I'm thinking of giving this a go this year (Whitehaven to Sunderland).
What type of bike did you take? Was it pannier'd up? Reading the website set up with lots of info http://c2c-guide.co.uk/index.htm the off road sections sound fairly demanding for road/touring bikes. They don't sound too fun anyway without a mountainbike or decent tyres. I don't really want to miss them out either given half the route is off road! If its over summer, I guess low tread summer tyres would be fine for the road sections too, and keep travelling gear to a minimum?