Maney Belt Drive

Ms Peel's 40 mm Maney primary IIRC is 36/72 - 2:1. Not tired yet of course.

I go 35-45 on my way to hyw stability so a few miles in 4th barely at healthy oil pressure. After my gearbox lesions - pangs of pain prevent me from staying in lower gears long or on much load. Factory got it pretty right for sane board useage. But if bike never saw 80 mph might try a 17 tooth so at least pull you mouth back and front up getting to 45. That way you could use up tires like the rest of us and no worry about oil wedge endurance.

Holmeslice said:

DogT said:

But I'm not racing, I'm cruising around these country roads where the speed limit is 45 and sometimes I get up to 60.

Dave
69S

Click to expand...

Dave, let's say currently you have a stock primary setup with a 26/57 primary sprocket tooth count (2.19 primary ratio), plus a 20 tooth countershaft and a 42 tooth rear wheel sprocket (2.1 final). That puts your overall gearing at 4.60:1 If you want to keep that same overall ratio with a Maney kit, you'd have a 38/70 tooth primary (1.842), which would require a 17 tooth countershaft sprocket with your 42 tooth rear (2.47 final) to get you close and put you at 4.55 overall ratio.

That's 3 teeth on the countershaft sprocket. I was surprised by this myself and double checked my math. But yes, 3 teeth smaller to get your overall gearing close to the same as stock.

Click to expand...

i'm pretty sure that 3 teeth are all that Dave has left - (which is two more than most around here!)
so he'll have to think of some other options :shock:

Holmeslice said:

Maney's belt drive primary ratio is 1.84:1, whereas stock Commando is 2.19:1. This taller ratio speeds up the gearbox and thus reduces torque shock loads, something the JPN team implemented that helped them finish races.

Click to expand...

True Kenny, but following the direction of JPN in '75 I used 33/57 on triplex chain, giving 1.72, and I certainly did use a 17 gearbox sprocket, with 40 to 46 rear wheel sprockets with 19" rims. Certainly worked I did not take the gearbox cover off in 4 seasons.

Norman White indicated recently about 1.78 when I discussed primary ratios with him, and with stronger modern gearboxes (TTi) you don't need to be so extreme, I am guessing Steve has it about right to find both a race and road set up.

Steve

Actually, I've got a 19 tooth counter tooth sprocket, which puts my total gear ratio at 4.84. That's kind of what I'm talking about, I don't need the taller ratio at all. On these back roads, I don't need the tall ratio, 50mph in 3rd gear is getting close to lugging. Since I don't have 3 teeth left, I'm not sure the Maney drive could get me there or can the primary ratios be adjusted to what I want?

Has anyone anything good or not to say about the Norvil belt kit which he will supply in nearly any ratio you want? Not that I wouldn't try to figure the Maney kit if I could make it work in my ratio. It sure looks good and has good reputation.

Just looking for information.

Dave
69S

I have used a few norvil kits with no issues. Like ALL belt drives it is all in the setup. stock ratio is 2.19 and the standard norvil is 2.187 so close enough.

DogT said:

Actually, I've got a 19 tooth counter tooth sprocket, which puts my total gear ratio at 4.84. That's kind of what I'm talking about, I don't need the taller ratio at all. On these back roads, I don't need the tall ratio, 50mph in 3rd gear is getting close to lugging. Since I don't have 3 teeth left, I'm not sure the Maney drive could get me there or can the primary ratios be adjusted to what I want?

Has anyone anything good or not to say about the Norvil belt kit which he will supply in nearly any ratio you want? Not that I wouldn't try to figure the Maney kit if I could make it work in my ratio. It sure looks good and has good reputation.

Just looking for information.

Dave
69S

Click to expand...

Dave, it sounds like for the work you do you should be going down to at least an 18 tooth gearbox sprocket, even with your current primary ratio! Have you tried that? the sprocket from any AMC application will fit if it is not in the lists of Commando suppliers. Certainly the sprocket specialists should be able to help....and if you fit another primary set up the 17 might be needed if you end up with a ratio lower than 2:1

Do remember that I don't think changing the sprocket is a lot of work, but with the primary cases and alternator etc. you may think it is.

