Most of the route is ok on a road bike, probably about 90%+
There's an awful lot on roads & most of the tracks are ok too. I did whitehaven to sunderland & on the first day before Keswick there was one section that i found tough on a hybrid, so that'll be one bit to walk for him
Are we talking about the C2C south of the Scottish border? If so there are two signposted routes, one on the road and one off road. Obviously the road route will be fine and sections of the off road one will be possible but not all.
I shall be doing this soon. I will come back with feed back on road surface conditions,photographs,b & B s used.Tyres will be 700x 25 gatro skins Mercian with a triple.Using route 71 and 65? 180 miles in three days then home to Derby.About 320 miles.May increase to 370 if weather good.
Route out line .
Day 1.St Bees to Appleby in Westmoreland 65 Miles.Day 2 Appleby to Northalerton. 55 or there abouts.Day 3 Northalerton to Robin Hood Bay 60 ish miles.
Day4 Witby to Derby .Making it up as I go depends on other riders.