Topic: Cush drive compatability

[evanphi]

Changed my rear tire yesterday, and in taking off my sprocket, I found that my rear cush drive rubbers are from a Hondamatic! COOL. Makes sense, as the rear wheel is a 17"... BUT they are falling apart...



The Hondamatic rubbers have the big one and small one joined together... and since mine are falling apart I would like to get some new ones. Can K model rubbers (one big, one small) fit the hub? The hub on the CB750A and the CB750K are the same (PN 42601-300-050), but the flange for the sprocket is different. CB750K PN = 42609341000, CB750A PN = 42610393000

No direct pic, but from the splines under the sprocket bolts (not round, like on the A), it looks like the flange under my sprocket is a CB750K one... (zoom in!)



I am thinking I can use the K rubbers, but I just want to make sure.

[evanphi]

Bump. Anyone know?

[oldhatt45]

evanphi,

Can you measure the flanges that contact the cush drive rubbers on your sprocket carrier?  (Maybe include a picture?)
I am about to put my rear wheel together (750 K6) and could take some measurements and pictures as well to help you out.
I have the standard K model rubbers and sprocket carrier and can measure them as well. 

Charlie

[evanphi]

I wish I had done that before yesterday! I assembled my rear end last night and took it for a rip. Next time I plan to have it all apart was going to be next winter when I do bearings.

[evanphi]

Hmmm... Some detective work...


F2 (comstar wheel), and K7-8, use the same sprocket holder as the Hondamatic, and they use the same all-in-one dampers.

F0-1 bikes (spoked wheel, disk brake) used the same dampers AND sprocket holder as the K1-6 up to SN: 1025911, and then from 1025912 onward use the same DAMPERS as the Hondamatic/F2/K7-8, but no change in the sprocket holder is mentioned...




Because the only difference on the F0-1 is the dampers, and NOT the sprocket carrier or hub (no mention on CMSNL), one would assume that they could be swapped between any bike K1-6 or F0-2?




Did they just change the manufacturing process for a single rubber piece?

OR did F1s after SN: 1025912 come with comstar wheels, and thus the necessary change to new dampers?