its a mystery david........a solid piece of metal.....not hollow........i suppose it is not original to the bike, but since i only have the frame and had to collect parts for my bike,,,i thought id just leave it there.......the other thing unusual feature is the ends of the swing arm.....they are bent for axle eyelet bolts...........my next powell will be the real deal..........
i like the color....it is an eastwood color and i am very happy with it...........got a deal on the job..........:smile: