The exercise bike is fine. DON'T use the eliptical trainer. I'm not a big fan of these as the motion of it causes you to lift your heel earlier than you would with normal walking (or running) which actually engages your calf muscle earlier and causes it to do more work! I have seen people actually cause themselves calf and achilles tendon injuries from using these machines.
The rowing machine may put a little too much stress on your calf too so maybe stick to the exercise bike for now.