I've been off the bike a couple of weeks due to injury and as such I'm really bored and just collecting maps of rides I want to do! Does anybody have a gpx (or similair) file for each of the Marin and Penmachno trails that I can steal please?

I don't have them on file but its unlikely you'll need them they're both very well marked trails.

Aye I've done the marin, just fancied a gpx of them so that I can try to make a route to connect them, I can do it on an OS map, just fancied mapping it on google earth!

Start at LLanrwst car park,follow marin until the road crossing after the dragons tail,turn right down to the ugly house,across the river turn right,turn left at capel tan-y-garth,tech climb over to dolwyddelan-DO NOT TRY RIDING BWLCH Y GROES-unless you like knee deep bog death marches-cross river left past school and follow railway to tan aeldroch,right up past ty mawr until you cross loop2 of penmachno,quick lap of machno til you rejoin where you started,retrace route back to tan aeldroch but cross river ,left to pont y pant,turn right and follow sarn helen, over the miners bridge,straight across road until crossed by marin trail,follow marin back to car.80.3km and a lot of climbing.One of my regular rides-takes me 5 1/2-6 hours on the ss.Enjoy.
Can always come off at Cyffty Tube and go llyn geirionydd,llyn crafnant,roman road to capel curig then ugly house etc for a bit extra.