If you've never done it, my favorite ride when I was testing the Commando was to go up the old A6through Lancaster and Carnforth, then head west on the A590 from Levens Bridge to Newby Bridge. From Newby Bridge, head over to Broughton-in-Furness then towards Ravenglass. Just before Ravenglass, there's a single track road that heads over the fells to Ambleside. It goes over both the Hardknott Pass and Wrynose Pass - great riding country on a good bike.
For a fairly easy day out from Manchester, you could head back from Ambleside, through Windermere and back to Levens Bridge for the A6 (or the M6!)
I used to take another "white" road out of Ambleside that joined the A592 to Penrith. From Penrith down to Scotch Corner, then the A6108 through Richmond. Since I was headed back to Wolverhampton, I'd take the A684 to just shy of Aysgarth, then head south through Kettlewell to Skipton. From Skipton, I usually took the main roads through Burnley, Rawtenstall, Ramsbottom, then round Bolton to Wigan and back south on A49 to Shrewsbury, A5 to Telford and then through Shifnal and Boningale to Wolverhampton. That was "all in a day's work", about nine hours altogether and about 490 miles, I think. Great fun, and I was getting paid to do it and getting the petrol to do it on paid for.