Cush Drive

tonythecat

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A friend of mine who is a VOC member but does not have internet access has asked me if anyone has any info on a cush-drive system. He thinks it was described in MPH in the 60's by a guy called Gordon Griffiths? any help would be appreciated.

Tony
 

ogrilp400

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G'day Tony,
What sort of info is he after?
Most motorcycles (and cars) have a cush drive some where in their drive train. Harley Davidson Sportsters' being the exception. Either on the crankshaft, in the clutch or in the rear wheel. Honda Gold Wings had one in the shaft drive. It is there to damp out power pulses and make for a smoother transmission of the engines power.

Phelps.
 

Hugo Myatt

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Rear wheel cush drive.

Gordon Griffiths was a clever bloke. As I recall his rear wheel cush drive did away with the sprocket side brake . The sprocket was mounted on a cast alloy outer plate with protruding vanes and in place of the brake drum was a drum with internal vanes with wedge shaped rubbers between, similar to the Royal Enfield practice. It was a very neat set up. There is an article way back in MPH. The bike was a Touring Rapide with many clever details.
 

tonythecat

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Thanks for that guys, it is obviously the one Hugo is talking about, does anyone know which MPH it appeared in?

Tony
 

Comet Rider

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Tony,
The newer version of this is called the "Torsion " sproket used by a lot of drag racers to take the shock off the drive train. It's available from the US in a variety of chain sizes, and they will machine the entre to suit your bolt pattern.

Neil
 

Tom Gaynor

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That's a neat idea. There must be a good few cushdrives that would do. I remember seeing one in a clutch that would fit easily, but can't remember where. Suspect it was Triumph.
Cheaper and easier however to change out the Series C ESA for the Series D, as advised by KTB. I did - it is a far more robust device - and also took the advice of Simon Linford, to use the gearbox to avoid beating the ESA to death. It isn't proof against wilful abuse. That said, mine runs very smoothly even at 30 mph in top, and the Renolds chain is 13,000 miles old, and has been adjusted once. And no, it doesn't drag on the ground...
(Another bit of advice, this time from Trevor, was to avoid mainshaft seals. There's little enough thrust area for the ESA as it is, and reducing it further isn't smart. My Series C ESA, even without seals, was slowly eating the main bearing spool, and the chain was already 1/32" out of line.)

For sale: mainshaft seal kit, bought and never used...

Tom
 
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Vincent Brake

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VOC Member
all

Hi Folks,
I machined 1,5 mm from the inner main bearing and made a new bush with a wider flange to carry the load.

Vincent

PS and by the way, I'll look into a rear left sided 2LS brake to fit, and will put such a damper on the right side
 

Diogenes

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QUOTE
A friend of mine who is a VOC member but does not have internet access has asked me if anyone has any info on a cush-drive system. He thinks it was described in MPH in the 60's by a guy called Gordon Griffiths? any help would be appreciated.
Tony
END QUOTE

Here is a late reply.

From '40 Years On' pages 215-216, see MPH 348 Gordon Griffiths and MPH 349 A.Lloyd.

I only have experience of riding the Gordon Griffiths bike and it was very much smoother than standard.
It also stood up well to being thrashed all over the Continent, two up.for years.

From Whitakerpedia 2.2-197-16 you can see a brief article and good photo by Gordon Griffiths, MPH 197.
 

davidd

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VOC Member
Tony,
The newer version of this is called the "Torsion " sproket used by a lot of drag racers to take the shock off the drive train. It's available from the US in a variety of chain sizes, and they will machine the entre to suit your bolt pattern.

Neil

I do not believe that Sertco is making the "Torsion Sprocket" any longer. It is an Ebay item now. They were a machining facility that got into the oil and gas boom. Rad makes a cush drive, but they are about $600. They can be used on the big KTMs, so they are quite strong.

http://www.radmfg.com/Cush-Series-REAR-HUB-125-up-p/radh-eq-1r.htm

David
 
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