ok here is what we did. we ordered the 8.5 by 2 wheels. we replaced the bolts that hold the hub together with longer ones longer by 2.5 inches. then we made a custom plate the fit on those 5 bolts that then attached to our sprocket(secret connection) if you can figure out your own way of connecting the plate to sprocket then the wheel is driven by the hub and not the axel which also means that it can be a dead axel. This is a good thing so you don't have to worry about the critical alinment of the pillow block (you don't need them) your axel can be hard mounted to your frame
greg
