Depends what kind of riding your after. The terrain in West Lothian is more suited to XC riding rather than steep gnarly stuff. On the Beecraigs perimeter you have Witchcraig above the Korean war memorial which has some steeper descents on the North and East Side. A few miles North West you have Wallaces cave and the Avon Valley Trail which leads on to Muiravonside. Country Park. Both have lots of singletrack and hidden trails which you can find just by looking around. There is The Desert just North East of the Westfield/ roundabout which you can access at the roundabout layby. You have Ravencraig Woods just down from the Noc hill (Highest point in the Bathgate hills) which has lots of singletrack. Too much to mention here other than you can link lots of trails to make a Giant loop. Northwood just across from the old Bangour village hospital has trails that can be linked up to make some decent riding as well.