A guy in my cycling club is selling a left-only stages power meter for a good price. It comes attached to an Ultegra 6800 left side crank arm. I have an ultegra 6700 compact crankset on my bike, though. Is it possible to replace just the left crank with Ultegra 6800 so that I could use this power meter without replacing the whole shebang? The cranks are the same length, but I don’t know what other compatibility issues I might run into. I can live with it being funny-looking, if that’s all it is.

Thanks!

Tom