CB750K Rear Hub

[MikeSB6]

Hello Folks,

     I'm thinking of fitting an accessory swinging arm into my cafe racer project and have one available. Unfortunately, it's for a Z900/1000 and is narrower than the standard K arm, so when the hub is fitted, the bearing housing on the sprocket carrier pushes the hub about 1/2" to the right so it doesn't align centrally with the swinging arm. However, about 1/2" of the housing is for the bearing retainer plate and the oil seal, so I was wondering about machining off this section of the housing to allow the hub to move to the left. The bearing is retained from coming out of the hub by the axle spacer and I could use a sealed bearing. Has anyone done this before, or is it completely bonkers?
   
       Cheers, MikeJ

[r1_pete]

It could work, but, you would weaken the bearing housing by machining off the overlap, you would also need to use a sealed bearing.
What bout chain run? Have you checked that would be straight.
I think I would try a matching Kawasaki hub before machining the Honda one.

[Trigger]

Seems like a shed load of work that may not get a good result. I would sell the 900 swing arm and look out for a Dresda arm for a CB750.

[K2-K6]

We are unaware of your machining capabilities but as already posted it seems relatively involved to do it the modded way if there is a more straightforward route that can use parts in standard configuration.

https://carpyscaferacers.com/cb750-cross-drilled-boxed-swing-arm/

Maybe sell the Kawasaki specific arm and use something like the above.

[matthewmosse]

Also you do need to check carefully the internal structure of the hub, I have machined a few old motorbike hubs down for random jobs and found that there is a lot more air and less alloy then I would have thought in some hubs, I'd be looking to either get a swing arm that fitted better or a wheel to fit the swing arm, either way it's low cost if you sell the surplus part. Modify your current hub and it radically lowers that parts value.

[MikeSB6]

Hello, and thanks for the replies,

        on second thoughts, I can probably get away with spacing the sprocket and offsetting the rim, as the measured offset is only about 6mm, which will save quite a bit of work. I've checked the clearances and doing it this way should allow fitting of the hub,

             Cheers, MikeJ