Any ideas?

[RichardL]

The guy on the front is actually wearing a period cycling jersey and they are sitting on the banking of a wooden boarded velodrome cycle race track.

I wonder if the crew of two was something to do with the requirement to pace at a very constant speed i.e. controlling the engine revs was virtually a full time job.

Also, it seems, the rear persons back provided wind shelter for the cyclist.

Evidently, chosen for the job due to his particular body shape.

Richard L.

[Rex]

I think the two-person pacer would have been more down to the complexity of controlling the engine to a constant velocity than using the rear person as a wind-break. It didn't take long for the Derny to develop enough that the driver alone was sufficient, and that's how it was from then on.

[muskrat]

G'day Fellas.
That clip of Guy Martin would have been scary for him. On sandy beach, hit a bit of driftwood 
Here is what he could have done on a salt flat https://www.youtube.com/watch?v=6CFTqHbgsKs
Cheers

[BagONails]

That's insane Musky, the gearing on the bike must be ridiculous.  Noticed she had a much better aero pod to tuck into with sides, whereas Guy just had a brick wall effectively and much more turbulent air to contend with.  Boy you have got to have some faith in your pacer!  At the end it looks like she dropped the tow while they were still motoring at quite some speed