Cassette Ratios

[Roons]

I need some help in cassette ratio's.

 

 

 

I recently purchased two 11-32 cassettes - my bike is currently fitted with an 11-34.

 

 

 

How big will the difference be, especially on hill climbs ? Is it worth worrying about?

 

 

 

Cheers

 

 

 

 

[Fulmenicilus]

No need to worry! If you need a 34-granny combination you're probably better of pushing anyway. A further plus is the fact that the jump between gears are less noticable with the 11-32!

[BigGuy]

Nothing to worry about. You can climb stairs with a granny and a 32.

I made myself a little spreadsheet to see exactly what combination of crank/cassette gives what speed at what cadence.

 

Cassette tooth count:

	aq	as
28	32	34
25	28	30
22	24	26
20	21	23
18	18	20
16	16	17
14	14	15
12	12	13
11	11	11

 

Typical crank combinations:

 

48	44
36	32
26	22

 

The gear ratio is simply the crank teeth count divided by the cassette gear teeth count.

 

To work out the typical speed at a given cadence:

 

cadence x wheel circ (i use 2.068m) x gear ratio x 60 / 1000

BigGuy2009-01-07 07:54:30

[Daxiet]

11-34 is good for starting out or perhaps mixing with the Double Chain ring option some MTB'ers are going for.

 

If however you have a decent level of cycle fitness the 11-32 is the right cassette to have, the 34 tooth granny gear selection is not worth the speed you'll get, as Fulmenicius said you can push faster.

 

I must say when starting out I pondered switching over to the 11-34 tooth option on almost every super steep climb. Now I like my 32 tooth and tend to use it and the small chainring very infrequently.

 

[TNT1]

Sorry, what? Who's climbing a granny?

[Daxiet]

It was me!