There are a few comanies(Revell, Tamiya, Italeri, etc) that make harley kits, most of those are in the larger scales 1/9 and above.
IMAI(RIP) used to release quiet a few kits in 1/12, they were good kits, well detailed but not shake and make kits Tamiya does.
The IMAI kits are also easy to convert and make custom coppers out of, but they are getting rare now and hard to find.
Aoshima bought all the licences from IMAI prior to their closing down but doesn't seem to be doing much with them.
HTH.