This is a very technical trail only to be undertaken by very experienced riders.
You are advised to be riding a full suspension bike to attempt this trail. It is described by British cycling as, “you should expect to come across unavoidable trail features such as jumps and drop-offs that are not rollable at slow speeds. High levels of fitness are also required as you don’t want to be pushed to your limits physically when your technical riding skills are being challenged.”
The “black” trail at Grizedale is a short descent (It takes about 2 minutes to descend) starting near the top of the first singletrack climb on the North Face Trail. Just carry on straight at the fire road junction past the second singletrack section of the red on your left, you will find the black on your right of the fire road after a few hundred metres. It has a range of doubles, triples, step downs, berms and small drops.