started a new one. I've got the same concern on a 73 I'm putting back together. Everything in the primary is assembled including the stator and rotor. I checked the alignment of the sprockets without the chain on and they were good. When I rotate the engine with the bike in gear using the rear wheel (normal riding mode) there is no appreciable wobble and the chain tracks straight. However, when I pull the clutch lever in(shifting mode) and rotate the rear wheel the clutch basket has some wobble. I'm thinking that if the mainshaft were bent it would wobble in both cases. Is it down to the large clutch ball bearing wobbling when it has no load on when the clutch lever is pulled in?

I think that when the clutch is engaged (clutch lever out)the assembly acts as a somewhat solid unit, and with a straight mainshaft and the bearing seated properly in both the basket and center and both shafts parallel there shouldn't be much wobble. When it is disengaged (clutch lever in)the basket is separated and can spin free on its roller bearing with the crankshaft via the primary chain so I would think it could easily wobble around. I am also trying to get this assembly sorted out . Thank goodness for this forum for the experienced insight.

cliffa · Dec 13, 2021

I agree with BERT. Clutch in normal position it's all locked together and if the shaft is running true the clutch centre and plates will hold the whole plot as one and also run true. Pull in the clutch lever and the basket is a free agent and will just wobble around on the feeble single row centre bearing. They are cheap to replace, but make sure you get a deep groove version and personally I would not bother with a C3 spec. That area has no large temperature differential so a (good quality) normal tolerance bearing should be fine in my opinion.

L.A.B. · Dec 13, 2021

cliffa said:
I would not bother with a C3 spec. That area has no large temperature differential so a (good quality) normal tolerance bearing should be fine in my opinion.

One dot or C2 (less than normal) clearance.

SteveA · Dec 14, 2021

I talked about clutch drum wobble with Norman White, because I have one of his belt drives. He said 'you need to worry if it doesn't wobble'. He says you need some movement in the bearing.

I changed the bearing anyway, due to a 'gritty' feel when rotating it, using a bearing supplied by Norman. Reduced the wobble a little, but it still wobbles, but with no 'grittiness' in the bearing.

concours · Dec 14, 2021

...and, sometimes I feel a low frequency/high amplitude vibration in the left footrest. Disengaging the clutch for a second allows another random clamp of the stack, sometimes less offset/out of balance.
A design with some flaws, but it works ok.

JMWO

Derek Wilson · Dec 14, 2021

I have noticed that the basket only wobbles if you take the primary cover off - so I leave mine on as much as possible -

jbruney · Dec 14, 2021

I believe Derek has hit the nail on the head squarely.... It used to concern me when I had it apart but it just keeps on running well, so in agreement on keeping the cover on to reduce wobble helped me get over it.

cliffa · Dec 14, 2021

The clutch on my 961 also wobbles. I suppose this was a deliberate "Heritage" design feature

BERT · Dec 14, 2021

I guess everything is good as long as the wheels don't wobble

Derek Wilson · Dec 14, 2021

BERT said:
I guess everything is good as long as the wheels don't wobble

And I can help you with that if need be

jbruney · Dec 14, 2021

The wobble is designed into them to clear the clutch plates of excess oil and to increase the life of well grooved clutch centers...... Maybe?

gortnipper · Dec 14, 2021

jbruney said:
The wobble is designed into them to clear the clutch plates of excess oil and to increase the life of well grooved clutch centers...... Maybe?

Or, [clutch baskets] wobble, but they don't fall down.

htown16 · Dec 30, 2021

To close this thread out, it was a severly bent mainshaft. Discussion of that is in a new thread "Bent Mainshaft"

74ok · Jan 1, 2022

htown16 said:
To close this thread out, it was a severly bent mainshaft. Discussion of that is in a new thread "Bent Mainshaft"

bent mainshaft

Looks like I have a bent mainshaft. Starting to pull things apart. Want to leave the gearbox in the bike. Shoud I dismantle the gearbox first or the primary. Will I need to maintain the primary intact to keep things from spinning when I do the gear box?

www.accessnorton.com

Another wobbling clutch basket.

htown16

Schwany

BERT

cliffa

L.A.B.

Moderator

SteveA

concours

Derek Wilson

jbruney

cliffa

BERT

Derek Wilson

jbruney

gortnipper

htown16

74ok

bent mainshaft

Similar threads