the photos deceptive i think because the pedal is past the 6:00 position... so while his leg is not extended in the photo, at the bottom his thigh would probably still have the standard 30-35 degree angle.

But if not his seats kind of up there as it is, could maybe just use a bigger bike

He might have a knee or even hip problem that makes this more comfortable.

I'd have to see a video to tell for sure ... I don't think that right leg is completely into the 6pm position, either.

But in this case, 1/250, based on the specs for the photo.

He might not be going all that fast, though - if you focus on your subject, then move your camera along with him/her/it, you can get that interesting background blurring (but with the proviso that, if you're like me, a lot of the photos won't come out all that well).