Originally Posted by
HTupolev
The main benefit of having closely-spaced ratios is that you have closely-spaced ratios.
Power is, more or less, your pedaling torque multiplied by your cadence. Shifting allows you to balance how much torque your legs are having to put out versus how fast you're having to spin your legs in circles. Having more closely-spaced ratios means that you have finer control over this.
Wider ratios primarily make for a more disruptive shift, i.e. they'll create a larger change in the pedaling force you're having to push with, and the rate at which your legs are spinning.
Got it! Makes total sense. Thanks a lot for helping me understand that.
Originally Posted by
HTupolev
This really depends on the particulars, because it depends on the terrain and the rider and the riding, and variation in all these things is huge. What's the context? Do you have a bicycle and you have some issue with it? Are you contemplating a bicycle purchase, and you're wondering what to look for? How strong of a rider are you, and what sorts of rides are you doing? What parts of your gearing range are you spending a lot of time in?
Yea', I have a bike and was upgrading to Di2 Ultegra. My previous groupset always had issues with the shifting and was actually defective right out of the box.
I honestly don't know how to describe my riding style. I wouldn't say that I'm a "strong" rider. I like longer rides. 6+ hours. I'm never really riding at a consistently fast pace. I don't ride in groups. The majority of my rides are usually pretty casual (I'm averaging about 17 mph), though I do speed about 20-30% of the time? And during those times, I'd like to experience shifts that are not disruptive - at least less so than other cassette's.
I'm mainly in the top sprocket of a 50/34 chain wheel, but with regard to the cassette, though I honestly never paid super close attention to any of this, I believe I lingered in the 14 to 25 range most of the time and, as mentioned, took advantage of the 32 cog from time to time. I just don't know how big a difference there would be on a 20% incline between the 32 and, say, a 28 or a 30T cassette and whether or not that difference is worth it to me.
Originally Posted by
WhyFi
HTupolev explains it really well, but I'll elaborate a little based on my experience.
Personally, I didn't really care too much about close ratios until I started training and riding in fast-paced group rides. In situations where you're at the very limit of your capabilities, hanging on by your fingernails, I find that having closer ratios helps a lot to keep you in a pocket of cadence *and* torque that's manageable. It really sucks to be just hanging on and then find that you're straddling a gap where the cadence is a little too high with one cog and the torque a little too high with the other. This is, obviously, just my experience and can't speak to the sensitivity of others with regard to this.
Thanks for elaborating. It does help me see things much clearer now.
Originally Posted by
WhyFi
That said, I can usually power my way up and over the vast majority of them within a handful of minutes.
I may be wrong and might even wind up regretting my choice, but I just feel like this more than likely will be the case for me. I don't have many climbs and the one's I have aren't that steep.
Originally Posted by
WhyFi
Because of my terrain and riding habits, both with solo and with the group, I prefer tightly spaced cogs and have been riding with a 50/34 and 12-25t for the last few years.
I'm starting to lean more towards a 28 myself right now, but still on the fence. Will have to think about this some more.
Originally Posted by
DaveSSS
Percentage difference between the sprockets is what matters. Shimano has a horrible 11-34 with large 11-13-15 jumps from the start, where it should be 11-12-13-14. Campy does it right, with as many small changes as possible, and larger changes only in the largest 3-4 sprockets.
My sram axs 10-36 cassette is OK, but not perfect. It doesn't have a 14. It should be like Campy's 9-36 13 speed, without the 9. 10-11-12-13-14-16-18-20-23-27-31-36.
Okay, I get it now. Thanks! So the gaps in between an 11/30 are slightly shorter than the 32.
28: 11, 12, 13, 14, 15,
17, (1)
19, (1)
21, (1)
23, (1)
25, (2)
28
30: 11, 12, 13, 14, 15,
17, (1)
19, (1)
21, (2)
24, (2)
27, (2)
30
32: 11, 12, 13, 14,
16, (1)
18, (1)
20, (1)
22, (2)
25, (2)
28, (3)
32
I guess there might be a slightly less noticeable (slightly less disruptive) shift with the 30T than there would be with the 32 (and maybe even ore so with the 28 vs the 32), since there's up to three spaces on the 32 (in between 28 to 32) and from one to two with the 30. And with the 28 there's only one space starting from 15 to 25 and then finally two spaces that happens once right at the very end, where it jumps twice from 25 to 28.
I guess this is all boils down to preference and what I'm willing to sacrifice for the sake of potential gain in smoother (or less disruptive) shifting. Might just have to test ride a 28 when I get a chance. Probably not too many hills around my LBS's, but it's the only thing I can think of that might giving me a better, experiential understanding of the differences.