11-25 vs 12-25 or some other 11/12 ratio

richard36

Would appreciate some advice.

I bought my road bike 5 years ago. I can't remember why but at the time I was advised by the guy who did my bike fit to go with 11-25 on the back and 50/34 on the front.

I cycle about 120 miles a week on flat roads, undulating and hilly roads so a bit of everything (though the hills are not that steep).

I need to change the cassette. I normally buy from Wiggle and they have 11-23 and various 12 ratios - no 11-25.

Should I stick to 11-25 or would I benefit from some other ratio? (I have looked for the answer on the web but don't really understand the various explanations).

Thanks

mrb123

Richard36 wrote:

Would appreciate some advice.

I bought my road bike 5 years ago. I can't remember why but at the time I was advised by the guy who did my bike fit to go with 11-25 on the back and 50/34 on the front.

I cycle about 120 miles a week on flat roads, undulating and hilly roads so a bit of everything (though the hills are not that steep).

I need to change the cassette. I normally buy from Wiggle and they have 11-23 and various 12 ratios - no 11-25.

Should I stick to 11-25 or would I benefit from some other ratio? (I have looked for the answer on the web but don't really understand the various explanations).

Thanks

Do you find that sometimes you wish you had an easier gear? If so, get an 11-28.
Do you find that you never use your largest cog on your current cassette? If so, get an 11-23.
Do you think that your current spread of gears is just about perfect? If so, get another 11-25, or a 12-25 if you never use/need your 11 tooth cog at present.

richard36

Thanks

Only very occasionally could do with easier gear, and yes I suppose the gears are okay at the moment.

What would a 12- 25 cassette give me over a 11 - 25?

germcevoy

Richard36 wrote:

Thanks

Only very occasionally could do with easier gear, and yes I suppose the gears are okay at the moment.

What would a 12- 25 cassette give me over a 11 - 25?

A marginally lower gap between cogs making a negligible difference to mainting cadence. Otherwise you will spin out slightly sooner on downhills.

Harry182

Richard36 wrote:

What would a 12- 25 cassette give me over a 11 - 25?

-- specifically a 16t cassette cog. 50x16 is good for around 35kmph/22mph at 90rpm.

I use a 12-25 and will replace with like (or a 12-28). Ymmv -- I'm old, slow, can't be assed to pedal down hills and like the jump between gear ratios as small as practical.

svetty

I use the 16T much more often than I use an 11T. 12-25 is the better option IMO.....

richard36

I've gone for the 12-25

Thanks

Alex99

Harry182 wrote:

Richard36 wrote:

What would a 12- 25 cassette give me over a 11 - 25?

-- specifically a 16t cassette cog. 50x16 is good for around 35kmph/22mph at 90rpm.

I use a 12-25 and will replace with like (or a 12-28). Ymmv -- I'm old, slow, can't be assed to pedal down hills and like the jump between gear ratios as small as practical.

Yup. Some riders miss the 16 and find the 15 to 17 jump is noticeable.

philbar72

Alex99 wrote:

Harry182 wrote:

Richard36 wrote:

What would a 12- 25 cassette give me over a 11 - 25?

-- specifically a 16t cassette cog. 50x16 is good for around 35kmph/22mph at 90rpm.

I use a 12-25 and will replace with like (or a 12-28). Ymmv -- I'm old, slow, can't be assed to pedal down hills and like the jump between gear ratios as small as practical.

Yup. Some riders miss the 16 and find the 15 to 17 jump is noticeable.

definitely. 16t ftw.

drlodge

Go Campagnolo and 12-29 FTW!