Thanks. My point is that in windy, flat Houston I mostly haul my ancient ass around with a 2.3 front to back ratio +/- 1 cog and could get that with the 53/23 as well as the 39/17 on my 11-26 10 speed cassette. I do tend to spin pretty high cadences of 90-100 almost all the time. (Let's just ignore for the moment that I might be tempted to use the 53/26 extreme cross chain combo in a headwind.) I should get at least double cassette life if I split my time between the two front rings. I was just wondering if the chain life would also be extended due to the cassette staying in better shape for a longer time. Makes no difference really. You have to replace the chain when you have to replace the chain. It was just an idea that interested me.