Maney Belt Drive

Onder · Jul 10, 2019

The BNR clutch is very light and doesnt need much lift nor much effort to lift it. I only have 5k on it and I do wonder about the tiny ball bearings
in terms of lifespan. It is easy to install and work on.
It isnt cheap though.

cNw · Jul 10, 2019

swooshdave said:
My assumption was that most of the belt drive suppliers use an off the shelf front sprocket and then add the adapter for the Norton crankshaft. That’s certainly my impression of the RGM one.

The ones I have come across are all one piece, machined to fit the Norton crank. In other words, I believe they are made from scratch, machined for a specific belt design and with a Norton crank taper.

Matt

comnoz · Jul 10, 2019

swooshdave said:
My assumption was that most of the belt drive suppliers use an off the shelf front sprocket and then add the adapter for the Norton crankshaft. That’s certainly my impression of the RGM one.

That isn't the case with the RGM sprockets I have used.
One other plus. The RGM sprockets have steel shoulder plates instead of the short lived aluminum plates that some kits come with.

swooshdave · Jul 10, 2019

I know the RGM isn't and I was making an assumption about the others. If I had to make one I may look at off the shelf pulleys and then adapt one.

G81 Can Cycle · Jul 10, 2019

Stan Keyes has one of the CNW belt drive kits on his Formula 750 race bike. The bike dynos at 65 HP. Stan has run the belt drive for 3 1/2 years. NO CHANGE OF BELT, pulley, or clutch basket. Has almost 50 races, and over 200 practice sessions on it. The poly carbon belt still looks new, and no signs of wear of crank pulley or clutch basket

I have been running the same belt drive system on 2 CNW builds for 3 years with no problems.

Full disclosure, I designed and make the system for Matt, so I am sure there will be assumed bias LOL

o0norton0o · Jul 10, 2019

G81 Can Cycle said:
Stan Keyes has one of the CNW belt drive kits on his Formula 750 race bike. The bike dynos at 65 HP. Stan has run the belt drive for 3 1/2 years. NO CHANGE OF BELT, pulley, or clutch basket. Has almost 50 races, and over 200 practice sessions on it. The poly carbon belt still looks new, and no signs of wear of crank pulley or clutch basket

I have been running the same belt drive system on 2 CNW builds for 3 years with no problems.

Full disclosure, I designed and make the system for Matt, so I am sure there will be assumed bias LOL

I've been shopping belt drives and yours is on top of my wish list... Beautiful kit...

Fast Eddie · Jul 10, 2019

G81 Can Cycle said:
Stan Keyes has one of the CNW belt drive kits on his Formula 750 race bike. The bike dynos at 65 HP. Stan has run the belt drive for 3 1/2 years. NO CHANGE OF BELT, pulley, or clutch basket. Has almost 50 races, and over 200 practice sessions on it. The poly carbon belt still looks new, and no signs of wear of crank pulley or clutch basket

I have been running the same belt drive system on 2 CNW builds for 3 years with no problems.

Full disclosure, I designed and make the system for Matt, so I am sure there will be assumed bias LOL

Rumour has it that one will be being tested on a race spec 920 Maney motor sometime soon...

G81 Can Cycle · Jul 10, 2019

comnoz said:
I've not had issues with the button heads hitting the case. If it did I would just add some more shims on the shaft.

But there is no question, the RGM kit [like many RGM parts] may need more "fettling". But I will do that when I get double the belt life.

But if you want the best belt, it is going to be the Gates Polychain carbon that comes in the CNW starter kit. Some day I may have to make up some pulleys for that belt with the ratio I prefer for my bike.

Jim.
We looked into a larger front sprocket when we were building the NYC Seeley. We discussed this design with Gates and they did not offer a belt with the proper number of teeth for a larger front sprocket. This was about 3 years ago so maybe that has changed

G81 Can Cycle · Jul 10, 2019

Fast Eddie said:
Rumour has it that one will be being tested on a race spec 920 Maney motor sometime soon...

And, I wonder who would be building such a beast LOL

comnoz · Jul 10, 2019

G81 Can Cycle said:
Jim.
We looked into a larger front sprocket when we were building the NYC Seeley. We discussed this design with Gates and they did not offer a belt with the proper number of teeth for a larger front sprocket. This was about 3 years ago so maybe that has changed

Yeah, I am aware of that. It would take both front and rear sprockets and
re-positioning the trans to do it. That is why I have not done it.

I built a setup with the polychain belt and ran the same belt for several years on my 900cc racebike.

CanukNortonNut · Jul 10, 2019

I have run a Maney belt drive on my Interstate for some years now. The first original belt I pulled out when it finally went south this year after coming home from NY Sampson state Park get together. I had over 45500 miles on it . I think I'll change out my new belt at about the 30k mark . Run belts loose and make sure they track straight .
Cheers,
Tom

swooshdave · Jul 10, 2019

CanukNortonNut said:
I have run a Maney belt drive on my Interstate for some years now. The first original belt I pulled out when it finally went south this year after coming home from NY Sampson state Park get together. I had over 45500 miles on it . I think I'll change out my new belt at about the 30k mark . Run belts loose and make sure they track straight .
Cheers,
Tom

And what did the belt look like after 45k miles? (Which is a long weekend for Jim

).

Onder · Jul 11, 2019

How loose is loose ?

Fast Eddie · Jul 11, 2019

30-33mm free play (up and down movement) in centre of belt I believe.

CanukNortonNut · Jul 11, 2019

swooshdave said:
And what did the belt look like after 45k miles? (Which is a long weekend for Jim ).

The teeth were blown all laying at the bottom of the primary case. The outer carcass was still in on piece.

swooshdave · Jul 11, 2019

CanukNortonNut said:
The teeth were blown all laying at the bottom of the primary case. The outer carcass was still in on piece.

So there was a little slippage?

CanukNortonNut · Jul 11, 2019

Onder said:
How loose is loose ?

I usually turn the top run of the belt at the midpoint between the pulleys 90 degrees easily with two fingers and it should be about right on a cold bike. The belt should slide back and forth quite easily on the clutch hub . But check your adjustments and tracking on a running and warmed up bike .
Cheers
Tom

CanukNortonNut · Jul 11, 2019

swooshdave said:
So there was a little slippage?

Yes free wheeling you could say .

comnoz · Jul 11, 2019

Fast Eddie said:
30-33mm free play (up and down movement) in centre of belt I believe.

You have to keep in mind that the amount of play needed is going to be somewhat dependent on the condition of your sleeve gear bushings.

If the belt is pulled tight by the pull of the rear chain when everything is at operating temp then the belt is likely to fail. So if your sleeve gear bushings are loose then you will need more free play in the belt.

Just enough tension to keep the belt from climbing a tooth when kickstarting or jumping teeth when accelerating when the bike is cold -is just about right.

You always want to error on the too loose side -you will know when it's too loose with plenty of time to correct the problem.

But if it's too tight you will not know it until the first time you get it good and hot and the belt fails.

CanukNortonNut · Jul 11, 2019

Comnoz
Two thumbs up.

here.
T