Give that man a cigar. Nothing better than skinning a few superbikes on something that really shouldn't
Look how low the bike rides (seat height etc). Unlike our superbikes where we often sit on top, this guy is sat 'in' the bike which helps tremendously to keep the cofg as close to the track as possible thus doesn't give the impression of tipping in to a corner. Great for confidence building, high corner speeds and why go carts corner so well without coming unstuck!
Looks like an 883 or something ... which having ridden a pals I can tell you they're completely and utterly gutless !
Look up National Motors on that instagram thingy or YouTube.. They have some great skills riding the way they do, that Harley was hugely modified, I find there videos compulsive viewing and funny to watch, always chasing down rather faster tackle.