why do the CPracing wheel adapters(4x110 to 5 lug) require the use of disc brakes?

 

Most likely because of the offset for the rear wheels would have to be considerably smaller than the fronts. It would make buying wheels alot easier. That is just a guess but there could be some other clearance issues.

 

cause drum brakes suck? lol

 

think I figured it out. the CP adapter uses a stud on the backside of the adapter as the 4th hub-adapter mount, which bolts to the axle with a nut on the inside of the axle flange. I think it is as simple as the fact that there is not enough room on the inside of the drum assembly for the nut to spin with the axle. if that makes sense.

 

....and the minor detail of the backing plate being in the way.