http://singletrackworld.com/forum/topic/penmachno-trail-details-anyone
and what I said there….
Obviously seem to be in the minority but: the worst trail centre trail Ive ridden and not worth the effort when there is far better natural and man made near by. Went up there a couple of weeks ago for a midweek break, did penmachno, CyB Beast and the Marin at Betwys. Not a single section of the Pen is memorable for the right reasons, but there are loads of bits of the other two that thinking about makes me smile now.
They also seem to have an issue with trail build/design and water. A significant proportion of the second “loop” at Pen had deep standing water on it. When you build an all-weather trail out of hundreds of tonnes of aggregate you end up building an impervious stream bed, and if you dont manage it it will hold water. We got soaked through on Penmachno, yet finished the Beast which is twice the length bone dry and almost totally clean. Same for the Marin. The Marin is a bit old-skool trail centre fireroad-up-singletrack-down, but the quality of the singletrack just gets better as you get further around it.
Its definitely worth taking a bike to “the area”, but its the worst built trail in the area IMHO.