Originally Posted by RChung

A friend did a little test a few years ago. He mounted a SRM and a PT
New here... what is SRM and PT


I've indicated the rings and cogs used for each section in the top panel. You can see that 54x16 is bracketed by 42x12 and 42x13. The middle panel shows his power output -- steady at first, then a ramp up for each gear combination. The bottom panel shows the difference between the SRM and PT power. What you can see is that more power gets through to the PT with the larger chainring, i.e., fewer losses.