I have an Ultegra triple with 52/39/30 and would like to go to 50/39/30. Is this a big deal (need to adjust front shifters, rear etc.) or simply a matter of changing out the rings?

Thanks!

Simply a matter of changing the rings.

you should also lower the front dérailleur since having it set too high results in poor shifting performance.

^^ then you'll have to adjust the front der. still not a big deal, though

Try it. It might work fine with no other changes. Lowering your FD might cause pickup problems with the middle ring. The difference between 50 and 52 is pretty small.

I also have to wonder why you would bother to do this, especially if you aren't using a smaller inner chainring, like a 26 or even a 24. What do you gain?

Why not swap the 39 for a 42, and use the middle ring more?

Middle ring has the best chainline too (or should).

>Why not swap the 39 for a 42, and use the middle ring more?<

Why would swapping out the 39 for a 42 give more use of the middle ring? Wouldn't the fitness - or lack of fitness - have more to do with the number of appropriate teeth on a ring?

Because the bigger middle ring will give you higher gearing per whatever cog you're in and you won't as often have to upshift, e.g. if you just want a quick sprint or are going down a short downhill section, you might not want to change rings. That 39/12 is just not high enough whereas the 42/12 might be.

I actually do have a triple with 42/52 rings and I like the 42 a lot for a quick sprint when I just don't want to change rings. I seldom if ever use my big ring. A 42 tooth ring is what you'll often see on 1x9 set-ups for just that reason.

>That 39/12 is just not high enough whereas the 42/12 might be.<

I understand. However, some riders, depending on strength/age, etc., might be better able to make use of the 39, which I'm guessing is a lot of people. Otherwise many bikes wouldn't come equipped that way. In my case, I like riding hills, and I find I use the bottom end of my 39 a lot, even on steep grades - the 42 wouldn't help me much.

Thanks for the responses.

My reasoning is that I rarely get onto the 52. But I spin out of the 39 too easily. When I do go to the 52, the double shift to a larger rear cog is pretty large.

Truth be told, I would rather go to a compact, but that requires all sorts of changes and expense. The idea of switching to a 42 middle ring is interesting. I would then need to go to my small ring more on the hills and wouldn't that also increase the cross-chaining?

My rides are hilly, but not mountainous. So, the choice is, would I rather spend more time in my middle ring, with slightly more time on the small ring or more time on the big ring and almost no time on the smallest ring?

What do you guys think?

The difference between a 50 and a 52 is not actually that big if you run the gear calculations. What kind of cassette are you working with, and would another cassette give you a better range of options, potentially?

Cassette is 10 speed 12-27.

If you look at a gear chart, with a 50t and a 39t, you go up from about an 88 gear inch on the 39t, to 90.0 on the 50t. You get an additional three gears, approx. 96, 104 and 113.

With your current 52, you make exactly the same jump, from the 12t to the 15t, this time from about 88 to about 94. You again get an additional three gears, approx. 100, 108 and 117.

So you'd have to make the same amount of jump when going from 39t to 50t as you do now w/ 52t. What you really get out of the smaller chainring is a closer jump, from 88 to 90, instead of your current 88 to 94.

Going with a 42 might make more sense because you would pick up an extra high gear in your middle ring, which is what your looking for, and you wouldn't lose anything off the low end (it would be there w/ the 30t).

My bike came with a 52/42/30 and I changed the rings to a 50/39/30. Just lower the front derailer slightly and it works fine.

Thanks toall! Have to chew on this a while...

My final thought - leave your gearing alone. All the gears you want are there. You have to make a jump to the larger chainring at some point, anyway, once you get up to speed. You're not going to gain or lose anything by changing either the outer or middle chainring. OK, you could lose a few grams by dropping two teeth with a 50T chainring - that's all.