Well as I planned a short while back, I took a train from Raynes Park to Horsley and cycled to join the RideLondon route as it headed away from West Horsley thru Newlands Corner, Abinger Hammer, Forest Green, Leith Hill, Dorking and Box Hill and continued to follow it thru its planned route back to Wimbledon. Have now done a significant portion of the 100 mile route save for the central London bits.
Newlands Corner is definitely the first significant challenge, but while it is steep it didn't seem to go on very long, or maybe that was my imagination as it was quite straight. The way down was fun!
Leith Hill is a nightmare! I had real problems here, had to stop halfway and get some refreshment down me. I doubt it will pose too much of an issue to the fit and ready hardcore amateurs, but to those doing this for charity with lesser experience or fitness its going to be the hill which finds them out. There's going to be a lot of walking with bikes here I think. Oh, and the downhill part is epic. I managed 37.9 mph according to Strava, 38.1 mph according to everywhere else.
Box Hill was the lesser challenge of the 3 grade 4 hills IMO. It looks daunting as you approach it from Dorking, but its a pleasant gentle grind. There's a couple of bits which gets a little steep, but having done the other 2 hills plus 25 odd miles by this point I didn't have an issue with Box Hill. Of course I was gently pushing thru it, if I was actually racing like a lot of folk will it may be quite energy sapping.
Had a lovely lunch at the top then carried on the RideLondon route back to Wimbledon, then home.
Was VERY pleased with the 13.5 mph average speed considering the last time I did a 55 mile route I took in no grade 4 hills and managed 12 mph. Cadence seems pretty stuck at 70, my average heart rate also pleased me, dropping down to 156bpm versus mid to high 160's.
Weather became clear and sunny at the top of Box Hill, but prior I got a bit of rain and was quite windy on occasions, I got pushed sideways at one point which hasnt happened to this extent, that certainly woke me up!
I'm definitely making progress and feeling faster on the flats too. Hill climbing really needs work though.
http://app.strava.com/activities/48970852
Few pics (iPhone....sorry)
Newlands Corner View
Leith Hill summit (boring I know)
Box Hill View
Will post some of these details in my RideLondon thread too.