Originally Posted by
jimmuller
What in some circles is referred to as chain suck. With just the right combination of tooth spacing, chain ring separation, chain flexion, and stretching the chain gets stuck on a tooth on both chain rings. If you do it with enough force on the pedals it can get suck pretty hard.
The unfortunate consequences include dragging the chain against the chainstay and if you were pedaling hard enough pulling the RD forward hard enough to break it. That happened to me on a commute one rainy night about 1/10th of the way home. In the blink fo an eye the rear wheel locked and spun out and I hit the ground hard. Fortunately only the RD and my headlight mounted on the left side of the handlebar came away hurt too badly to be fixed. I had to rebuild the wheel but that was easy.
Aye. I'm used to an instance of chain suck on the Surly Trucker DeLuxe, in which the chain gets lodged between the small cog and the chainstay. This thing with the Rawland was more exotic, involving as it did the FD cage and an origami fold of several inches of the chain on two chainrings of the crank. In either case, the pedals lock, but free wheeling continues, so no crashing so far. Calling the dance of chain links and gear teeth with derailleurs and shifters perhaps deserves its own muse.
rod