There are a few parts glued to the background. Really hard to find out which ones. It happens sometimes if you use the brush tool. To avoid this problem use "glue together" rather than fixates and check whether parts stick together or are glued to the background immidiately. I remeber working on my ragdoll over one hour just to find out that one single limiter was glued to the background and the upper body.
TimTheOne took the time to fix it. Here's the scene.

http://www.algodoo.com/algobox/details.php?id=38941

The only problem is that he used Algoodo to do it so you will have the bouncing water problem after loading the scene.
To fix this save the new scene, close Phun, delete the original fixed scene and delete your config file in your Phun folder. When you start Phun again you will have a working Phun as well as a working bike.