What is this effect on my chain called? I have a new road bike and when I move into the largest cog in the back, some variation on the above photo happens every couple of rotations. (Has been fixed by adjusting the barrel adjuster). I'm curious: what is this called?
The photo shows the result of a derailleur being out of adjustment. There are many on line tutorials that explain derailleur adjustment. There is also the chance that the trainer stand is somehow interfering with the derailleur movement.