Belt drive on A10

Jerry Doe · Oct 20, 2022

I want to put a belt drive in my A10 primary. The original setup has a Cush drive on the crank. I think that’s important to keep a Cush drive there. Belt drives seem to eliminate that Cush drive. Any feedback from anyone who has fitted a belt drive to an A10 after removing the Cush?

Probably a better question. What is the best belt drive kit for an A10?

Cheers
Jerry

baz · Oct 21, 2022

Jerry Doe said:
I want to put a belt drive in my A10 primary. The original setup has a Cush drive on the crank. I think that’s important to keep a Cush drive there. Belt drives seem to eliminate that Cush drive. Any feedback from anyone who has fitted a belt drive to an A10 after removing the Cush?

Probably a better question. What is the best belt drive kit for an A10?

Cheers
Jerry

Don't know about a belt drive kit
But why not use a triumph clutch?
I have one on my A10 albeit a rigid hub type
You could use the type with a cush drive hub
They are generally accepted as being a better clutch
If you are going belt drive you won't need the BSA/triumph adapter as you won't have oil in there so just a standard triumph centre would work

Onder · Oct 21, 2022

The only thing I can add is to make sure you can seal the gearbox shaft. On my Commando I have a TTI box so no issues there but on my Enfield I have a stock Albion box and it is less than oil tight. So off with the primary cover fairly regularly to do a bit
of a wipe down. Granted, I am some what anal so don't see this as a show stopper.

baz · Oct 21, 2022

Jerry Doe said:
I want to put a belt drive in my A10 primary. The original setup has a Cush drive on the crank. I think that’s important to keep a Cush drive there. Belt drives seem to eliminate that Cush drive. Any feedback from anyone who has fitted a belt drive to an A10 after removing the Cush?

Probably a better question. What is the best belt drive kit for an A10?

Cheers
Jerry

I have to ask
Why do you want a belt drive?
Also if you do go for a belt make sure you order the ratio you order is about right

Fast Eddie · Oct 21, 2022

If you use a rubber belt, the teeth do ‘give’ somewhat and allegedly provide some cush effect. I have run rubber belted Bob Newby belt kits on Triumphs, that do away with the cush drive, with no ill effect.

I believe riding style is also at least / more important. I think the Brits had such ‘good’ cush drives cos folk were obsessed with ‘min mph in top gear’ and probably lugged their motors back then, they also often bolted large heavy sidecars to ‘em.

If you avoid lugging the motor, you‘ll do your drive train the world of good.

I’d contact Bob, he shows a nice Goldie belt drive on his web site, worth asking if he does an A10. His kits are not the cheapest, but yiu get a lot with them (ie complete clutch) and the engineering is top notch.

http://www.bobnewbyracing.co.uk/bikes/BSAGoldStar.jpg

baz · Oct 21, 2022

Fast Eddie said:
If you use a rubber belt, the teeth do ‘give’ somewhat and allegedly provide some cush effect. I have run rubber belted Bob Newby belt kits on Triumphs, that do away with the cush drive, with no ill effect.

I believe riding style is also at least / more important. I think the Brits had such ‘good’ cush drives cos folk were obsessed with ‘min mph in top gear’ and probably lugged their motors back then, they also often bolted large heavy sidecars to ‘em.

If you avoid lugging the motor, you‘ll do your drive train the world of good.

I’d contact Bob, he shows a nice Goldie belt drive on his web site, worth asking if he does an A10. His kits are not the cheapest, but yiu get a lot with them (ie complete clutch) and the engineering is top notch.

http://www.bobnewbyracing.co.uk/bikes/BSAGoldStar.jpg

Commoz maintains that there is more cush in a chain than a belt because each link pin is or should be cushioned by oil
I once had a cb750 with a set of 3 spokes
No cush drive
It was like getting kicked up the arse when you put it in first
And keeping the sprocket bolts tight was a nightmare

Fast Eddie · Oct 21, 2022

baz said:
Commoz maintains that there is more cush in a chain than a belt because each link pin is or should be cushioned by oil
I once had a cb750 with a set of 3 spokes
No cush drive
It was like getting kicked up the arse when you put it in first
And keeping the sprocket bolts tight was a nightmare

That’s a good theory. But very difficult to prove either way.

As you cannot compress oil, the only cush effect I can think of is the damping effect of the oil being squished out of the rollers.

If this is so, then it’s a kind of ‘one shot’ effect as once the oil is squished out, it’s out until you back off again, and the oil has time to ‘fill’. Whereas rubber teeth, or cush drive, remain able to absorb some shock from every firing pulse.

Its all theory and semantics of course. But I doubt Jerry is looking at a belt to ’increase’ the cush drive effect. He wants the other benefits of a belt (light weight, dry running, low maintenance) and just wants to know if it has ‘enough’ cush effect to prevent causing other problems.

baz · Oct 21, 2022

Fast Eddie said:
That’s a good theory. But very difficult to prove either way.

As you cannot compress oil, the only cush effect I can think of is the damping effect of the oil being squished out of the rollers.

If this is so, then it’s a kind of ‘one shot’ effect as once the oil is squished out, it’s out until you back off again, and the oil has time to ‘fill’. Whereas rubber teeth, or cush drive, remain able to absorb some shock from every firing pulse.

Its all theory and semantics of course. But I doubt Jerry is looking at a belt to ’increase’ the cush drive effect. He wants the other benefits of a belt (light weight, dry running, low maintenance) and just wants to know if it has ‘enough’ cush effect to prevent causing other problems.

On my commando I have a belt drive mainly to reduce the weight hanging off the end of the main shaft
I have an apprilia back wheel with a large cush drive
Iwis chain
Barnet plates
And this setup is superb, probably the best clutch/gear change I've had on any bike I have owned

Jerry Doe · Oct 21, 2022

Thanks for these good answers.

The main reason for a belt drive is to run it dry. Less weight. I do have a standard 4 spring clutch, which is supposed to be better than a 6 spring. I need to see if it’s useable. I have the SRM gearbox main shaft seal already fitted.

I think since this bike is costing so much, that I might keep it standard and try to make it oil tight. See how that goes. It’s pretty easy to add a belt later if need be. Stay tuned. Should be getting motor back in very soon,

baz · Oct 21, 2022

Jerry Doe said:
Thanks for these good answers.

The main reason for a belt drive is to run it dry. Less weight. I do have a standard 4 spring clutch, which is supposed to be better than a 6 spring. I need to see if it’s useable. I have the SRM gearbox main shaft seal already fitted.

I think since this bike is costing so much, that I might keep it standard and try to make it oil tight. See how that goes. It’s pretty easy to add a belt later if need be. Stay tuned. Should be getting motor back in very soon,

Don't make the mistake I made by putting too much oil in the chaincase
I re made the sliding plate behind the clutch
And fitted a proper oil seal etc
But the reason mine leaked was because I filled the case until the chain was in the oil
Instead of being just below the chain

Matchless · Oct 21, 2022

I think SRM sell a cush type engine pulley for belt drives. Not sure which type of belt though.

Martyn.

Belt drive on A10

Similar threads