SethAZ 

Thanks for your reply! I realize my own riding conditions aren't universal to everyone, so it helps to get other perspectives. If you don't mind me asking, what cassettes are you using with your 52/36 on the Tarmac? And at what cadence do you spin out? For me, the absolute spin-out cadence is around 105ish. My "threshold cruise" effort range typically has me spinning 92-95 or so, and for a slower cruise it'll often be high 80s - low 90s, depending on how much resistance there is. On group rides where folks were racing down a descent on my old bike, with a 50/13t combo, I spun out at around the 32mph or so range, give or take. Once I hit that speed it was time to just assume the most aggressive tuck I could manage and enjoy the ride.

You must be either really going fast, or have a much lower spin-out cadence, if a 52t large ring and either 11t or 12t rear cog still isn't fast enough to give you the resistance you want on your descents. On the other hand, since my riding is mostly flat I put probably much greater weight on fine gear shifting to keep my cadence as close to constant as I can. Given this sort of flat cruise style of riding, I really despise 2-tooth rear cog changes between gears while riding the flats, and even though I'm a fairly liberal guy, I hate that my chainline is left-of-center nearly all of the time. I imagine given the constant up-and-down nature of your riding, you probably put far less emphasis on the granularity of your shifts, particularly so if you're riding your 7-speed. :-) This gives me a lot to think about.

One way to look at it if I'm trying to figure out why manufacturers market the way they do is that a drivetrain like 50/34 with 11-34t cassette gives an enormous gear ratio range which covers just about anybody's needs, but at the cost of making the drivetrain suboptimal for just about everyone as well. I guess, considering that what's optimal for each rider isn't the same as it might be for the next rider, this is the best they can do. If that's the answer then I'd really be happier if they could make it cheaper for people to optimize their drivetrains for their needs. I'm a little torqued (around 4 Nm) that the price of replacement large rings is as high as it is. Most places advertise this 46t Ultegra 8000 large ring for like $160, which is 3/4 the cost of buying a whole brand-new crankset of the same model. That's outrageous. I found a bargain on this 46t ring at only $106, which is still fully half the price of a new crankset.