Cool machine, but it doesn't look like the rider is taxing the 'energy delivery' capabilities of the bike at all. Rider technique and fitness look quite low; for a two minute effort, I'd expect a more linear buildup and hard sprint at the end. Any idea how much power it takes to get the flywheel up to speed? Higher cadence pedaling would be attractive here, I think.

That said, the bike needs to be much more solidly mounted, like forks clamped in a stand, and I'd probably go drop bars so the rider can pull better.