ET: Engine (Twin) Engine Shock Absorber

[Chris Launders]

This is slightly off tangent but possibly relevant to the ESA topic. My Brough does not run an ESA but a cush in the clutch (Norton) and back wheel (Enfield), the back wheel has the sprocket one side and the drum the other but the later Enfield wheels have a drum/sprocket on the drive side and just a spoke flange on the other side.

So I wondered about fitting the later drum/sprocket type hub , pressing the other spoke flange off and fitting a spoke/drum flange to take a Vincent drum, giving drums both sides, and what were the chances of this contraption fitting in the back of a Vincent.

Well, very good actually, the post war early heavyweights have a 7" drum, same as the Vincent (so a Vincent brakeplate could be used) the chain line is about 1/4" out but the hub could be mounted offset. The Brough drum uses the same flange dimensions as a Vincent other than 6 bolts instead of 5 and has the same inwards taper (for the spokes) so a new flange to take the Vincent drum is easily made and fitted (the cush unit and spoke flange are pressed on, not one piece or welded)

For cheapskates the Bullet hub uses the same cush unit but has a 6" drum and smaller diameter hub so you would have a 6" and a 7" drum and couldn't use the chain side Vincent brakeplate, but they are available new, cheap, complete from India.

 

[bmetcalf]

"Bespoke cush drives made for any motorcycle " claimed here:

http://www.normanwhite.co.uk/misc.htm

 

[vibrac]

Royal Enfield cush rear hubs go back pre war they sold the wheels wholesale to Panther and Scott amongst many others. In fact when I was rebuilding my 3 speed Scott (It had a wheel but no drum) I was so put off by the cost of the ribbed rear brake drum that I used a Vincent one! The 6 holes were on the same PCD as the Vincent so I had one through bolt and four bolts into a common spacer held by 5 bolts from the RE hub and the extra rib caused consternation with the Scott rivet counters (Of which there are thankfully few)