I'm a road and mtb regional racer about to have a go at my first road endurance nationals very soon.
I'd like some educated scientifically validated answer on a matter that has been on my mind ever since I got a new bargain race bike that unfortunately came with a compact crankset. I actually went from 39/53 + 12/28 10speed to 34/50 + 11/28 11speed.
On paper I'm a lot better off with the new setup, since I'm using the exact same spacing on the cassette with the benefit of the 11t cog i didn't have, which, even though doubled with a compact gearing upfront, ends up giving me a lot more headroom in bottom and even a tad bit more top speed.
My coach has always insisted that even on same gearing ratios, when compared, a larger crank ring with a smaller cassette cog end up giving you higher leverage and ultimately better power transfer or whatever mechanical benefit. Last Saturday, trying out hard climbs on fresh legs with about same gear ratios on the 50 vs my 34, actually felt less efficient on the 34 for some reason, mind you same cadence, intensity, gradient.
What's your take on all this? If the math says gear ratios are same, are the actual ring and cog sizes irrelevant? Is it actually beneficial to switch to my standard crank due to increased leverage?
Thanks a lot, lads!