Nice ride from Water Grove reservoir to Calderbrook. Steep descent into Bottomley, tricky on the switchback bends. Climbing from Walsden the bridleway became less defined and shortly after passing through a gate it wasn't clear which route to take. After taking the right fork and through a gate the route went west up a very steep ascent (~24%). Amazingly I managed to climb it, albeit with a few stops, in bottom gear and turbo mode. Met two MTBers at the top by the Trig point. Continuing west for a stretch then south, the track disappeared on the gound. Followed the other MTBers, who I thought knew the terrain but actually didn't, we went down a steep hillside (~33%) to rejoin the track to the south west. The track then became more scenic on the return to Water Grove.