On holiday in the summer I did a round trip from Newquay to Padstow and back which was only about 35 miles and found it much harder and took me longer than the London to Brighton 54 miles I had done a month earlier!
Here in Hampshire I forget the hills can be so endless.
I aim to do a 100 miler this year but not this one!
The piece of road from Bude to Tintagel is awesome. Think the 33% may be along this section some of the roads are so steep I don't know how they got the tarmac to stick! It does literally follow the coastline.
There's a nice little cafe at Crackington Haven if you need a rest.