The center hole is about 3 1/2
bolt pattern is 4 bolts about 4 1/2 dia
The same Hubs are on a b1550,b5100,b6100and b7200
I think the rim is used on the b1550 and the b7200e
the b1550e wheel is 66414-57620
the b7200e wheel is 96018-45110
BUT both wheels have the same r and l rims same bolts and...