I've just finished this for the second time. It's a quiet incredibly hilly route, the worst climb being the third on Strines Moor maxing at 26%. Bike was Thorn Raven Tour. The bike has done about 5500 miles by now. This was my third tour, and longest one on it. 1050 miles approx. Endless climbing.
Problems on tour. Zero! No puncture, no mechanical problems, superb changing. The main problem was listening to the grind crunch expletives of derailleur equipped fellow tourers on the steep climbs! Two other cyclists were on new Roberts Rohloff-equipped bikes and they had zero problems also.
I did this tour on a derailleur bike last year and it was a close-run thing that the bike wasn't cast into the briny wastes at JOG.