25 to 27

[Peteaud]

Ive managed to get myself a Giant Defy 2 (2010) model for a very good price, however, its not 100% what i wanted (the price swung it) as it has a rear cassette of 25T.

Took it out for a ride today and struggled on the hill i get up on my hybrid.

After some net research i think i can swap the cassette for a 12-27t without changing the chain or rear mech.

How much difference will it make?

or do i change to a deore RD, 12-32t and a longer chain?

 

[ColinJ]

How much difference will it make?

or do i change to a deore RD, 12-32t and a longer chain?

It would only be a 7.5% lower bottom gear. If your current bottom gear is almost low enough, then it might be enough of a drop. If you need a big reduction though, then that 12-32 would be a better bet. That would give you a huge drop in bottom gear of about 22%.

 

[Peteaud]

It would only be a 7.5% lower bottom gear. If your current bottom gear is almost low enough, then it might be enough of a drop. If you need a big reduction though, then that 12-32 would be a better bet. That would give you a huge drop in bottom gear of about 22%.

I am thinking of finding a cheap used one on ebay and trying it.

Would 7.5% be very noticable?

I almost got up the hill that i can do on the hybrid, it was just a little bit too much for me.

12-32 is my probable route to give me the climbing i need long term.

 

[Nearly there]

My bike came equipped with a 12-26 cassette and Ive just bought a spare set of wheels and fitted a 12-27 cassette to them which I tried out yesterday,but couldnt decide if there was any benefit when climbing a regular hill over the 26 Maybe jumping from a 25 to 27 will.

 

[Rob500]

Hi Peteaud. You can check out the various options via http://www.gear-calculator.com/

Is it a triple Defy 2 or a compact? Either way you can check it on that page.

 

[Andrew_P]

I have ridden a SRAM 11-32 and it was very gappy big jumps.

I had a 105 short cage 11-28 on a model 5600 & 5700. which was ok, but since switched to a 25-11t

does the Giant have a compact double up front? You would have thoguht youwould need a longer chain for a 27 to 32?

 

[ColinJ]

I am thinking of finding a cheap used one on ebay and trying it.

Would 7.5% be very noticable?

I almost got up the hill that i can do on the hybrid, it was just a little bit too much for me.

12-32 is my probable route to give me the climbing i need long term.

7.5% would be a help, but not a big help! The trouble with the 12-32 is that the steps between the gears will be bigger and a lot of people don't like that. I think that is what I have on my MTB and the steps do feel a bit huge at the low end (between the bigger sprockets). Nice wide range of gears though ...

If you were that close to making it with a 25 then maybe a 27 and a bit of extra fitness is all that you need? (Mind you, there is always a steeper hill somewhere down the road, or you come to the hill when you are tired, or there is a strong headwind ... )

I used much higher gears when I was fitter than I do now, but I don't see any advantage in riding with gears that feel too high. They only put you off riding hills or you end up walking.

 

[Peteaud]

Its a compact with 50/34 up front.

Ive read that a deore rd (long cage) and a 12-32 will be ok, although a longer chain will be needed.

Might be a bit of a big jump tho, although my mtb has a 36 rear!

27 will fit straight on with no chain problems if i am reading everything right.

 

[Peteaud]

7.5% would be a help, but not a big help! The trouble with the 12-32 is that the steps between the gears will be bigger and a lot of people don't like that. I think that is what I have on my MTB and the steps do feel a bit huge at the low end (between the bigger sprockets). Nice wide range of gears though ...

If you were that close to making it with a 25 then maybe a 27 and a bit of extra fitness is all that you need? (Mind you, there is always a steeper hill somewhere down the road, or you come to the hill when you are tired, or there is a strong headwind ... )

I used much higher gears when I was fitter than I do now, but I don't see any advantage in riding with gears that feel too high. They only put you off riding hills or you end up walking.

Well i admit my hill climbing technique is crap at the best of times anyway

 

[ColinJ]

Well i admit my hill climbing technique is crap at the best of times anyway

Giving up smoking and getting your lungs working properly again must be helping! (Well done on that, BTW.)

 

[derrick]

I did the swop on my other halfs bike a short time ago because she was struggling with a couple of hills we do, but the last few rides we have done she has not needed the 27 tooth gear, i would persivere with what you got, you will get used to it, and the closer ratios do feel so much better.

 

[Banjo]

I changed an 11 25 cassette for an 11 28 on my Scott and it made a big difference on climbs.

I was replacing a worn chain at the same time anyway so dont know if I really needed to or not.

 

[beastie]

+1 for an 11-28. When I was heavier (2.5 stone) anything nearing a 10% gradient put me in the red very quickly. Changing from an 11-25 to an 11-28 meant I could manage steeper climbs straight away.

 

[Peteaud]

I changed an 11 25 cassette for an 11 28 on my Scott and it made a big difference on climbs.

I was replacing a worn chain at the same time anyway so dont know if I really needed to or not.

+1 for an 11-28. When I was heavier (2.5 stone) anything nearing a 10% gradient put me in the red very quickly. Changing from an 11-25 to an 11-28 meant I could manage steeper climbs straight away.

Would an 11-28 need a long cage rd or longer chain?

 

[beastie]

It works fine with a medium (gs) rd. I replaced the chain as it was worn anyway, it was 2 or 3 links longer, going by large-large and add a few.