MartinM wrote:
Simon Brooke wrote:

As it's an 'out and back' course there's obviously no net
climb

but still climbs and falls en route surely even if it ends up at
the same place.

Theoretically any amount of undulation works against the rider as you
can never quite get back on the downs what you lose on the ups.
However, there is, or at any rate used to be, a small degree of freedom
in what exactly constitutes "out and back". The fast F4 course I did
most of my 10s on as a schoolboy started from a slip road onto a dual
carriageway near the top of a longish hill that was steepest near the
top. The finish was by a road sign in the opposite carriageway but was
about 200 yards short of it. So the start was a short, steep, downhill
sprint followed by a long gentle downhill, then a longish flat bit,
while the finish was a longish flat bit followed by a long gentle
uphill, followed by almost no steep uphill.

--
Dave...