Abbey-cwm-Hir - the first serious challenge on the Epic/Legend route. The climb is not steep but it is long as it winds along the side of the hill.
Rideventures blog - detailed description of this climb
Elan Valley - very long and watch out for the increasing gradient after halfway. The incline drops after the waterfalls but then carries on for a long drag up to the summit.
NOTE: the 80 mile Legend doesn't do this one.
Parkstile - the forgotten one - everyone heading towards Glascwm has first to get over Parkstile. Just around the corner the road rears up briefly for a 25% ramp and then climbs more reasonably to the summit a mile further on.
Glascwm - the stats don't tell the story - this is almost entirely 25% straight up so very daunting and usually scattered with cyclists walking up. Watch out for a final ramp just around the corner at the top.
There are 4 more hills to go over:
2 before the "majors":
B4355 - first hill comes after 13.5miles, takes you out of the valley to give you a first taste of the highlands:
David's Well - you'll hardly notice this long, gentle rise back up into the hills:
And 2 after them:
B4594 - an anonymous climb out of Newchurch which will be hard if your legs have gone...
B4355 - long final climb before an equally long descent home to Knighton:
Llanbister climb - very steep immediately off the main road and up through the village. Watch out for the cattle grid halfway up.
NOTE: this one is just for the 45 miler
Fron Goch - a long final climb for the 25 and 45 mile routes, before an equally long drop down into Knighton and the finish.