you aren't the only one who didn't know what tubs were TD, its just that most got their teachin towards April/may this year as Candy went thru what he was using for the rest of the seasons races.
As for descending the HH at 55mph + I am sure FB could get to his speed and be very safe on that piece of road as it was smooth and open, the only blip was a road change over a kerb rise, nothing too bad.
Personally I thought trying to feed while descending at 55mph was fast enough with one hand ;-) haha