Or do you need to keep a higher ratio for occasional highway work? if so, live in 3rd

As for changing the ratio of a belt drive, drum size is fairly limited due to clutch plate size.....68, 70 and 72 seems to be it for Commandos. So its change the pulley...I think Maney only does one, but ask him. For your needs, which seems to be changing the front pulley for a smaller one, typical limitations are that for a road bike go to small and you will have clearance problems with the alternator rotor, for others, go too large and you will have clearance problems with the alternator support posts.....not a problem for a lot of racers, Norvils range are unlikely to have clearance problems in teh correct application!

Different suppliers use different belts and tooth profiles, but front pulleys can be had from around 30 teeth to 40 teeth, most seem to be 32 to 38. Different suppliers have different solutions for the keeper plate, some seem better than others, but very few seem to shed or shred belts....

I have a picture of a very shredded belt on an RGM setup, but very hard use and other set up problems were at the root of that....

There was recently a lengthy discussion on belt drives. I believe there are comments on the Norvil kit here:

primary-belt-drive-pros-and-cons-t11169.html?hilit=belt drive pros

Dave, I might wonder whether you should change to a belt drive at all. I certainly understand the pleasure of unhurried cruising on country lanes at lower speeds and light traffic. If the bike works well for what you enjoy, then maybe you should just enjoy it! Just a thought.

Russ

DogT, I'd sure go with a 17 for 4th gear doddlling as AMC trannies eat their sleeve bushes in every gear but top. DAMHIK : (
I'm a bit confused and torn between compromise of lugging engine in 4th vs chewing bushes in 3rd. So your dilemma is continue as you are and have to take gear box apart soon or lessen wear/effort taking of primary to put on 17T. Only real trauma in 1' removal is the dang crank sprocket, which needs a good heating before expecting puller applied to pop in off in hand with one good rap on the puller shaft. I've popped 2 pullers so far one a cheap steering wheel type the other purpose made robust factory kind ugh. The safety in slow travel on loose stuff is instant ability to spin/chirp/skip rear .5 sec worth to swing rear of bike a bit so thrust then aims away form hazards. Slowing is only ever done with bike total upright tires totally in line.
Never ever enter a corner so fast you can't be on some throttle if ya like, even if merely light feathering throttle, brakes are TABOO with fork turned or bike lean ANY at All. Or if can find low ratio belt system then win win but for the tedium of down time to install, which by now may mean opening gearbox to replace sleeve bush so belt stays on not collect all bunched up chewed up around crank pulley. ugh.

I'll most likely stick with the chain drive for now. It's not like I'm in a big rush to go belt, it's not giving me any problems and I don't even have the seal to the gearbox, but I'm using dino oil in the GB. It's good to know the Norvil setup is good though. Give me an option. Thanks.

Dave
69S

What clutch plates are used in the Maney system?

Same type as non Maney clutch baskets. More plates the better of course.

Just talked to Steve and ordered one. It uses all the stock clutch internals. Questioning him about venting the primary for cooling, he said there is a lot of hype about that and not to worry about it. Heat shouldn't be an issue.

mikegray660 said:

Steve's standard street belt drive ratio it makes it seem like you have approx a "1 tooth" larger gearbox sprocket than what you actually have on the bike (so if you have a 19 makes it seem like a 20)

I have a 21 tooth on my bike - and its great for high freeway speeds etc etc - 70mph is under 4K

i found it to be a little over geared when i lived back east as spent a lot of time on smaller roads - sub 55-60 mph - so was almost always in 3rd

the change does make it a bit tougher to kick start it too - so if you struggle with your bike currently it will seem a little harder to kick over

fortunately i am 170 lbs of pure adrenaline fueled nitro-muscle (haha)

Click to expand...

Hi Mike
As I have just bought a Norvil belt drive kit as a part of a thorough rebuild of my bike, I thought it would be interesting to follow this topic. My bike also has a 21 tooth g'box sprocket.

The kit I bought has a ratio of 2.12 : 1 compared to 2.19 : 1 for the chain drive, which will speed the gearbox up a bit. When it comes to kickstarting, I would have thought this would result in a "gearing down" effect gearbox - to - engine, and so make starting a bit easier. With a 1.84 : 1 ratio, the Maney kit should make it markedly lighter to kick.

