I can’t say the sprocket is a an excuse more along the line of fact. Not taking anything away from the guy he has skill, but on a stock sprocket he wouldn’t be able to get that much power and control over the speed of the bike at such a low RPM.
The sprocket size he is running isn’t far off from stunt size.
[ame]http://www.youtube.com/watch?v=16tl0gb1_8w[/ame]