I came across this downhill course while I was walking the dog. It's not too extreme apart from a couple of avoidable jumps near the bottom. Easily reached from the car park at Carberry and, as far as I can tell, open to all. Perhaps a closer alternative than Innerleithen for those wanting to give it a try.
Downhill mountain bike trail in Carberry Woods by Cycling Mollie, on Flickr