Cassette Options

Rapier503

Hi,
Which is the best option of a cassette for hill work and which is a good all rounder and what are the others good for. I suppose I an really asking what is the difference between them all?
Cassette options:-
11-25
12-25
12-27
11-28
12-30

Thanks in advance.

ElectronShepherd

Hang on, I'll measure this piece of string...

Right, got an answer for you:

It depends.



More precisely, it depends on

1) Your definition of "hill work" (e.g someone in East Anglia vs. someone in the Pennines)
2) How strong your legs are
3) The size of the chainring(s) on the crank


If you're thinking of buying a new cassette, for any useful advice you'd need to say what problems you're having that makes you think a change is needed. At the moment, you're asking an unanswerable question (assuming you were looking for more than "they have different numbers of teeth on the cogs").

rolf_f

The above. However, as a fairly sweeping generalisation, you can probably reasonably say:

12-25: OK for a bit hilly but for a properly hilly ride, hard work.
12-27: Good for hilly but you'll probably wish you had a few more teeth on the big one if you have lots of really steep climbs.
12-30: Should be good for the most horrible routes you are likely to find! But on less severe rides, you'll not be using the lowest gears and maybe regretting carrying so many teeth at the back.

ie if you have to stick with one cassette and proper hills need to be got up using it, you can't go far wrong with a 12-27.

Ignore the 11s unless you have small chainrings.

florerider

^^ this

changed from 11-25 to 12-27. Not missed the 11, like having the 27. The ratios on a 12 27 are pretty good too, no big gaps.

I would question if you need more than 25 on the back what use an 11 would be.

ElectronShepherd

florerider wrote:

I would question if you need more than 25 on the back what use an 11 would be.

Don't see why you would question it.

If you need to go up steep hills and also want to go at high speed when you can, as wide a range as possible is a good idea.

dj58

OP, there is also the CS-4600 12-28T 10sp, doesn't have the 16T like the 105 12-27T, but a bit closer at the low end 21, 23, 25, 28 as opposed to 21, 24, 27, 30 for the 12-30T.

ai_1

ElectronShepherd wrote:

florerider wrote:

I would question if you need more than 25 on the back what use an 11 would be.

Don't see why you would question it.

If you need to go up steep hills and also want to go at high speed when you can, as wide a range as possible is a good idea.

Likewise. I've seen this comment made before and it makes no sense to me. The implication seems to be that if you want more than 25 teeth at the back you won't be able to turn over a 50/11 combo. I have to assume these people never ride proper hills or mountains? I'm currently using a compact with an 11-28 on my road bike. In the mountains I'm often glad of the 28 on ascents but I also get plenty use out of the 11. Having said that, I'd sooner give up the 11 for a 12 to reduce increments between gears than give up the 28 for something smaller.

rolf_f

Yes, if you go up a steep hill, you might expect to go down one as well! For the alps I made up an 11-29 out of an 11-25 and a 13-29. With not much flat to worry about, big gaps in the middle weren't a problem.

But that said, the 11 really wasn't that useful. The climbs were I was were pretty steep so you either got past the point at which you benefitted from the 11 quite quickly anyway or you were braking for a hairpin long before you got to that point. In practice, the 11-28 seems to be the ideal cassette for a very narrow set of route circumstances. With a 50 tooth chainring, the difference at speed between 11 and 12 is about 3.5 mph. Once you've accelerated past that additional 3.5 mph, you are relying on gravity whether you have 11 or 12. Obviously, on a certain gradient, you might be able to keep pedalling at max cadence for a long time - and that gradient is the one which makes the 11 work. But how often you find it is another thing. When I was in Samoens, I think the main time I benefitted from the 11 was descending the Columbiere into Cluses. Otherwise the gradients were too steep mostly.