I currently am running a compact (110mm) 52/38 FSA chainring. I have a big ride coming up in June in the mountains 100 mile 13000 ft of climbing. I am wanting to put a 34t inner ring on and am wondering what exactly I need to do. Are all brands compatible as long as they are 110mm? I have found some on ebay for around $20 just wondering if it would work. I don't want to spend a lot on it because it will be used very little, just want to make sure it will work without problems.
Spec' Tarmac (road), Spec' Secteur Disc (commuter & tourer), Salsa Mamasita (MTB), CoMo Speedster (tandem), Surly Big Dummy (cargo), Airnimal (folder), a train pass, and NO car :)
There is no need to change the big ring if you're prepared to put up with the big change in cadence when shifting. The 52-34 jump should work OK, but not super smooth. If you can install a Third Eye Chain Watcher or K-Edge Chain Catcher to prevent the chain from derailling off the inside then that would be a good safety precaution.
To get as low as gear as possible for those 20% walls then you could even get a 33 tooth inner ring, TA Specialites makes one, but many companies have 34 as their smallest 110 BCD ring.
once you are in that small gear , you need to be at the crest of the hill
and coasting down the other side to do that upshift, and in that low ring
there is a likely hood of dragging the chain against the side of the big chainring