Belt drive questions

[Hubie]

Hi All,

I may be in a position very soon to do a bit of upgrading to my BSA.  I will be fitting a belt drive to the dynamo for one, but I am strongly considering fitting a belt drive system to the clutch/primary.  I do have a few questions before taking the plunge though;

There is a mob called QPD in the states that makes belt drive clutches for these using a diaphragm type pressure plate.  I have heard that these are great things.  There is also a fellow not far from me who runs a business called Lytedrive and he also makes a belt drive kit with a six spring setup.  Both these systems have sealed bearings so that you can run the primary dry which is my main aim.

Does anyone have an opinion on what is the best belt setup, and since my rebuild I still have a few vibes up the rev range a bit (annoyingly at about 60mph) even after the rebuild and balance.  I am guessing that if a clutch/primary setup isn't spot on, it will contribute to the vibes so a better setup will reduce them.  Am I right or wrong?

Cheers,
Dave.

[mike667]

dave
 the QPD belt drives are really nice kits. Friend has one in his triumph. It took a bit of fiddlin to get it in but once in it works well, with the shifting being a bit easier than the stock set up. He hasn't really noticed any difference in "vibrations" so to speak. He changed it out as he was sick of the constant puddle under the bike from the primary not sealing properly. I have a belt drive in my norton (not a PQD) and it  makes the bike a bit easier to shift to - but other than that is not to terribly noticeable vibe wise compared to stock setup. Unsure about the lytedrive but i have heard they too are top notch. there is a guy in the UK that supposedly has a great system too that races triumphs etc available but his name escapes me now

I think the typical wisdom of using one of these belt drives in a bike like a BSA or a triumph (AKA a low powered motor) is they are a bit of a  bling factor - but if the major components of your primary are worn then it is a good thing to replace it with the belt drive system, but if you just need a new chain or a sprocket stick with the stock setup -  since  they last a long time and are considerably cheaper as a belt drive will run you  upwards of 1K, which means a lot of stock replacement parts

m

[phread]

I've heard nothing but good things about the QPD kits.  I am planning on putting one in my '52 A10 and my '68 A65T.

Some people have expressed concern about heat with the belt being enclosed in the primary, but I suspect that would
only be an issue if you were doing racing or long-distance touring.  I just cruise on my bikes and usually don't ride more
than an hour or two on them without stopping for a malted beverage at the local pub, so not really a concern for me.

Cheers,

Phread

[mark]

Dave,  I have fitted a Bob Newby belt drive clutch to my Road Rocket and am very happy with it. Cannot comment on whether it has any effect on vibration but it is a beautiful piece of engineering. Fitted straight on. Also no VAT or GST for us Aussies, It was about $800 delivered.

Mark

[Hubie]

I've ordered the Newby clutch.  They were very helpful and i waited a week and a half before hearing back from QPD.  Should arrive within a week so I can fit it before I go back to work.

Cheers,
Dave.