Gonna find myself in Glasgow with a spare few hours the week after next and fancied putting the spare time to good use and take the bike with me. I think a trail centre would fit the bill because of it being a fixed length and waymarked but am guessing that the nearest one would be Glentress and around an hour and a half's drive away – does any of you guys have any suggestions of where I could head for which is no more than an hours drive to get to and would give me around 3 hours worth of riding. I have thought of doing some real stuff and am sure there's probably better natural stuff nearby but I don't possess a GPS and don`t want to waste too much time navigating using a map.
Any suggestions appreciated.

Mugdock Park. I've not cycled it yet myself but loads of people do and rate it pretty highly. It's within 30 minutes of the city centre.

Or Carron Valley. It's pretty nice, go round that a couple of times.

Thanks Zed, both seem to to the bill perfectly – just now need to decide on which one!!

I think Carron Valley has waymarked biking trails, whereas Mugdock is just trails.

Yep – that sort of stacks up with what I've just seen – looks like it's Carron Valley. Cheers all!

Mugdock has some good trails.. but chances are you'd probably spend more time looking for them than riding them.. if you can find a local to take you round then I'd go for that option.. some excellent natural stuff to be riding there.. but if its a short trip, then Carron Valley is probably the safe option… only 10km long, i usually spin around it two or three times, the Run Way is much fun, even better since they done some work on it a few months back, which reminds me Ive not been for a while

There's not really enough at Carron Valley to occupy you for 3 hours though. It's a pretty short loop, even if you do it twice. Mugdock too – some fun stuff, but you would ideally need someone to show you round. Glentress and Drumlanrig would both give you a decent amount of riding and both I'd say are about 1 h 20 or so from Glasgow city centre if the traffic's flowing. Probably more worth your while if you've got the time.

Oops Craig – got in before me there :o)

You can always add Meikle Bin ( the big hill / extinct volcano above CV) to a couple of circuits – that will pad the 3 hours out nicely 😉