Cush Drive/ to cush or not to cush?

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geo46er

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Greetings, Now that winter has set in I have been considering an alternative wheel project for my Commando. I have recently seen photos of "other" wheels installed on a Commando sans cushdrive. I know its there for a purpose and that the majority of modern bikes use them, and yet there are a number of bikes that do not "mostly racing dirt bikes". I was hoping for someone could share opinion/observation/experiences regarding this matter.
 
As hard as Commandos are on their transmission gears, I wouldn't be looking to take out the cush drive. Making it a better cush drive than stock is the way to go. I am told that Ducati's had a well made one for some years.
 
The first couple of years of Commando production used the bolt-together rear hub with no cush drive. If you are worried about giving the transmission an easier life a belt drive acts as quite an effective way of reducing drive shock.
 
dave M said:
The first couple of years of Commando production used the bolt-together rear hub with no cush drive. If you are worried about giving the transmission an easier life a belt drive acts as quite an effective way of reducing drive shock.
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Not according to many who seem quite knowledgeable about belt drives. Why do you say the opposite, Dave? I run a belt drive on my Commando, but I have no idea whether it reduces shock to the tranny or not.
 
Belt cush effect

Greetings again, I do run a primary belt, and prior to its installation I do remember reading in a thread (NOC site I believe) a posting claiming that belts offer no cush effect, evidently Jim C has read the same posting.
I never run my bike hard, IE. no dragstrip launches, clutchless shifts, etc.. I wonder from an engineering standpoint if that sort of use is what the cush drive protects against, or is endless hours droning on the interstate just as wearing on the gears due to countless power pulses. Although, correct me if I am wrong, I think once in 4th gear there are no gears involved in the power flow.
 
Jim, I run a belt drive on my 750 cafe racer and a standard triplex chain on my 750 roadster. It may be just subjective, but I feel that the cafe racer is a little less harsh in the drive train. I do have a cush drive on both of these bikes though. I have also talked to others who concur, the fact that the belt system is lighter than standard may be a factor. You do have to run the belt slacker than you might imagine as it seems to tighten up considerably when warm and is then less easy to shift and not as smooth. I am nearly finished with the restoration of an S-type, which has the original bolt-up hub, so I will be interested to see what difference, if any, there is between them. I am willing to concede that my cafe racer may just have a sweeter drive train than the Roadster - watch this space for when I get the S-type up and running
 
H-D has run belts on primary and final drive for years, primarily to improve ride quality and reduce maintenance. Even so, they've added cush drive recently (which they call IDS)

Modern bikes have pretty good cush drives, and the cush on the Commando looks really primitive in comparison, but I guess it works.

Here's a pic of the cush drive on my Speed Triple:
Cush Drive/ to cush or not to cush?


This of course would not work on the Commando, as it is a SSSA

One cush rubber contains more rubber than the whole Norton cush assembly.
 
Cush -ESA

a cush drive or ESA (engine shock absorber) protects your driveline from the constant pulses put out by an engine. by removing the ESA in any assembly you allow the pulses to be absorbed in all the non 'free-wheeling' assemblies such as splines and keyed shafts for instance. whether it's street or track an engine loads and unloads the driveline constantly.
hope that helps.
marc
 
There was once a fellow on this forum and others that probably knows more about the Norton clutch and its weakness than most of us put together. His racing days showed that it was the weight of the clutch basket and the chain and all of its components that were so hard on the transmission. There is no doubt a cush drive will help, But reducing weight would be my concern also. One way to do this is with a belt drive as it has a lighter basket and the belt weighs less too. Boy this may start another one of those GREAT threads. And we also know that the trans is a bit undersized for the job, So do what you can to help it, ie no dumpin the clutch, Tall wheel stands and the like. LOL He once called the clutch a flywheel, You guys know whom I speak of, And if your out there BDM Have a great day, Chuck. :lol: :lol: :lol:
 
Yes Chuck........if BDM is somewhere , I am with you to wish him a merry X-Mas........and to get more info about belt , just jump on the other forum and make a search. I had learnt more in few months in reading those posts than in many years.To resume , he said that a belt had "normally" no cush effect (just but just is very important a huge massive gain in saving rotating weight) , he said that the Norton cush system was awfull (did you looked at those plastic tablets as hard as ...).
But sorry I had no other way of smoothing the drive train, RGM propose any "italian" rear sprocket with built in rubbers, no background.The frozy frog.......Pierre
 
Hortons Norton said:
There was once a fellow on this forum and others that probably knows more about the Norton clutch and its weakness than most of us put together.
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If you were indeed referring to "beltdriveman", then I don't think he's ever been a member of this forum, - as far as I know?
 
I must have the two mixed up L.A.B. Sorry. For some reason I thought he used to post here too. My bad. :oops: :oops:
 
belt as ESA or 'cush'

in order for an ESA or cush to be effective, there needs to be a means of 'absorption' of the pulses created by the engine. a belt is as ineffective as a chain for absorption - the reason for this is a belt is not intended to stretch at all, these typically have a wire mesh at their inner core making them able to withstand the rigours of serious stall torques.
cheers,
marc
 
Hortons Norton said:
I must have the two mixed up L.A.B. Sorry. For some reason I thought he used to post here too.
Click to expand...

No problem, as I can't ever remember him posting in the time I've been here, and certainly, once read - he's never forgotten, but I don't think there were two of them? :shock: As beltdriveman was often referred to as "BDM" over on the Britbike website.
"dynodave" used to be a regular forum contributor some while ago, and he also has a very good working knowledge of the Commando clutch, so maybe it was dynodave that you were thinking of who used to post here?
 
It seems to me some of the early Norton's or BSA's had cush drives incorporated in the clutches. This would seem more effective in reducing pulse strains on the transmissions than the cushed rear hub. Maybe both are the answer. Heck, who's going to be 1st. to make an automatic transmission! (or has this been done already)
 
Honda had one called the Hondamatic, In fact I think they had it on a few bikes. Talk about spoiling the fun. :roll: :roll:
 
Not only Honda, Moto Guzzi had the Convert 1000. Fortunately the trend seems to have died off.

Peter Williams, the great Commando engineer for NVT and racer for JPN remarked that the biggest limitation on the Isle of Man 750 racers was the weight of the primary transmission, mostly the clutch assembly. His view was that if belt drives where available in the early '70's they may have had even more success.
 
No cush MKIII

I have been runnning without a cush on my MK III for several years . It is harder on the trany parts, but not extreme.
 
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