I'm new to cycling, having first started riding in April. I commute 16mi round trip 3-4 days a week and have gone on some long rides between 18-20 mi. I swim like I'm drowning so I don't have much of a desire for a Tri but I do run the Chicago Half Marathon every year (this will be my 3rd CHM, 4th overall) and I do the odd 5k and 10k road race. The commuting rides have basically replaced my in week training runs of 3-4 miles, to positive results so far. I still do the long training runs (11 mi next week) though, since I do have to actually run the race.
My question is: does anybody know of the cross-over effects of running and cycling from a training perspective? I'd like to keep up some of the running, but I seem to like cycling much more, and it is far less stressful on my knees (I'm a clyde, I know). I also would like to start doing much longer rides after 9/14 when the race is over with. Ideally I would through in some weight training, but I'm still trying to fit in 2-3 hour rides on my bike!