There seem to be....

Hiya guys,

There seem to be more belt drives than I can wave a stick at these days, have you any recommendations? I'm not looking for anything particularly outlandish, just good solid engineering, and with a long service life.

I'm in the uk btw.

Cheers all.

Hegel said:

Hiya guys,

There seem to be more belt drives than I can wave a stick at these days, have you any recommendations? I'm not looking for anything particularly outlandish, just good solid engineering, and with a long service life.

I'm in the uk btw.

Cheers all.

Click to expand...

I'm using an RGM one - no problems at all.

+1 on RGM belt kit.

The belts are (white type) of better quality than those of the Norvil (black type) which are more prone to being damaged by oil that may leak from engine or gearbox though main shaft.

RGM is probably the most affordable but I was impressed by the Maney system for the same price.

http://www.rgmnorton.co.uk/buy/belt-dri ... k3_797.htm

£259.00 EXCL. VAT



http://www.stevemaney.com/products.html

Belt drive (road) … £259.00

I just finished installing a Bob Newby kit on the 650SS. Quality is very good, almost too nice to hide under a primary cover.
Can't comment on longevity though there are lots of his belt drives out there and the overwhelming opinion is positive.
His belt drives and clutches seem to be used on a great many racebikes, perhaps that is because he is a Racer and race tuner.
I think his stuff might be a touch more expensive than some of the other options.
£425 for the Dommie kit including complete clutch.
I am glad to get rid of the slipping Dommie clutch and Domie oil leaks from the tin cover, however the Commando clutch once properly shimmed is wonderful and the cast alloy primary is oil tight, so it will remain a chain drive.


Glen

How much is a Newby Commando kit?

Pretty sure ol' Steve Maney knows a thing or two about racing too...

I believe the Newby Commando kit is similar in price to his Dommie kit. As near as I can tell from his website, his Commando kit does not reuse the Commando clutch, instead it comes with his own lightweight dry clutch. This is a very smooth clutch.

I suppose Bob Newby's products are on so many racers because of their ultra lightweight and durability. They seem to really take a beating. He is also quite happy to make up a one off system for a race. or road bike. He made one of these for my Vincent project bike. In order to withstand the torque, he used special thin friction plates which allowed fitment of 7 friction plates in a 40 mm setup, rather than his standard 5 pack 40mm , custom
high ratio to reduce trans torque load while giving me the higher overall gearing I wanted, and a custom length double toothed German made belt which runs the alternator from the outside top face of the belt. He did charge about £175 extra for all of that, but he provided exactly what I requested and needed.
I imagine that kind of flexibility in design is rather useful with the racer crowd.
For a standard or mostly standard Commando the design which utilise the Commando clutch are more economical and seem to do the job very well.
Glen

See the post below re belt versus chain.

Hegel said:

Hiya guys,

There seem to be more belt drives than I can wave a stick at these days, have you any recommendations? I'm not looking for anything particularly outlandish, just good solid engineering, and with a long service life.

I'm in the uk btw.

Cheers all.

Click to expand...

I have the RGM unit and it is fine. Although some will argue the point, I have experienced heat expansion of the hub to a point where I adjust the belt a bit looser that suggested.

When it starts to swell and the belt gets tight, the clutch will start to go away. I had it so loose that when kick starting it would jump a tooth or two over the crank sprocket. I brought it in just so it would not jump teeth and that seemed to be just right.

I have gathered that the Maney drive is less susceptible to this heat expansion and might be worth considering.

The other issue is the relative high gearing ( 1.964:1) of the RGM unit although it may be adjusted by changing the crank hub but I have not seen a 27, 26 or 25 tooth hub available. Otherwise the front drive sprocket offers some adjustment. With 20T sprocket 4000 was 70mph, 4500 was 80mph and 5000 was 90 mph, give or take 1 mph. 4100 in third was around 55mph.

I now have a 19t on and early observation shows roughly 70mph at 4500rpm. This is not confirmed because I am having tach issues right now.

I cannot say what the Maney drive ratio is but it seems the clutch hub has more than 55 teeth. This is another consideration.

I must admit, I have often thought about upgrading, that's if it can be classed as an upgrade?, to a belt primary drive, but have always found it so confusing with all the different makes on the market, and always so many tales of belts shredding and alloy clutch drums going all wonky!.

However, thinking of all the weight that the primary transmission puts on to the gearbox mainshaft, hanging out there in thin air, I really do like the idea of a lighter primary drive, so have been thinking again on going to a belt primary drive.

I like the sound of the Maney belt drive, he does have a very good reputation for building reliable parts, also his outrigger bearing has to be a really good upgrade.

I sent Steve Maney an email the other day, a couple of questions on his system, he replied that fitting his belt drive will have the same effect as running a one tooth larger gearbox final drive sprocket, ie the gearing will be slightly taller, and an expected belt life of 20 to 30 thousand miles, which would be good enough for me!.

