Shaft diameter on 3kW motor

[ScottBlake]

I'm looking for sprockets that will fit the shaft on the 3kW motor. I can't find any 20mm bore with a 5mm wide keyway.

[Bikemad]

Hi Scott andto the forum.

A quick Google search found the following:

14T 20mm bore 5mm keyway

20mm Bore Sprocket 13T For #428 chain

13 Tooth Sprocket (20mm Bore)

What pitch chain are you planning to use?

Alan
 

[ScottBlake]

Thanks for the links Alan. I'm in the US and 20mm does not convert to inches cleanly like the 5kw motor 22.2mm equals 7/8 inches common size. I also kept finding 20mm diameter stuff with 6mm keyway? I'd probably use #35 chain because it is easier to find sprockets and attachments for 1 inch rear axle. I like the 13 tooth sprocket from Maxi-Pro. Do you know if they ship to the US or can you find other suppliers?

[Bikemad]

I like the 13 tooth sprocket from Maxi-Pro. Do you know if they ship to the US or can you find other suppliers?

I don't know if they will ship to the US, but a simple email should give you the answer:
sales@maxipro.com.au
info@maxipro.com.au

It might also be worth contacting a local sprocket manufacturer in the US and see if they can bore out an existing 3/4" sprocket to suit a 20mm shaft.

Alan
 

[ScottBlake]

I got a 5kW from Golden Motor, and it works great (I will try to attach a photo of my electric trike to this message).

I really want to get the 3kW motor for a smaller project, but that 20mm shaft is holding me back.

Maxipro does not ship to the United States, and the other links were for 428 pitch which is hard to find chain and rear sprockets in the US.

Another problem I found is the ISO Metric Hardware Specification tables show a 20mm shaft should have a 6mm keyway, not 5mm.

13mm to 17mm shafts have 5mm keyways
?18mm to 22mm shafts have 6mm keyways

I might ask my local suppliers at surpluscenter.com or staton-inc.com if they can make a custom sprocket, but I feel silly paying extra for a small basic part.

Do you know what other people have done with the 3kw motor 20mm shaft?