I am new to the sport, and have just started to introduce cycle-run sessions to my training.
The problem is every time i attempt a session, after 2-5 mins of running i am getting severe stabbing pains in my calves and have to stop, resulting in no running at all for anything up to 2 weeks.
I never get this problem during run only sessions.
Try stretching in between the two. HOw long have you been training at the two different disciplines? You might also want to lower your milage on the bike a bit at first. I don't know how far you are riding/running at the moment.
syd