I thought about that too. I'm not sure how big spacing you'd need between gears so the jumps aren't too abrupt. You probably want something like a motorcycle transmission to handle the high speeds. Maybe something like the pinion gearbox but with much higher gears and larger spacing to get you to 200mph at a reasonable cadence.
The front chain isn't moving any faster or enduring any more intense forces than a normal bicycle drivetrain, so it can be replaced by an off the shelf road bike gear set. With a 30-speed drivetrain this could provide a low gear that's about the same as the high gear on a road bike, so it would probably be possible to get moving from a standstill. In the highest gear, you'd be able to go at least 160mph pedaling at the same cadence that was used to set this record. And that's just with the off the shelf components. A custom set of gears could probably stretch out the ratios enough to provide a high gear that's equivalent to the record-setting configuration.
