belt primary

[tonydevon]

I was chatting with some local scooter guys, and I mentioned that all my brit engines I have built over the years, I fitted a belt drive primary, then said I would like to try and do something like that with a Lambretta

was then told that they already exist and in use, sure enough I looked online and found them.

I thought they were reasonably priced, should be quieter and smoother in use, generally I thought it was a good idea

BUT I never really see mention of them, hardly ever see them mentioned in specs of peoples builds etc

why is that??

[RICSPEED]

i can only think of maybe two that use one but have said the scoot seems smoother

[servetakid]

A chain works quite well as it is. Why change it?

[rosscla]

I think the main advantages are in the ability to change the ratios without having to change a chain and the weight saving. In theory the service interval should be longer and a broken belt will likely do less damage than a broken chain.

I was going to do this for mine but in the end spent the cash elsewhere, but on my wish list.

http://www.lambretta.it/Scheda%20Beltdrive%202010.pdf

[shocky]

A chain works quite well as it is. Why change it?

does a standard 200 cylinder pipe and carb work quite well ? if so why did you change yours

[tonydevon]

ok thanks guys, and thanks for that link, hadnt seen that

Im probably going to be starting from empty cases off ebay etc when I get round to building my engine, so I suppose that Im not looking at the full expense, as I will only be buying the parts I need, not buying an engine with chain drive and then binning that.

Im still surprised at how uncommon it appears, I know the old story of "if it aint broke dont fix it," but then we would all be on 6v and points.

more investigation needed before its added to my shopping list, but I do like the idea. although I have read a report that reckons the belt ruined low down smoothness?? reckoned that it needed to be revving about 2500rpm rather than 2000rpm with the chain to get it pulling smooth, I thoguht the belt would give a cush drive effect and make it better.

[servetakid]

A chain works quite well as it is. Why change it?

does a standard 200 cylinder pipe and carb work quite well ? if so why did you change yours

To add to the overall usability of the bike on a long distance run. I understand that the belt does offer some advantage, it doesnt howver make as much difference to the over all ride in the way that a pipe, carb or cylinder does. Most people already have good working chains, sprocket and clutch sprocket which have already been tailored to their set up... SO why buy it all again? I would however consider it as an option if i were to stant another engine rebuild, but i am in no hurry to change all my good engine inards.

[CANbus]

A chain works quite well as it is. Why change it?

Ok you have asked twice here are some of my thoughts, right or wrong.
Already mentioned smoother running, less frequency through the engine components.
Less damage in the gearbox should it fail,
No chain guides, I have never had a problem I know others have?
Possibly could be set to slip on a piston lock up, safer ?
Possibly runs on less or no gearbox oil ( I have a leaky breather, I'm sure it's pumped out more oil than I have put in )

[a.lo.v2]

i thought a magazine review of the time said the gear changing was a bit more jerky due to no cush drive. do belts not need the cush drive? i have never seen/heard any feedback on this product or know of any one using it. was this another innovation for the targa twin?

[RManson]

Seems like a good idea to me and one that has been picked up in other applications. The pros have been outlined fairly well in the prior posts. This is fairly common with Harley setups among others (belt drive between engine and gearbox) which is essentially what is being done here, sans cush drive. I guess you have to ask yourself how many engines have gone 'bang' due to chain or related failures and then determine whether such an upgrade is worthwhile.

-Ryan