Primary Belt Drive Pros and Cons?

carlo · Oct 11, 2011

Brooking,I'm in NY- 25 minutes from Niagara Falls in wine country, cad1023@roadrunner.com if you want to get a hold of me-

swooshdave · Oct 11, 2011

comnoz said:
Cons with the RGM drive are the clutch drum usually needs to have 20 or 30 thousanths removed from the outboard end of the splines so there is enough room between the circlip and the splines to allow the diaphram spring to go slightly concave and apply correct pressure to the pressure plate. If you make the clutch stack thicker so the diaphram spring does not need to go concave you will be rewarded with a heavier than necessary clutch pull and more clutch drag.

My RGM belt drive has an very light pull on the clutch lever but I have slip in the top gears when you really whack it. I was going to take a look at the stack height again, but would it be better just to skim the drum?

Hobot · Oct 11, 2011

Swoosh once ya do get the clutch to hold at hi speed whack ons, ya got to ask yourself, do I really want to accelerate that hard even faster? A good 750 is one of the few factory craft I'd used that gets more powerful pulling the faster ya go. For my own lession Swooh, how was the fit of the round spring in its slot, that is, did it have sloppy easy fitting in slot or had to press it in a bit. I've found when stack height just allows the spring to fit in slot w/o any effort or left over slack its as good as it gets in lever effort and holding full power in any gear. Maybe RGM key ingredient is their pressure plate too?

comnoz · Oct 11, 2011

swooshdave said:
comnoz said:

Cons with the RGM drive are the clutch drum usually needs to have 20 or 30 thousanths removed from the outboard end of the splines so there is enough room between the circlip and the splines to allow the diaphram spring to go slightly concave and apply correct pressure to the pressure plate. If you make the clutch stack thicker so the diaphram spring does not need to go concave you will be rewarded with a heavier than necessary clutch pull and more clutch drag.

Click to expand...

My RGM belt drive has an very light pull on the clutch lever but I have slip in the top gears when you really whack it. I was going to take a look at the stack height again, but would it be better just to skim the drum?

Yes, you are likely suffering from the diaphram not being able to go concave. Remove the .020 from the splines and I bet it will not slip again. Jim

cash · Oct 11, 2011

I reckon I must have been lucky, I think it was in 1994 I fitted an RGM belt on my Mk3 and it's never needed adjusting, never slips or drags and has a very light action

Cash

comnoz · Oct 11, 2011

cash said:
I reckon I must have been lucky, I think it was in 1994 I fitted an RGM belt on my Mk3 and it's never needed adjusting, never slips or drags and has a very light action

Cash

Maybe you should have bought a couple lottery tickets at the same time.

Actually some of them seem to work just fine. I have also seen some diaphram springs that were thinner than others which would solve the problem also. Jim

swooshdave · Oct 11, 2011

comnoz said:
swooshdave said:

comnoz said:

Cons with the RGM drive are the clutch drum usually needs to have 20 or 30 thousanths removed from the outboard end of the splines so there is enough room between the circlip and the splines to allow the diaphram spring to go slightly concave and apply correct pressure to the pressure plate. If you make the clutch stack thicker so the diaphram spring does not need to go concave you will be rewarded with a heavier than necessary clutch pull and more clutch drag.

Click to expand...

My RGM belt drive has an very light pull on the clutch lever but I have slip in the top gears when you really whack it. I was going to take a look at the stack height again, but would it be better just to skim the drum?

Click to expand...

Yes, you are likely suffering from the diaphram not being able to go concave. Remove the .020 from the splines and I bet it will not slip again. Jim

I'll take a look at it this winter. Thanks!

DogT · Oct 11, 2011

I have really enjoyed this thread, thanks everyone.

Dave
69S

Brooking 850 · Oct 12, 2011

I have also enjoyed this, as I wrote he intial post, looks like a RGM it is for me, hand carried from the UK to China, then on from there with me as none available in NZ (at this stage) unless you other Kiwi's on the forum know any different.
Thanks to all Mike

pete.v · Oct 12, 2011

Brooking 850 said:
I have also enjoyed this, as I wrote he intial post, looks like a RGM it is for me, hand carried from the UK to China, then on from there with me as none available in NZ (at this stage) unless you other Kiwi's on the forum know any different.
Thanks to all Mike

FWIW. This is the time to make sure the clutch center is up to snuff (not grooved) and to validate the clutch pack height. All will run well if these are given attention.

Brooking 850 · Oct 12, 2011

Ok thanks for the FWIW, will check all when I fit the RGM and keep you all posted, it might not be for a few months. Original clutch is behaving well at present.
Regards Mike

pipknight · Oct 12, 2011

hi Mike.
Bob Newby is the man on belt drives for Nortons. Have yet to fit one om my 850 Commando, but fitted one of his to my '500 Inter'' Norton, and its fantastic. No oil leaks,and is smooth as silk. Dead easy to fit, so should be the same on the Commando.
Regards
pipknight

Brooking 850 · Oct 12, 2011

Any links or contact details for Bob newby?
Regards Mike

Torontonian · Oct 12, 2011

So I have a new RGM kit already for the conversion this approaching winter. Sounds like I must change the gearbox sprocket as well to obtain the same gearing as present with my 21 tooth. So what should I change to , a 19 or say 20 to obtain similar gearing ratio ? Thanks ,Peter.

pete.v · Oct 12, 2011

Torontonian said:
So I have a new RGM kit already for the conversion this approaching winter. Sounds like I must change the gearbox sprocket as well to obtain the same gearing as present with my 21 tooth. So what should I change to , a 19 or say 20 to obtain similar gearing ratio ? Thanks ,Peter.

20T.
If you liked the 21T with the stock setup, You will love the 20t on the RGM.
72 mph at 4000 rpm. A very smooth cruise at 80. Nice pull down below. Very comfy 3rd round the town. Trust me.
Peter

Hobot · Oct 12, 2011

I can not recommend spending much time in lower gears as the sleeve bushes don't get lubes when spinning. A geared up C'do is a more pleasant useful C'do to me too. It allow using up 2nd gear bushes in hi rpm torque leaps to piss off the hot sports bikers.

Torontonian · Oct 12, 2011

20 tooth it shall be with no venting to outside ,enclosed.

Hobot · Oct 12, 2011

You will be happy as I have been with that combo.

pete.v · Oct 13, 2011

Torontonian said:
20 tooth it shall be with no venting to outside ,enclosed.

Good luck with that "no Venting" thing. I won't say it's not possible, just uncommon. You may want to keep an eye out for a donor cover.

bill · Oct 13, 2011

should NOT be an issue. I have 30,000 miles on mine, Florida summers, 650 mile days in summer heat, and a lot of just riding with NO troubles what so ever.

pvisseriii said:
Good luck with that "no Venting" thing. I won't say it's not possible, just uncommon. You may want to keep an eye out for a donor cover.

Primary Belt Drive Pros and Cons?

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