Posted by: RAHrider
I can run 2-3 chains on the all steel cassette. I don't really use the 10 tooth cog very often, so running a 28t chainring is not the biggest deal. For a 220lb rider, I think it's the least expensive option for me. I try to change the chains at 0.5 to try to maximize the number of chains I can wear on a cassette.
That's what I am thinking too. I got the all-steel Deore 10-51 cassette so I could use the 45t and have better chainline and run a few chains without going through many cassettes.
Using a 30t it should be good but I also thought about going to a 28t to stay lower/more centered on the cassette too. More BB clearance too, and I think I never used the 11t on my previous setup.
If it was not for the shifting under load curiosity I would have stayed with 11 speed cassettes too, but since I have both shifters and cassette bodies, that will still be an option if it's not worth it. The added unsprung weight of the 12 speed cassette was something that was making me hesitate, but I figured that the under-load shifting was worth trying.
Another interesting thing regarding unsprung weight : Neko Mullally tested his bike with a 500ml bottle full of water attached to his left seatstay. After trying it at different spots on his bike, he thought he would feel the added weight on the seatstays the most, but he said that it was where the weight was the least felt, didn't impact his suspension's action much and if I remember correctly, the times were not slower either. I doubt I'll feel the added grams then!