1980 Yamaha XJ750 chain rear wheel replacement?

[Wired1]

Does anyone know of another chain drive wheel that will easily replace a 1980 Yamaha XJ750 shaft drive rear wheel?
Ideally with the drum brake setup the same so I can reuse that as is - so probably another Yamaha wheel.
Bit of a long shot but I thought I may as well tap into the brains trust here lol...

[T.W.R]

It can be done on XS models...not sure about XJs though
caferacer.net would worth checking out

[biggo]

What are you trying to achieve ?

You would need different swing arm from a chain drive bike and motor/gearbox from chain drive bike some of the smaller XJ,s are chain drive but not sure how easy to swap, might be easier to buy a chain drive bike ?

[AllanB]

Might not be hard as thought - I have a feeling (scratching my memory here) that the XJ initial output was effectively a shaft suitable for a sprocket with a conversion for 90 degrees into a shaft. Or I'm completely wrong.

[biggo]

Might not be hard as thought - I have a feeling (scratching my memory here) that the XJ initial output was effectively a shaft suitable for a sprocket with a conversion for 90 degrees into a shaft. Or I'm completely wrong.

Hi Allan.

Quote from XJBikes forum.

To make a long story short, it is not practical to convert an xj 650, 700, 750, or 900 to chain drive. You would either have to swap engines with the 550 or other bike, or re-engineer the trans shaft and engine cases. Unlike the 1100, the other xj's have the middle drive unit actually made into the engine case.

[Grumph]

Besides the problems converting an engine to chain drive, shaft drive frames have the rear crossmembers in the wrong place...
Invariably they have a crossmember above the swingarm pivot - which is too close for a chain drive.
Major work....

[Wired1]

Yep too hard. I hadn't considered the swing arm issue so thanks for pointing that out

I was looking at a bike on Turdeme that would make a good donor for an electric bike conversion but for the shaft drive.
Ideally it needs to be a chain drive. I will keep looking

[husaberg]

Yep too hard. I hadn't considered the swing arm issue so thanks for pointing that out

I was looking at a bike on Turdeme that would make a good donor for an electric bike conversion but for the shaft drive.
Ideally it needs to be a chain drive. I will keep looking

Why the electic motor can be mounted in either inclination, unless you are worried about the torque reaction?
Personally If you are going an electric conversion i would look at using a CVT as well.

[Wired1]

I've seen a few shaft drive conversions and they have to add a half shaft to get the gear ratio right plus to centre up the motor. The electric motor sits nicely side on and the sprockets work well that way around.


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[Wired1]

What's a CVT?


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[Honest Andy]

What's a CVT?

perfect come-back

[husaberg]

What's a CVT?


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you jest, A Constantly variable transmission

[Honest Andy]

No, surely YOU are the jester.... electric motor doesn't need a gearbox...

[Honest Andy]

Although I suppose you could carry one on the packrack... as a spare... just in case...

[husaberg]

No, surely YOU are the jester.... electric motor doesn't need a gearbox...

Yes i am aware of the torque output curve of a electric motor, while it doesn't need one, i believe would be better for real world operation with one.
Remember the efficency of a electric motor is considerably lower at lower loads and lower speeds.
Peak efficency is the 80-100% load range.