New Cush Drive

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madass140

madass140

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thought I'd start another thread leading on from the sprocket/drum which was about sprocket/drum material.
Here is my proposed production cush drive, it will entail casting new hub and casting new steel sprocket/drum,
sprocket is fixed at 42t , I dont think there is much call for going bigger than 42t for normal road use.
assembly will allow use of standard brake and hub cover and of course my ever popular one piece axle.
New Cush Drive

New Cush Drive

New Cush Drive
 
What was wrong with the stock one?

I'd say that if you could design a hub that could take a replaceable sprocket it would be gold.
 
Well I have a small mountain of standard ones, ALL with loose pegs, maybe I was the only one that ever encountered a problem with the stock cush drive.
my item is not about sprockets, its about an improvement to the cush drive for those that may be interested in a better setup.
standard sprocket/drum from Andover is only about $100, how often would you be replacing one?
 
swooshdave said:
What was wrong with the stock one?

I'd say that if you could design a hub that could take a replaceable sprocket it would be gold.
Click to expand...

I've always thought the stock pre-MkIII cush setup is kinda useless. The idea is to protect all the components in the driveline from shock loads, especially the transmission. The spalling on the faces of gears is from hammering that's pretty easy to minimize with a functioning cush system. Besides, then you can do clutchless upshifts with an easy conscience.

Don, if you decide to make these are you going to do some kind of case hardening for the sake of the sprocket? I had a sprocket go from normal looking teeth to bumps in one afternoon on the road back home from Alaska in the Yukon. The dust up there is like some kind of pumice valve lapping compound. The guy that turned down the sprocket and welded on a replacement said that it was cast steel with some kind of surface hardening. Once you have worn through it, it is pretty soft stuff.
 
Bob, actually the standard genuine cast steel sprocket/drums wear fairly well, but yes thats a quest to determine suitable material for brake drum and sprocket, no doubt good foundries could guide me on this also.
the sprocket has to be soft enough to machine but hard enough to cope, so yes maybe hardening of the sprocket post machining would be the go.
 
On 5/4/2013 10:46 PM, Toll Fast wrote:
> Depends upon which bike you are talking about.
> BSA used Nikasil which is a nickel silicon iron.
> Casts beautifully work hardens.
> Usually they were cast and then the hub was attached by either rivets bolts or being cast into the alloy drums.
>
> Bike Beesa
> Trevor
 
I would have thought that a brake drum with a bolt on sprocket would be the go. Then it would allow easy change of gearing . Your hub looks very much like the items used on 70s Suzuki two strokes . If I was going to do that stuff, I'd go to the wreckers and look for something to modify. The number of spoke holes might present a problem though.
 
again, to run a standard 42t sprocket (standard) its not really successfully possible ,at least for a massed produced item to have a bolt on sprocket on the 7" drum. I would say probably 95% of Nortons on the road are using standard 42t sprocket, I really dont think most owners wouls be continually changing their gearing, they normally make a decision what gearing they want and change the gearbox sprocket at tear down or rebuild time and I would say most times they would opt for a bigger gearbox sprocket, now if thats the case and they wish to gear up then fitting a 40t rear sprocket is not successfully possible unless I cast sprocketand machine sprocket drums with different teeth count,
my main object is to have a decent trouble free effective cush drive with one piece axle,
 
Your hub looks very much like the items used on 70s Suzuki two strokes .
Click to expand...

Hehe, no way are they are good looking as maddass's stuff but that's what Peel's uses to avoid what maddass went through. There were about 2-3 yrs of spoked rim hubs for rear disc brake, mostly on big triple 2 tokes then cast wheels became the standard issue.
 
my main object is to have a decent trouble free effective cush drive with one piece axle,


And still be pretty easy to change out the wheel and reassemble ....
Looks like a winner to me.

The buffers are easy (and cheap) to obtain?
 
"The buffers are easy (and cheap) to obtain?"
yes very cheap and very easily obtainable, but like most similar japanese ones they rarely wear out.
I would probably go so far as to put a 6 or 12 mth warranty on them,
 
I've got Japan cushions almost identical to these form 2 Water Buffalo's over 35 yr old and they are still like new so one set should last a few life times of Cdo owners.
 
Although it is likely there is no burning need for most of us running street bikes for
such a setup, Id sure be interested. All we need to know is 'how much".
Keep us all posted.
 
I sell a lot of rear wheels for Featherbed based projects, nearly all are not cush drive, but people are always asking for them, this new setup would be a good upgrade for Commando's and be popular with the Featherbed Cafe Racer set. it wont happen over night, usually projects like this, my TZ 4LS brake, 320mm single disc kit for Commando, etc take up to a year to get out there.
 
madass140 said:
I sell a lot of rear wheels for Featherbed based projects, nearly all are not cush drive, but people are always asking for them, this new setup would be a good upgrade for Commando's and be popular with the Featherbed Cafe Racer set. it wont happen over night, usually projects like this, my TZ 4LS brake, 320mm single disc kit for Commando, etc take up to a year to get out there.
Click to expand...

Well, I think the stuff you make Don, is well worth the wait ! When it's available I'll be in line to buy one. Cheers, and thanks for posting :D
 
Well, I'm on the case, the sprocket/drum will be exactly as previous posted pics with standard sprocket
its being cast now, mold making for the hub will start this week and casting of the hub to follow, the cush drive rubbers are being molded now also, when I get the above items finished I'll run off the one piece axles and spacers etc, the plan is to provide the stock looking hub complete even right side hub cover but minus the brake assembly unless people choose to use my alloy brake, so it will be available as hub, sprocket drum assembly with axle, spacers, or even a complete wheel with alloy flanged rim and stainless spokes ready to bolt straight in. A Featherbed version should also be available which will only mean a change of axle and spacers, dont hold your breath, probably 5-6 months yet.
 
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