Axle extenders for mounting FatWheels on multi-speed bikes are currently available in 3/8"-26tpi female threads on one end to attach to the end of the axle, and 3/8-26 male threads on the other end to attach our training wheel bracket. (We will tap out the female threads to 10x1mm on request) This offsets the bracket 1" to clear the derailleur (Usually, only ONE is required, since there is only one rear derailleur).