I'm an American transplant in London and have lived here for two years. Back in the States I loved riding my mountain bike on the weekends. I haven't been able to do too much riding here because while I live in East London, I spent the last 20 months working in Marlow which meant a two and a quarter hour commute via tube, train and bus.
I have switched jobs and am now working in Covent Garden and have been commuting by bike for the past month. I absolutely love it and try to get more rides in on the weekend to see more of London and the area. I'm currently putting 80-90 miles a week on my bike and haven't needed to top up my Oyster card and look forward to not doing so for a long time.
Lots of good information here. I'm off to learn more and find recommendations as to how to best use my company's ride 2 work scheme.