Belt Drive with factory Electric Stater?

I would like to convert to a belt primary drive on my Mk3 but retain the electric starter (suitably upgraded). RGM offer such a belt drive kit - does anyone have any experience of it or another brand used in conjunction with the factory electric starter? I'd also like to fit a Maney outrigger bearing at the same time if it's possible with the belt/electric starter? Any comments from those with first hand experience would be greatly appreciated.

To retain the e-start means you will need to keep oil in the primary or the sprag clutch will fail. Kind of defeats the main benefit of running a belt in my opinion. Jim

why can't you run a belt in a primary with the Mark3 fluid level?

the oil would lubricate the belt like it does the chain

I understand some belts do specify they can be run wet

why would be the concerns, like can lube degrade the belt over time, or make it somehow slip on the teeth?

The main reasons for wanting to convert to a belt was to run the clutch dry and to allow the fitting of an outrigger bearing for the mainshaft. If I've still got to run oil in the primary chaincase for the sprag's continued good health I'll just stick to a chain.

Hi
As RGM do a belt drive for the estart mk3 I guess the belt must be ok in oil, or they think it is ok to run it dry! an email to Rodger at RGM will give up the answer.
JohnT

JohnTy said:

Hi
As RGM do a belt drive for the estart mk3 I guess the belt must be ok in oil, or they think it is ok to run it dry! an email to Rodger at RGM will give up the answer.
JohnT

Click to expand...

FYI The SYNCROFLEX belts can run wet or dry.

The main reason for going belt is the lack of knowledge regarding chains.

The vast majority of triplex chains available are of dubious quality, even those offered by "Norton Dealers".

A Renold costs around £60 yet Norton companies offer one at under £30.....think about it.

Even the Renold is not the chain it was 20 years ago. There is a bullet proof option in a duplex,
yes a duplex from iwis which has been used widely on Laverdas for many years. Better than a triplex
and better than a belt.

Andy

andychain said:

Even the Renold is not the chain it was 20 years ago. There is a bullet proof option in a duplex,
yes a duplex from iwis which has been used widely on Laverdas for many years. Better than a triplex
and better than a belt.

Andy

Click to expand...

Just curious, but what features of the chain convince you that it is superior to a belt? As far as I can see, the biggest advantage of the belt is light weight, ability to run a dry clutch (maybe not for a Mk 3), and the availability of a variety of primary drive ratios. You can run other primary drive ratios with chain, but doing so requires custom fabrication, not off-the-shelf availability. The advantage of the chain in an oil bath is longer life. Are there other considerations I'm missing?

Ken

The fact that the original Renold chain ran for many tens of thousands of miles is a clue.

I know of many belts loosing teeth and it is not a cheap fix. For a dry racing clutch then a belt
is fine. It does many fewer miles than a road bike and usually gets better services.

The duplex chain the Laverda guys are running are lighter than a triplex and there are Nortons now running
mostly in Belgium, where they take to change more readily.

Given that most owners want to keep the bike standard looking. It is a good option.

Regarding weight, most belts are considerably wider than the corresponding chain and this makes the
pulleys heavier.

At the end of the day it is personal choice as long as people know what is available.

Andy

belt life?

I replaced my primary belt after 28,000 miles of usage just out of general principle as it looked quite good.

I have never had any teeth sheered away and once set correctly have had no need to adjust the tension.

A belt is much lighter than a chain and also quieter, providing a no leak primary and clutch plates that stay dry and do not slip or need periodic cleaning.

I can see your point, Andy, and the only part I would disagree with is the bit about the belt pulleys being wider and therefore heavier. The chain sprockets are steel where the belt pulleys are aluminum, and the pulleys end up being lighter than the sprockets. FWIW I tried an aluminum clutch basket with the triplex once and it wore out almost immediately, so I don't think that's an alternative.

The factory team back in the John Player F750 days seems to have agreed with you. The factory bikes ran a duplex chain, not the standard triplex, They experimented with belt drives, but decided they weren't reliable enough at that time. Belt drive technology has improved a lot since then, and the reliability of the Commando kits now is quite good. As you say, it's up to personal choice.

In terms of reliability, I've personally had both triplex chains and belts fail on my Commando race bikes, but only once for each. When the chain failed it trashed both the inner and outer primary covers, and damaged the crankcase. When the belt failed there was no damage except needing a new belt.

Do you have any details on how the Laverda duplex chain is adapted to a Commando? Is it the same pitch as the triplex so you can use stock sprockets, or does it require a special engine sprocket and clutch basket? My memory says the factory used a larger pitch for the duplex, but I'm not positive.

Ken

The duplex chain used by Laverdas is a Mercedes diesel cam chain. The iwis part is D67HP.

It is a duplex 3/8 chain and will go straight on the triplex sprockets using just 2 rows of teeth.

There is a designe problem with all multistrand chain in as much as the pin has a small dia, 3.31.
The middle plate or plates are a slide fit allowing pin flex, especially on triplex.

The Merc chain has a bigger pin at 4.44 and the middle plate is a press fit so the pin is not only
shorter and fatter but supported. It is also a bush chain, no rollers to fail. Being duplex it is also lighter than a triplex.

It has been tested on a T160 and ha done over 40,000 without adjustment. Laverdas have been using it for years without
any problems and it has also stopped failures on a wonderful machine The Carberry Enfield.

The reason for all this is simple, the triplex chain is little used in industry now so most are built to a price
rather than a quality, there are some real shockers out there so beware. Renold triplex, not the same today as it was,
sells around the £50-£60 yet some dealers offer a triplex at £20-£30.....work it out.

Andy

As with many things chains have improved over time.

The trouble is most people dont know.

Merc chains for the diesel engine have a bush not a roller, so no bits of roller floating about.

Material has also improved greatly along with build qulaity and tolerances.

I am fortunate as I was MD of iwis UK for many, many years and had inside knowledge of what was available.
I now play as I am retired. It is interesting to note that on some race engines used on TVR and Jag there is
an iwis single chain that replces the duplex cam chains.

I have no problem with belts persay but feel that some change for the wrong reasons.

I raced karts, only 210, but some changed to belts and I remember getting sprayed with teeth. I ran a chain
and it lasted for 2 seasons, and yes I was quick.

I am not trying to sell chains, although I do but educating people so that they can make informed choices.
I stand by the fact that there is a lot of rubbish on the market so deal with companies that market good
products.

Just to show my motives a good supplier of chain is Sprockets Unlimited and I am nothing to do with, quite the
reverse actually.