12---25 & 11---28

Carpenter

If I change my 12/25 to 11/28 will I notice much of a difference or am I just kidding myself thinking I will go faster up and down hill,s.

What say you

ROK ON

You will go faster uphill if your cadence increases by more than the gear inches declines.

You will go faster down hill if your cadence declines by less than the gear inches increases.

smacl

You may also find uphills a good bit easier, as you can go slower at a higher cadence.

karlmyson

I made that change about 18 months ago and it made a positive difference to me on most hills. There's a cadence/power relationship, and having a better ability to spin on a steep pitch gives you a better chance of getting more power (and speed) out.

Some people are concerned about a more 'gappy' cassette, but I haven't found that a problem. Plus - you have an 11 for powerful descents!

kincsem

^what he said.

Have you ever been in bottom gear on your bike? If yes, then a lower gear might be useful. I've never heard of anyone not using their bottom gear, yet you will hear people insist they don't need low gears.

Dubba

I've a compact and recently changed back from an 11-28 to a 11-26 and find it much better. I have to say im one of those who noticed a big jump in some gears. Maybe its not so evident with a standard?

Morrisseeee

I've a compact & I use an 11-26 for climbing/exploring, and I use an 11-21 for racing/flatish routes. The 11-21 is an interesting one as it gives you 2 extra options: the 14 & 16.

Edit: OP, do you mean going from a standard with 12-25 to a compact with 11-28 ?
If so, then you will see differences, as in different gears & cadences.

Inquitus

karlmyson wrote: »

There's a cadence/power relationship, and having a better ability to spin on a steep pitch gives you a better chance of getting more power (and speed) out.

I'd defo agree with this. There's a point at which your performance starts to fall off badly as your cadence drops too low in the granny ring when the road ticks up too steep.

cdaly_

I use a 13-25 on a 52-42-30 triple. Don't need the 11 or 12 since I worked on better cadence but I'm not sure I'll cope without the 28 from my last cassette.

cranks

this might help you

AstraMonti

http://gear-calculator.com

An awesome calculator might help clear things up. Like the above, but more easy to grasp.