• Welcome to the forum website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Online Forum Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this forum website.

    If you have previously registered to use this forum website, you should log in now. CLICK HERE.

    If you have never registered to use this forum website before, please CLICK HERE.

Cush Drive

tonythecat

Well Known and Active Forum Website User
Non-VOC Member
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

Well Known and Active Forum Website User
VOC Member
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

Well Known and Active Forum Website User
VOC Member
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

Well Known and Active Forum Website User
Non-VOC Member
Thanks for that guys, it is obviously the one Hugo is talking about, does anyone know which MPH it appeared in?

Tony
 

Comet Rider

Well Known and Active Forum Website User
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
 

Tom Gaynor

Well Known and Active Forum Website User
VOC Member
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
 
Last edited by a moderator:

Vincent Brake

Well Known and Active Forum Website User
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

Well Known and Active Forum Website User
Non-VOC Member
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

Well Known and Active Forum Website User
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
 
Warning! This thread is more than 9yrs ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Photos from the 2022 North American Rally

Photos from the 2022 Far Far North Rally

Photos from the 2022 Annual Rally

Photos from the 2022 French Rally


Top