Wharncliffe is very good if you like DH/enduro type stuff but you’ll do a lot of laps in 5 to 6 hours. Similar for Parkwood so I assumed you’d be looking to get out into the Peak.
Just been downstairs for a look at the VG book. It does have both the links I mentioned and suggests routes to join to once you’re out of town.
I’d be looking at out through the parks, up the bastard (porter clough) and over to Redmires and Stanage Pole. Down the plantation steps, back up the dale and over houndkirk moor. From that point you can cut left through blacka and home via Eccy woods. Or if you’re still keen there are add-on loops further south. Longshaw estate then Totley Moor back into Blacka would be good. Beyond that you’ve got the Froggat/Curbar permissive bridleways but it’s a long way back into town.
All depends how fast/strong you are 🙂