Exactly how much up hill is there, we're looking to head out for a couple of weeks of DH and im meant to be doing this. One of the lads did it last year on a V10, however he's pretty fit. Im not. Slightly worried i might die.
I did it on a very heavy Big Hit last year, with no granny ring, too-soft a spring and a short seatpost.
It was very hard work in many places, but I got round most of the 75km (we accidentally cut off a section in Switzerland by getting on the wrong lift). I'm not very fit.
To be honest though, the bike was massive overkill for 95% of the course, so it wasn't as much fun to actually ride as it should have been.
I'd probably have preferred my 6in bike for a lot of the riding we did the week after too, even though that was mainly DH runs.