Cassettes and gear choices

[jorgemartin]

When looking at a new 9 speed cassette, I'm confronted with different of gearing choices such as:

11-32
11-34
14-25

How do I know which one is right for me? And does this have an effect on derailleurs and cranks? Intended use is touring on expedition bicycle.

Thanks!

 

[HLaB]

What have you got at the moment ? its safest to start from there. If you are finding hills hard you might need a larger cassette but you might also need a larger derailleur cage. If you are feeling you gaps between your existing gears are too large go for a tighter spaced cassette (ie less range). If you feel you need the speed go for the smaller cassette. Or if you feel your existing cassette is fine go for that size.
Hope that helps :-)

 

[MacB]

for comparison purposes Sheldon Browns gear calculator is great:-

http://www.sheldonbrown.com/gears/

work out what your current setup is and then conciously think about what gears you use and which ones are rarely, or never, used. Then plug in some combinations you might be interested in and see what you like

 

[jorgemartin]

Is the gear calculator the only way to find out what the right set up is?

 

[Moodyman]

The gear inches measurement is the most common measurement for gear selection.

11-25 is a higher geared bike than 11-34.

The 11 is the smallest cog on the rear (highest gear) and the 25 is the biggest cog (lowest gear).

As other have said, see what you current have and then look at what you use from that to decide what you need to replace it with.

You find out what you have by counting the number of teeth on the smallest and biggest cog.


In my example, I had an 11-30 on my bike, but I never used the 30 (lowest gear). So when I replaced the cassette, I replaced it with 11-28.

 

[MacB]

Is the gear calculator the only way to find out what the right set up is?

nope, but it's the only way, on paper/screen, I know of to do comparative analysis, the alternative is trial and error which would be costly in time and money.

If you're just looking for a rough idea and a starting point then that's a bit different, and you need to be aware of what will work together:-

touring - having plenty of low gears is deemed useful, especially if you're heavily laden, most would say to do this via a triple chainset and, if need be, a wide range cassette.

if you want a wide range cassette then you would normally need a longer cage/MTB rear derailler to handle it. Shimano road stuff generally copes with up to a 28t largest cog on cassette. Whereas a MTB rear derailler will let you go to 34/36t, the downside to a wide cassette is that the steps between gears are larger. for example:-

a road triple of 52/42/30 and an 11-34 cassette will give you a high gear of 128(too high probably) inches and a low of 24 inches
a road triple of 52/42/24 and a 12-27 cassette gives a high of 117 and a low of 24 inches

the second option would give much more closely spaced gears, personally I'd go for a setup of:-

triple 48/38/24 and a 12-27 giving 118 to 24 inches, this also keeps the overall front spread at 24t and, as long as you can lower the front derailler to the 48t, from the 52t, height, will work nicely.


As you can see there're lots of ways to do this and people develop personal preferences over time, so you'll get many answers.

 

[adscrim]

Jorge

Only you will know what's right for you. What's you current set-up and how are you finding that? From there, you can use the gear calcualtor to compare what you have with your purchasing options.

I'm assuming that the set-up you have, when you say expedition cycle, is going to be MTB like. That being a small triple upfront and an MTB cassette on the rear. That being the case, the 11-32 or 11-34 would fit with the 11-34 offering an easier 1st gear than the 11-32.

 

[jorgemartin]

I've just found out that my set-up is 11-32. I don't think I ever use the 11. What would the difference be between 11-32 and 11-34? Is 34 more suitable for uphill? Is it noticeable?
Cheers

 

[PpPete]

For me - and this is only a personal opinion, NONE of the cassettes in the OP are right for an "expedition" bike.

11-28 might be OK with an MTB triple chainset (42-32-22) or something similar.
With a compact chainset or a "touring" triple like a 48-38-26, something like 13-32 cassette might be better - except they don't exist.

But... that's me, my legs, my preferred cadences, etc

As mentioned above.... work out what gears suit you, on the sort of terrain you intend to ride, with whatever load you intend to carry.

 

[PpPete]

I've just found out that my set-up is 11-32. I don't think I ever use the 11. What would the difference be between 11-32 and 11-34? Is 34 more suitable for uphill? Is it noticeable?
Cheers

34 tooth is going to be esier to push, and slower. With a small chain ring the difference is very roughly 10%, but with either you could find yourself going so slowly that you are at risk of toppling over sideways.

Another limiting factor - for me at least, is that, should I stop on a hill in the lowest gears I can't get going again, because there just isnt enough speed generated from the push with the lead foot, to get the other off the ground and onto its pedal.

 

[heretic]

If you're touring/camping in hill country go for the 11-34. Sooner or later the 34 will earn its keep. The west coast of Scotland or the Lake District is not the place to learn you're overgeared.

 

[Davidc]

I have a 22 cog at the front on the tourer and a 32 at the back. I don't use the 22 often, and the 22F + 32R is only for serious hills, but it gets me up almost anything here in the west whenI need it to. Up to about 10 years ago I wouldn't have considered a ratio this low, but age and health have necessitated changes! The chainset I'm using on that bike is 22 / 32 / 44.

I'm thinking about buying a Shimano Megarange, even though it costs a lot more than the trade generic cassettes I'd usually use, not only for its 34 ratio, but because it gives better spacing on
the higher 7 ratios for normal riding but with the option of the superlow gear when needed.

11-34 = 11 / 13 / 15 / 17 / 20 / 23 / 26 / 34 (megarange)
11-30 = 11 / 13 / 15 / 17 / 20 / 23 / 26 / 30 (HG30)
11-32 = 11 / 13 / 15 / 18 / 21 / 24 / 28 / 32(Standard trade cassette)

My resrvation is that on occasions when I accidentally change down a gear to far the 26 to 34 will be a bit much, and that the low gear could be a bit too low.

 

[Danny]

I posed a similar question a couple of years ago when I bought a new tourer.

I had always had rear cassettes with a wide range of gears but several posters advised me to go for one for a narrower range so that you don't have such big jumps between the gears.

I took their advice and bought the bike with a 12-27 cassette, and am glad I did. It definitely makes for easier gear changes, and provided you have a small front chain ring you can still cycle up most hills fully laden.

 

[Davidc]

I had always had rear cassettes with a wide range of gears but several posters advised me to go for one for a narrower range so that you don't have such big jumps between the gears.

Over the years I've had both, but I've always gone back to having a crawler gear available. For most riding though the closer spacing makes it easier to get muscles and road better matched though.

I took their advice and bought the bike with a 12-27 cassette, and am glad I did. It definitely makes for easier gear changes, and provided you have a small front chain ring you can still cycle up most hills fully laden.

It's the really steep ones that persuade me to stick with a very low ratio being available, and there are just too many of them in this area to ignore.

I used to just pile on the pressure to climb hills, but can't do it anymore so I do rely on having a low gear. Moving to the spread on the megarange might be better than the conventional cassette in that it would give a close(ish) 7 gear spread with the really low one there for the rare(ish) occasions when it's necessary.

I'll have to make up my mind when the present chain wears out, as the cassette is going to need replacing then.

I'm also thinking of changing from 22 - 32 - 44 at the front to 22 - 38 - 44. The main driver is that the middle chainring I have now is getting a bit worn while the 22 and 44 are as good as new, and I have a spare 38 of the same pattern, but the idea of having the closer spacing for the two which are most used with the small ring as a real crawling only granny gear has some appeal.