It is a bit of money though, belt drive and outrigger bearing, which would also require the inner primary chaincase to be cut open, to allow fitting of the outrigger bearing, but does seem to me to be a very good modification, has anyone on here fitted both of the above?, would love to here how they fare long term,

John

There are a number of members here who have fitted the Maney outrigger. However you don't have to fit one to have a belt drive unit. If in doubt call Steve Maney and ask him about it. One of the reasons I would gladly spend money there again is because of the honest answer I got to that question.

Russ

IMHO this is a good thing NOT a bad thing If you look at the mechanics of it. the higher primary ratio is easier on the input of the gear box and the smaller countershaft sprocket is easier on the output side. so can you explain just why you think this is a bad thing.

pete.v said:

The other issue is the relative high gearing ( 1.964:1) of the RGM unit although it may be adjusted by changing the crank hub but I have not seen a 27, 26 or 25 tooth hub available. Otherwise the front drive sprocket offers some adjustment. With 20T sprocket 4000 was 70mph, 4500 was 80mph and 5000 was 90 mph, give or take 1 mph. 4100 in third was around 55mph.

Click to expand...

Using an RGM and its good - but beware - the clutch centre inner face can rub on the alloy hub face when hot and that causes clutch grab. Press the centre in by hand firmly and keeping force on it, try to rotate the two. It should be absolutely free. If there is the slightest resistance, it will get very bad as soon as the hub heats up. The solution is to provide more clearance by skimming 020" to 030" off the centre's inner face. I also replaced the hub bearing with something that actually had a bearing ID just as a pre-caution!
Also aligning the clutch pulley to the engine pulley is critical, the Synchroflex belt will shred its sides very rapidly if not set up accurately and fastened firmly.
See threads in the forum for details.

The normal Maney drive has 36 front teeth and 72 clutch teeth so 2:1. Hot belt drives should still allow the belt run to twist about 90' and still be able to work on/off from the side w/o touching the tranny adjustors. Touchy skillful setting as already detailed once everything as stable as possible. Most vunerable part of belts are their sides which can unraveal from grit inhaled or resisting by front side plate from walking til running off pulley. A dry clutch AMC box is a extra layer icing of smoothness plus some extra spunk in the get go. So I've asked myself, how lucky do I feel punk, was there six shots or 5, to have something in the chamber that my belt blow off, till lessons earned. If just wanting legal-ish joy rides and some freeway sections why bother, put the money in best chains and tires and shocks.

The RGM kit I use on my Commando engine is the one I used on my 600 Dominator. It's OK and trouble-free after some 5000 miles.

But I think the Newby is of better quality and smoother due to the use of several springs vs the diaphgram- Commando type of the RGM, which induces a sort of ON-OFF effect when releasing the lever.

L.

laurentdom said:

The RGM kit I use on my Commando engine is the one I used on my 600 Dominator. It's OK and trouble-free after some 5000 miles.

But I think the Newby is of better quality and smoother due to the use of several springs vs the diaphgram- Commando type of the RGM, which induces a sort of ON-OFF effect when releasing the lever.

L.

Click to expand...

Something is not right with your diaphragm setup.

Hi, is there a cush drive in the Newby clutch....?

The Newby belt drive does not have a cush included. Here is the setup he made for my 1360 motor. I like his solution for the oddball Vincent generator/alternator drive which on the stockers runs on top of the triplex primary chain, a narrow generator sprocket being driven by the centre set of links one tooth at a time. This was OK for the stock 60 watt generator, but hard on primary chains once 200 watt modern alternators were fitted to the same drive.
With the New by setup there is at least ten times the contact area driving the Gen pulley as with the original sprocket.



Here is what it looks like under the pressure plate. Note that there is no heavy centre hub. The steel plates are driven by hard steel dowels which are a sliding precision fit into the pressure plate at the outboard end. The contact area for the driven steel plates is huge and the round shape would likely never show wear or notching.

So in one step he designed away the big lump of steel in the centre while making the clutch stronger and eliminating the wear problems that always eventually occur with notching of the centre hub teeth.

I run a Steve Maney 40mm in my race bike, haven't touched it since the day I installed it and initial adjustment was set .
No issues and no signs of wear after 18 races and two track days.
Am putting a Steve Maney 30 mm on my 850 Roadster in the next few months.
Regards Mike

Brooking 850 said:

I run a Steve Maney 40mm in my race bike, haven't touched it since the day I installed it and initial adjustment was set .
No issues and no signs of wear after 18 races and two track days.
Am putting a Steve Maney 30 mm on my 850 Roadster in the next few months.
Regards Mike

Click to expand...

+1 :!: