Originally Posted by
el forestero
I frequently climb long, steep hills and am trying to decide whether it's worth buying an 11-34T cassette for a bike that has an 11-30T cassette and a 34T small chainring. When riding up continuous grades of 10% to 20% for 40 to 120 minutes at a time, how noticeable would the difference be between running on 30T and 34T cassette cogs? Is each pedal stroke likely to feel significantly easier on 34T or does this feel like a subtle change?
What chainring are you using? Of course everyone has different needs and fitness, but I ride in the same areas as you and find that a 50/34 chainring combined with an 11-30 cassette is sufficient for me.
I intentionally replaced my Domane's 11-34 cassette with an 11-30 cassette because, combined with the 50/34 compact chainring, not having the 34T cog on the 11-30 cassette bothered me less than the big jumps between the higher gears on the 11-34 cassettte (
11-13-15-17-19-21-23-25-27-30-34T vs
11-12-13-14-15-17-19-21-24-27-30T). I have a very low mileage (about 200km max.) CS-HG700-11 105 series 11-34 cassette for cheap if you're interested.
FYI if you do swap out your cassette make sure your RD can handle the 34T cog first. You'll also likely need a longer chain.
Edit: just saw from your profile that you lead bike tours in Japan so I'm guessing you know a thing or two about bike maintenance and repairs. I'm kinda surprised you're asking the question in the first place tbh. Dude, just try it already, and claim the parts as a business expense
