Well I have booked my tickets
£8 from Manningtree at 7:18am (gulp!) to Liverpool Street, gives me half an hour to find my way to the start point (Tower Bridge).
Please will someone meet me at LST and lead me to the start, I'm rubbish at cycling in London!
There were no bike spaces on this train, but as the Norwich train guard's van is HOOOOOOOGE (fitted 22 bikes quite recently, including a trike) I imagine this is just because of their silly rule of only reserving six bike spaces per train. So I'll risk it.
Return train ticket anytime from Saafend to Manningtree was £14.40.
So I'm definitely on for this ride, and no making it earlier as the other Advance tickets are sold out!