WTB sprocket-carrier / cush-drive '77-'82 CB750K CB750C


Been Around the Block

I'm looking for the wider chain-line type of cush-drive sprocket-carrier, from the '77-'78 CB750F2, '79 CB750K (-zabc/DOHC) or '79-'82 CB750C Custom. Four lug cush-drive, not the five-lug from '79-'83 CB750F/CB900F/CB1100F etc - not the EARLY type SOHC carrier either. The type to suit the wider chain-line, wire-spoke rear hubs.

It's for the wire-spoke conversion on my "CB900K0 Bol Bomber" - with a '75-'76 CB750F1 rear disc hub, but for the 10mm wider chain-line off-set of the DOHC-4 engines.

Gonna need a spacer or a dished sprocket too, 'cause I'm using the CBX pro-link front sprocket in 530 gauge chain which is about 4.5mm-5.0mm wider off-set than the OEM set-up. Was thinking of the Cognito-Moto style rear sprocket spacer, OR a dished rear sprocket from CYCLE-X/CYCLE-EXCHANGE etc. Either one of 'em will likely mean the sprocket carriers having to be machined down.

I could probably use at least TWO of the things actually. Gonna build a DOHC 750 after this one. Already got a lot of upgrade parts for it. Might as well keep going with that, save a bit on shipping if I can get 'em both from the same place!

So yeah - who's got some of these things? I'd take a drum hub too, & spacers etc - if that's kicking around with the rest of it. I'd prefer the DOHC style rear drum but WTF they're functionally the same damn thing. I just think it's good to play up the DOHC-4 vibes as much as possible.

These things will likely get a bead-blast, new bearings, spacers etc before I use 'em, new shoes etc new hardware all of that. So they might as well be crapped out & beastly looking.

If I find a drum, it might as well be worn out too, 'cause I'd love to see about skimming it out bigger for weight savings, put thicker new liners on some old shoes & have 'em skimmed to fit , run the thing as a bigger diameter.

Somehow I'd got it into my head that the CB750K rear drum was 190mm but it turns out they're only 180mm, hey? Well I was mainly interested in a 200mm rear drum then skimming it out to take some 8" shoes which is 203mm so it's perfectly feasible to skim out 1.5mm from the drum lining surface. THAT would be cool. What's that big? The Laverda rear drum maybe??? I guess it's got a cush-drive on it and everything. Not the cheapest though. And it looks heavy too. But yeah - the 180mm spun out to 183mm-185mm with some extra thick linings stuck to the OEM shoes with bronze rivets. I guess I'd be interested in a CB550 rear drum too, if I thought the 10mm wider sprocket-carrier would fit. I guess the rear wheel could be DISHED but I'd really rather not - I'd rather lace the wheel up STRONG as a #1 priority. And meanwhile adding an extra SPACER for a full 15mm's of off-set, well that sounds like it would look a bit funny. Gotta look into the weight savings, maybe it's actually worth it? Another good one for the 750cc would be the early KZ400 40-spoke rear drum. It's got the cush-drive, it's the same dimensions (better actually) as the CB750 drum, only it's half the weight. Well, I had a KZ650 rear drum at the same time as the KZ400 drum, had both hubs in hand. Don't have the weights anymore I kept 'em all in a coil-back notebook and lost 'em in a fire. But what I REMEMBER is how the thing weighed easily half that of the bigger hub. Mostly due to thinner Iron linings inside, but the overall casting was narrower as well. Narrower cush-drive too, but still the full diameter and with four rubber lugs inside.

ANYWAY - for the time being, I'm gonna try and get my hands on these HONDA parts! The cush-drive (2 of 'em, preferably) and if there's a drum permanently attached to one of 'em I'd snap that up too. Like I say, preferably the CB650/CB750K-zabc '79-'82 version.

I'll pay a decent price. I'm not outrageously cheap. I mean I'm cheap, but.... A REASONABLE price, I should say.



Coast to Coast
I have a crush drive for a rear drum off a 78 CB750 Hondamatic. They have a 10mm offset, is this what you are refering to.

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