... need.For the brake we normally send you with drum, if you need a disc brake, please advise us before ... size 2.5/3.5 so if you need size 2.5/3.5, please specify it to us; For 20", 24", ... but we also have size 2.125, if you need size 2.125, please specify it to us; For 28" wheel, the ... the problem that you don't know how to install it does not fit your e-bike. Motor Performance: 48V350WDimention520mm ...