Originally Posted by
icelemmings
This has probably been discussed to death: what is the benefit of riding either 32-12 or 40-15 (the GI are the same for both options). I'll take my road bike out tomorrow evening and compare two similar GI ratios, but for now, any quick answers?
I would guess - and just common sense speaking - that more teeth (40-15 over 32-12) distributes wear more, and so will last a bit longer.
Also common sense, the difference in lifespan will be pretty negligible.
Conversely, smaller cogs/chainrings will be a couple grams lighter. Kinda reaching there, but yeah.
I'm not sure if there are more inherent efficiency gains between the two.