Or is it that the slower turnover makes the engine less eager to start?

Or have I got this thought process totally and utterly wrong?

I caution the wisdom to ride long in lower gears, even though I must do that a good bit, I know for sure its a faster way to wear away the sleeve shaft bushes that can not get lube while turning at road speed, then clutch begins to wobble and belts tend to pack up completely behind Alternator and pulley. Kick wise the higher the drive train geared to turn tire faster the easier for kicker or tire to spin engine. I don't think oil wedge protection is effective in Norton until engine is over 2500 rpm, so more cam wear on 'lugging' about - while may be easy on drive train -still puts same spring loads on cam lobes/lifters. Change tranny sprocket to suit ones cruise conditions to stay in 4th over 2000 rpm. Feel guilty of abuse of tranny bushes, 1st gear especially when not in one-one 4th. A good Cdo should enjoy over 4-5000 rpm all day long with minimal wear tear.

Snakepit said:

Just talked to Steve and ordered one. It uses all the stock clutch internals. Questioning him about venting the primary for cooling, he said there is a lot of hype about that and not to worry about it. Heat shouldn't be an issue.

Click to expand...

Did you happen to talk about the need for his outrigger on a street bike? I would be curious as to what his thoughts are on this. I would also like a report here once you get the belt drive installed.

Thanks
Russ

I have one of his outriggers on my Alloy bike along with a fair spares belt drive. Just from a static installation, everyone should use one. The clutch basket, even the belt drive ones are hanging way out there on a fairly small shaft, and it's quite a bit of weight moving up and down in and out and torqueing on and off, It is a lot of stresses. I am suprised the shaft does not break more often, but I do know they are often bent. Then there is the bushing wear to contend with.

It looks like the MK3 inner primary chaincase has a half assed attempt at this. It's just an oilseal, but the case limits flexing somewhat. I wonder what the longevity of this seal is and if anyone has fitted a bearing in place of the seal.


Dam it, now I just came up with an idea. More aluminum and a few hours wasted. I'll report back if it works. It might be a bolt on easier than a maney outrigger idea.

A bit late to be chiming in, but here goes....

I fitted an RGM to mine, and had the same issues as Swoosh with the domed fasteners, but no 'biggie'. Sounds gross when trying the kickstarter though

I recently received 2 more from RGM and they've revised the design so the fasteners are now countersunk, and the basket has a flange on the outside to prevent the belt walking outboard.





I also have some Maney stuff, and it's too nice to pollute by actually using it


Just thought I'd redress the balance a little.

Well you are not the 1st with idea to use primary case as part of crank and clutch bearing support, so consider the crank end too while dreaming up double use of primary case mass. Maney out rigger requires a big hole in inner cover, so I'm thinking to weld out rigger into inner case hole to both seal the grimy-grity area and solid up the whole primary case that will also support the Drouin drive belt loads. I know for a fact that the shafts are hard to break but not too hard to twist up like a Barber shop spiral sign. I mostly straightened main shaft once but took a long time of smacking it while following the new offset until I realized it was like un-twisting a twist tie wrap and stopped at .015" or so run out.

Definitely no need to vent for heat on belt or the alternator and after having some grit get inside realize the weak link in belts is the rubbing on edges unraveling, so will vent Peel's for fun with forced ram air duct and vacuum venturi clutch spin air pumping exit, though a filter. My Grit conditions are not normal though. Peel's vents will not be very visible so not a decorative modification like the others venting art work.

rvich said:

Snakepit said:

Just talked to Steve and ordered one. It uses all the stock clutch internals. Questioning him about venting the primary for cooling, he said there is a lot of hype about that and not to worry about it. Heat shouldn't be an issue.

Click to expand...

Did you happen to talk about the need for his outrigger on a street bike? I would be curious as to what his thoughts are on this. I would also like a report here once you get the belt drive installed.

Thanks
Russ

Click to expand...

No outrigger fitted. I just ride on the street so probably not necessaryI did fabricate a double tension adjuster though. I sure like the system