The primary purpose of the HD Hubs offered by Grubee is to get the mounting of the motor driven sprocket off of the spokes and onto the hub. Mounting the driven sprocket by clamping it to the spokes is a less than ideal solution, and causes alot ofspoke brreakage issues for many builders. The reason for the two different types of hubs Freewheeling and Solid Mount has to do with the type of motor you are using and weather it uses a manual clutch or a centrifugal clutch and a pull starter. The fact the the motor driven drivetrain has the ability to freewheel is a plus when you are actually pedaling the bike (less drag) but if you need to be able to bump start your motor (Chinese 2-stroke) you don't want the left side freewheel.
ocscully
