Rear cush

Pulled the rear wheel on the 74 850 and had a look at the cush rubbers. They have about 10k on them are still tight and in good shape no slack at all. Granted I am not a downhill racer but I do use the back brake.

Better than what I found after 40,000 miles...

I always thought that this was such a cheesey design. Does any other motorcycle use something similar??

Was it not a stop gap sort of quick fix for gearbox troubles? MkIII did sort this out which gives credence to the supposition.

I saw on FB that Madass140 (Don Pender) has a new batch of his rear hubs with cush drive available. Not a cheap fix but does look lovely.

I needed a new tyre but I wanted to get the "right" size rim for it (2.5 inch) but I didn't want to take the bike off the road while I waited to get the wheel rebuilt so looked at buying another hub too. So I bit the bullet and bought one of Doms.

...in effect the most expensive new tyre I've ever bought.

Nice result at the end of it though and I did have some bits to sell on after.

Can you tell the difference compared to the original hub?

Pix attached...there is no comparison in the amount of cush area!

Gadge said:

Can you tell the difference compared to the original hub?

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No, not yet. I only did the wheel change two weeks ago. The original type smaller cush rubbers were showing signs of wear and weren't very old.

To do this conversion, I am guessing that you need to change the hub, drum, and go with the solid axle? What kind of $ in total??

Stephen Hill said:

To do this conversion, I am guessing that you need to change the hub, drum, and go with the solid axle? What kind of $ in total??

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Yes, hub, drum and spindle. $450 plus shipping I think . Shipping to UK was a bit steep but it is what it is.
Add in the cost of a wheel rebuild too!

The only problem is that it gets expensive... Don has it all worked out. It certainly makes no sense to upgrade the wheel hub, and lace a 19" steel WM2 rims and put a 100/90/19 tire on them... It only makes sense (to me) to do the whole thing. Buy Don's new cush drive hub and 1 piece axle, then lace up wider aluminum rims to accept a more modern tire.

You end up with a bulletproof axle, a real cush drive hub, lighter unsprung weight on the wheel, and better performing tire shape in contact with the road....

.... but that also means you'll want to swap the front tire's rim for a wider aluminum rim as well to get similar performance up front. The money adds up to do the whole package, but lighter unsprung weight is probably one of the best things you can do to improve your bikes handling, to say nothing about the better performing modern tire profile improvement you get as well.

You could do front and back separately and space out the expense, I suppose... but I doubt anyone does that.

I went with a 19" WM3 SS wheel on the back. Stock on the front.

Where does the weight saving come from??
I recall reading some time ago that there was not much weight saving on aluminum rims vs steel.

Stephen Hill said:

I recall reading some time ago that there was not much weight saving on aluminum rims vs steel.

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A flanged alloy 1.85" is 1.77 lbs lighter.

Stephen Hill said:

Where does the weight saving come from??
I recall reading some time ago that there was not much weight saving on aluminum rims vs steel.

Click to expand...

Certainly no weight saving on mine, quite the reverse, I went from 1.85 inch alloy to 2.5 inch alloy.