When I started playing with gearing a while back, I just decided to go with entire crankset changes and sell the leftovers on Ebay. The only reason I'm now mixed on the Tarmac is because it came with longer cranks than I wanted and I was in a hurry to ride it. The 50/34 was intended to go on my Raleigh to have a bike more suited to some of the steeper climb routes I do. Wanting to keep the 52/36 on the Tarmac I just had them swap cranks when they built it.

Shimano has drifted pretty far into the proprietary CW direction first with molded 5 screw CW and now with molded
4 screw CW. Replacement CW are costly enough that it makes sense just to buy a new crankset instead.
My own direction has been from triple 52/42/30 in which I spent 80% of my time in the 42t CW 15% in the 52 and
5% or less in the 30t. The change to 50/39/30 was nice and I spent most of my time in the 50t.
Di2 made the 50/34 practical and time forced changes from 11-28 cassettes to 11-32 and now one bike is
48/32 CW and 11-34 cassette which is sweet. Downhills are for coasting not Strava KOMs especially since a
flat induced crash at 35mph on a long downhill 15yrs ago. I am too fragile now for another one of those but
will still let the bike roll out to 40+ on a hill I am familiar with. The 50/34 CW will be replaced with a 46/30 when
the 50/34 finally wear out.

I've been horrible at selling things, but I need to start doing it. When I mounted the Stages L/R power meter I removed the original Ultegra 6800-generation crankset and set it aside, and it's still perfectly good with maybe 2500 miles on it.

One of the unfortunate side effects of going with a crank-based power meter is I'm forced into buying new rings if I want to replace or upgrade them. Oh well. I wanted the power meter more than I wanted the ability to swap whole cranks. But yeah, paying like $150-170 for a chainring when a full crankset is only a little over $200 is ridonkulous in the extreme.

Harding -- now there's a marque I haven't seen since the 1960s and 1970s, when I lived in west Los Angeles and frequented Charlie Harding's shop on Westwood Bl., just south of UCLA. He had a full board of individual Regina cogs to support my "gear fiddling" habit.

I thought I'd post an update, as I've got over 200 miles and a handful of rides in with the 46t chainring now.

I'm really, really liking it. I'm digging having that one more lower gear before I would have to shift the front derailleur. In fact, on my flat-road rides now I don't need to shift the front derailleur at all anymore, because I can start off from a stop in my 2nd-to-lowest cog in the big ring and be just fine.

The deepening of the speed range where all my shifts are 1-tooth shifts is nice. At cruising speed the shifts were mostly 1-tooth shifts anyway, but this change got me to the 1-tooth shift territory one gear lower, so sooner into my acceleration up to cruising speed.

I did have one incident where I nearly paid the price for giving up the top 50/12 gearing for a top 46/12 ratio. I did an extended ride that took me up to some gradual climbing leading up to a pass through some hills with a decent downhill stretch. This young, thin guy on a mountain bike passed me as I was turning right onto that street. Since I weigh a lot and we were climbing gradually I had to increase to my threshold power to keep the distance between us constant and begin to slowly overtake him. I could tell that really wanted to stay ahead of me because as I began to close the distance he stood up and pedalled like mad a couple of times to stay ahead of me. I imagine he was thinking "I'm gonna really show that fat old roadie what I can do on my mountain bike!" but I'm no mind-reader, so I can only interpret what he did. And what he did was try really hard to stay ahead of me.

I'd closed most of the distance as the grade dropped and we were heading into the shallow downhill portion. The grade was low enough that gravity alone wasn't going to do it, but high enough that with a healthy above-threshold power output I was able to max out my speed. I'd finally reeled him in and passed him doing a little over 29 mph. I was already in my highest gear, and my cadence was climbing into the upper 90s. Probably 105-110 rpm is about as high as I could go. In other words: I was gear-ratio limited in how much faster I was going to be able to go in this apparent "young & thin 29er mountain bike vs. old and fat on a road bike" contest playing out. Probably fortunately for me, he was on a mountain bike, so he was gear-limited as well. My greater mass/surface area ratio and gravity were on my side, not to mention lower suspension and rolling resistance losses, and probably some aero advantages. He wasn't going to be able to stay ahead of me on his mountain bike.

If I only narrowly beat a young, thin mountain biker going down a moderate grade on the very occasional rides where any climbing is involved due to my choice to limit my high-end gear ratio in order to reap the benefits in nearly all of my rides, that's a price I'm willing to pay.

Anyhow, I'm very satisfied with the move to that 46t. The 46t is traditionally paired with a 36t, but I'm content for now to leave the 34t from my compact crankset on there. The front shifting has been just fine with it. If anything, I'd look to see if there was something lower for the small ring, like a 32 or even a 30.