You sound much like me a long time ago except you were/are clearly a faster runner (more focused on shorter distances) and already as fast or faster biker than I ever was. FWIW, I pretty much never raced on the track and rarely raced less than 10K (34:50 10K PR and 2:42 marathon PR although I'll swear that I had a sub 2:40 in me in 1984 until it turned up super hot).

My judgment is that it takes 6 to 9 months to pretty much get your 'bike legs' to mostly (not completely) there. In no order here is what I observed when I transitioned.

1) The general training principles are the same

2) Biking requires a MUCH broader range of effort vs. the running that I was doing. Biking has all these surges, hills are often an important element of the race, etc

3) If you have the time you can do a larger volume of work on a bike vs. running (before over-training issues bring you down)

4) I did a couple times per week doing heavy leg presses on an incline board. I think that was very helpful in biking - I can't know for sure but I don't think it would have been as helpful in running

I would guess that you would benefit from extending your long ride (to say 3 hours) if that is possible - even if only occasionally. I was always at my best in long steady efforts but it sounds like VO2 max kind of stuff is more your thing. So biking is probably a good fit for you. Good luck.

dave