I went with a 11x25 rear cassette and am now thinking that was a bad move.

I live in Indiana where it is mostly flat with a few rolling hills. Would a 11x23 have been a better call? Or is it splitting hairs to change from what I have?

I don't see how the extra two teeth are hurting you in any way. With either cassette, you have the same size strong gear (11 teeth). Why would you want to switch?

I live in Illinois and have an 11 23. The bike came with a 12 25, I am glad I made the switch. You did not say your what crank you have but I have a compact. I think the 11 23 give nice close gears for the terrain. If you have some longer hills and in southern Indiana them maybe you are fine. Otherwise I would change. I did a century yesterday and never went in the small ring and never used even the 23 ring, it was all 21 11.

You're fine. You may find some climbs out there somewhere.

11-21, if the 21 is enough to get you over the rollers.

I'm glad i don't live in indiana.

^^ lol

How many Watts under the hood? If you don't find yourself using the 25, then go with a 23 or 21.

Is there too much gap for you between a pair of gears? Do you ever find yourself pedaling at a high cadence, shift, and then find yourself mashing? Unless you find yourself jumping over that "just right" point pretty often, there's no reason to change.

You lose the 16T gear with the 11-25. What that means to you depends on your fitness level, crank type (double, compact double, triple) and riding style.

I've got a standard double and an 11-26, works out great for me in west central Indiana. It allows me to pretty much always be in the big ring unless I'm warming up or riding around brown county. I never use the 53x26 combo to avoid cross chaining so the lowest I normally will find myself wanting is the 53x25. Works out well in most situations.

Ride what you got. Then see what's missing. Do you want a bit lower gear, or better spacing?

Also, the 11-25 is going to let you stay on the amall ring more without cross chaining, which can matter depening on your cruise speed

depends.

If you can't figure this out for yourself, as in riding your bike & making the necessary call on your personal gearing requirements..

never mind.

Good point. I love the 16.

Me too, but I need to do more hill work before I can go back to the 23.

If you have a compact crank and are like most riders, the 11/25 is more likely the ticket since you'll spend less time in the situation where you're too close to the bottom of your big ring or too close to the top of the small. Even if you have a standard double, you might consider the wider cassette simply because you'll want those extra teeth if you're in a sufficiently strong headwind.

Get what you like.

I have a standard 39/53, live in mildly hilly chester county, and LOVE my 12-23. I don't need the 53x11, and like the close spacing of this cassette.

On the other hand, I am a cheapskate so I would keep the current cassette until it is worn and tweak the gearing when getting the replacement.

Erm......

10sp 11-23 = 11, 12, 13, 14, 15, 16, 17, 19, 21, 23 teeth
10sp 11-25 = 11, 12, 13, 14, 15, 17, 19, 21, 23, 25 teeth

Yeah, that's splitting hairs.

I have a standard 53/39

I do find on the flats it tends to feel pretty tight on the higher gears.....

I avg 200 watts on a 25 mile group ride

i have 12-25 and it is fine for rolling hills here. the hills are never long enough to need more. i wouldn't like to be without the 25 though.

I have always liked a 12- 25 for most anything.

How often do you use the 16T gear with either ring? That is the question. It's only splitting hairs if you won't miss it.

^^ 16 is a pretty sweet gear.

On my old-school 6 speed I have a 13-21 (13-14-15-17-19-21) and I really really miss the 16.

Do you really use a 53/11 on the flats? I'd use a 12-23. I rode the rolling terrain around Kansas City for 20 years and rarely used anything larger than a 21 until 10 speed came out. Then a 12-23 would be perfect.