We have booked Bryn Gollau the Solihull MC club hut which has 17 beds. The hut looks like a corker (see here) The hut is well situated for the Arans, Dinas Mawddy, Cader etc etc loads of biking as well as walking and climbing in the area
Forgot to add the instructions for locating the hut!
(Copied and pasted from UKC)
Dinas Mawddwy is on the A470 close to Dolgellau. Leave the A470 and go through the village past the Red Lion Pub. Continue down the hill and park on the common land just before a bridge. Cross the bridge and turn left towards the campsite then immediately right on to a footpath. Follow the footpath up the hill to a track and turn right along the track. Bryn Golau is in the top corner of a field to the right of the track.