I've done it all in one day. As Trio says its not really technical and the gates aren't too bad once you get away from the Rawtenstall area.
You could ride it on a hardtail, some of the people in the group I was riding with did, however they both had springy Titanium frames, I personally wouldn't have like to be on my harsh ally hardtail by 40 miles. I still rate riding up the cobbles of Rooley Moor road into a stinking headwind 42 miles in as one of the most lower back destroying things I have ever done and I was on a full-suspension with 5 inches of travel, the hardtail riders were not smiling. If you've only ever ridden a hardtail you'll not know any different.
I did it clockwise, starting from Clowbridge (sp?) reservoir which is near Rawtenstall (I think). The trail conditions are generally pretty good though there are some muddy sections, I don't remember many though and it rained heavily just as we set off. A lot of the tracks are quite "fireroady" and become draggy, porridgy and very abrasive when wet, though nice and fast if dry. When we did it our group went through three sets of brake pads (not all from the same bike), I always carry spares now.
It can be quite remote feeling, I'm not sure there is any easy place to replenish water etc without adding quite a few miles on (this obviously depends on where you start from), a friend of ours hid some water near the bottom of the Rooley Moor road for us to top up.
My top tips would be
1) Plenty of fuel, water, spares for the bike etc, clothing, need to be pretty self sufficient
2) Don't do it in October (likely to throw it down as soon as you set off, then sleet on the first exposed moorland!)
3) A small well matched group to ride with, we had a group of about 9 and it just multiplies the potential faff/mechanical factor immensely.
4) Keep going at a consistent pace, we faffed around a hell of a lot in the first couple of hours mainly because at food breaks the lads were a nightmare to prod into moving again (too busy talking absolute twaddle), we paid for this later by having to hurry, daylight hours aren't the longest in October!
Hope that helps a bit, I would definitely do it again (when bike fit), but it would preferably be in summer with no more than three other people.
