Phideaux wrote:

"I'm running 52/19..."

Fifty-two X 19 comes very close to my present set-up of 47X17, which comes out to about 72 gear inches.

Fifty-two X 18 will give me about 76 gear inches; perhaps too much.

If I decide to go back to 72 gear inches, I might try it with 52X19: I have this intuition that bigger gears have more mechanical efficiency than small gears of the same ratio.

I've come to think of 72" as the best compromise for both uphill and downhill.

I should probably order a Soma 19t cog and have it ready.