It transfers to an extent. Lance Armstrong marathon PR is 3 hours from what I read, which is a great result for an amateur runner but totally unimpressive for a professional endurance athlete, let alone one of the best in history. I was actually a bit surprised that's the fastest Lance could do and to me it shows it doesn't cross over that well.
I wonder if running crosses better to cycling than vice versa, I think it might cross a bit better because running involves more (pretty much all) muscle groups. On the other hand there might be a lot of technique in cycling that takes a while to learn so idk.
