I think he's looking for a center to center measurement for the bolt pattern on the 4 lug wheels. All I can offer is that they're in a square. If it's any help, I think they also have the same spacing as R100R and R100GS paralever hubs. Are you making a spoked hub?
what I'm trying to find is a wheel hub assembly that will accept the rear wheel so I can use it for a sidecar and have matching wheels and then when I get a spare, it can match and double as the pusher tire or the sidecar tire. It may also be something the same as a car has so then I can run. (Gasp) car tires for my pusher and hack tire. I didn't want to post sidecar shit in this forum, but it kinda has merit. It is an airhead.
