Cassette hub / changing wheel size

[stormdot5]

I've been looking into some of the cheaper ebike conversion kits. I've noticed most seem to not list the specific components, and those that do often have freewheel hubs. Can anyone point me at the cheapest ones that accept cassettes. These would seem to be simpler.

Secondly. Has anyone had any experience with re-lacing a hub motor into a different size wheel. I understand it would affect top speed depending on if you go up/down. Not many seem to come with a 27.5" option. Would this have a noticable effect on acceleration?

Thanks for any help

 

[trex]

if you have 8-speed cassette then it's a lot simpler to get an 8-speed freewheel replacement.

...
Not many seem to come with a 27.5" option.

woosh have front and rear BPM and rear SWX02 motors in 650B

...
Would this have a noticable effect on acceleration?

yes.