Most people will ride it down. Do head down from Ridgemont on Deadfall, you can jump on it the beginning of the trail where Eco Terrorist and Kid's Stuff meet, which is at the junction of Ridgemont Road and Branch A Road. If you want to ride it up, then head North along the Old Stumpy hiking trail (starts next to the skateboard park), across Ridgemont Avenue, and carry on until it comes to a junction right next to the train tracks. A wooden signpost points to Coal Discovery Trail, staying on the same side of the train tracks. Follow that up onto the powerline road and across it and head into the forest - Deadfall should be the third trail crossing it from the right.
Starting at the top of Ridgemont the trail is up for a short while before flattening out in an open section and allows some pretty fast riding. A short section in woods, a bridge and then you head up towards the junction of R Trail, Broken Derailleur and Deadfall. Straight through the junction and head down. Part of the trail is suffering some erosion, with a a deep rut that likes to suck you in, but it's over pretty quick. Signs will point you towards Bridget Fundah, Ich Bin etc. Great fun rolling downhill.