In my design, http://www.bikecad.ca/1459607072404, if I select one of these drivetrain gear combos:
Chainring 1, Cog 7
Chainring 2, Cog 2
Chainring 2, Cog 8
...my chain snaps! Seemingly only in these gears with no extra links. If I put in an extra link, different gear combos snap the chain. Easiest to see if you choose not to display the crank. Wierd. Can anyone suggest why this might be?
Thank you very much for free bikeCAD, I love it.