I've heard of a 52/34 working fine. Is there any reason a 33t chainring on a compact wouldn't work as well? Has anybody here done so?

I did over 6,000 feet of climbing today, with almost 2,000 of it in a 5 mile stretch, and every extra bit would have helped. I don't want to have to go to an 11-36 with a new RD if I don't have to though.

I think the smallest chainring that will fit on a compact crankset is a 34.

I've read about a 33 tooth chainring, it's out there somewhere. My guess is adjusting the FD so it'd work would be the hard part...but people use standard FDs with a listed 15 tooth max spread with compacts all the time, so it probably works. I'm not sure going through the hassle and expense would be worth it for one tooth, but that's just me.

A 33t is the smallest that will fit on 110 BCD cranks. But some cranks' arms are long enough that the chain sideplates will hit the crank. You won't want to use the 33t on those cranks. The only way to find out is to try it. From my experience its more likely to be a problem with carbon crank spiders than with aluminum ones. I bought a 33t ring for a climbing race and discovered that my crank was one of the ones that it won't work on, so I have not tried the shifting. It'll be worse than with a 34t but I don't know how much worse.

You can get 33t rings from Harris Cyclery.

You might consider a 11-32 or 12-32 Sram ten speed cassette. These will work with many, but not all, road derailleurs.

See: https://www.bikeforums.net/showthread...r-fear-no-hill

If you have a nine speed cassette, try the Harris "century" cassette: https://harriscyclery.net/itemdetails.cfm?ID=2369 or https://harriscyclery.net/itemdetails.cfm?ID=702

climb in the 50

I'm already running a 50/34 with an 11-32. I made it through the sustained 12-17% section, but my heart rate was at 90-92% (~185) the whole time, and my cadence was around 50. Doable, but not ideal.

I ride in the Rockies, but even climbs like that are rare, so I'll probably just hammer it out until my respiratory system and muscles catch up. Even then, the 33T would almost make up the 1 tooth difference, allowing me to run a 12-27 instead of a 12-28 on my normal wheels. I really appreciate those smaller gaps in the cassette, and don't mind the bigger gap between the chainrings.