IK constraint following object goes haywire So I have an armature sitting on a bicycle and have created IK constraints on the feet/legs to follow the pedals of the bike (So the pedal is the target)

The issue I'm seeing is that in object mode when I preview the animation of the pedal turning the simulation looks amazing. The second I click away, back into pose or to timeline it gets all jumbled. I'm missing something here. Any ideas?

Here is a link to a screen capture of the issue.
https://youtu.be/0a1_SQGDnW8
Go into the armature in edit mode and bend the knees in the direction they are supposed to bend just a tiny bit.

If the legs are completely straight, the ik constraint might get confused which way to bend the knees. 

Or give the IK constraint a pole target.
I made a video on this here:
https://vimeo.com/171279647

If you upload your .blend I can make a .gif on your specific example.
https://blend-exchange.giantcowfilms.com/