Beecraigs has some nice singletrack – a little difficult to describe as the stretches are all quite short and you need to go back on yourself quite a few times to get the best out of them. Suffers a bit after a lot of rain which is a pity as most of the bad bits would take very little work to improve. Hard to get lost so just go and explore. WLC have recently announced that they intend to lease some of the forest to ‘Go Ape’ which I cant say I’m over enamoured with given its small size and the current managements rather backward approach to ‘accommodating’ mtb’s (removed all the waymarked signage)
Muiravonside has a really nice singletrack loop (best accessed from the canal as suggested above) and you can link in with the Avon heritage trail which is good in parts and totally sh1t and ill conceived in others. Best continous stretch leads back from the Aqueduct at Muiravonside to Linlithgow Bridge.
Both parks can get quite busy with folk out for a walk so best early a.m or late p.m. Muiravonside same story but also with the added spice of a phantom log placer whos antics get a little tedious. All he or she is succeeding in doing is widening the erosion on the trail as folk go round the obstacles.
You can link both parks with a little imagination, the canal and/ or some road.
Another loop is to head East from Lithgae on the canal and follow the NCN to Abercorn church, through the graveyard and West above the shore to Blackness. There’s some nice singletrack from Blackness to Boness along the shore then a bit of a grind by road to Grangemouth, up the back of the ski slope at Polmont then back along the canal