Its busy as Hell. Classified as the “tourist” track to the top of the Old Man. It is usually full of walkers all of varying ability. The pics are of the best sections. The upper section down from the summit is rocky as hell. I wouldnt advise it at all.
If you hell bent on doing the summit then the ridge route to Swirl How is probably a better bet, then descend Prison band. From there you can either take the path past Levers water or ascend Wetherlam and down Lad Stones back to Coppermines quarry. This descent is probably the most feasible on a bike.
Although you aint going to be doing the sport any favours going around on those paths at anytime other than midnight.