speedy1984 said:
Hi, does anyone know of the correct spoke size for a 19" rim and MTB hub and qs205 Hub and 19" rim?Both running the standard cross pattern lacing.
There's no standard lacing pattern. You need to know how many crosses per spoke. Cross-1 is usual for hub motors.
The effective rim diameter varies per rim. You need to know the ERD of the rim you're working with.
If you're building a motorcycle, as your parts pick seems to suggest, maybe it's not a good idea to use a normal MTB front hub. The hole diameter won't match the gaping holes in the rim anyway.
How are you going to register your motorcycle?