Awesomeguy

I have a 2020 fx3, and I want to get a tighter cassette. Something like a 11-32, with jumps of two for the 6 harder gears, then by 3. So something like 11,13,15,17,19,21,24,28,32,

Which cassette and chain would you recommend that would also work with my current setup which is the following based on the trek website.


Shimano Acera M3000, 9 speed Size:
Shimano Acera SL-M3010, 2 speed
Front derailleur Shimano Acera T3000, 34.9mm clamp, top swing, dual pull
Rear derailleur Shimano Alivio M3100, long cage
KMC X9 chain

jimc101

What is the matter with your current setup?

If you want an 11-32, all of them are likely to have the same ratios, research to confirm, but generally if you choose a range, all the cassettes available for that range will be the same ratio

Iride01 

You generally don't build a cassette with custom cog sizes anymore. So you look for one that matches closest to what you want.

So just look for Shimano and other brands that are compatible with Shimano and find the 9 speed cassette that you wish to use. Though on your DR, you probably shouldn't put lower than a 32 tooth low cog on it to stay within the specs of your DR.

If your current chain isn't showing wear, then you could just shorten it if you go to a 32 cog, but if you only go to a 34 cog, it might shift well enough without shortening it. Or just buy any 9 speed chain you like the looks of.

SoSmellyAir

Rear derailleur specifications here: SHIMANO ALIVIO Rear Derailleur SHIMANO SHADOW RD 9-speed | SHIMANO BIKE-EU

Cassette options here: Shimano Alivio CS-HG400-9 Cassette (Silver) (9 Speed) (Shimano/SRAM) (11-32T) - Performance Bicycle (performancebike.com)

The last three (11-32, 11-34, and 12-36) are squarely within the RD specifications; the 11-28 will most likely work as well.

Or the 11-30 version: Shimano Sora CS-HG50 Cassette (Silver) (9 Speed) (Shimano/SRAM) (12-25T) - Performance Bicycle (performancebike.com)

Which also falls squarely within the RD specifications.

The Shimano CS-HG400-9 cassette has the following cogs: 11-12-14-16-18-21-24-28-32.
The Shimano CS-HG201 cassette has the following cogs: 11-13-15-17-19-21-24-28-32.

Shimano Alivio CS-HG201 Cassette (Silver) (9 Speed) (Shimano/SRAM) (11-34T) - Performance Bicycle (performancebike.com)

Awesomeguy is just saying he prefers the latter cog spacing.

rm -rf

Your bike has 30 / 46 chainrings, I think.
The two 9 speed cassette choices, in Mike Sherman's Gear Calculator. This chart shows mph speeds at typical flat road cadences for each gear combination.
The differences are fairly minor, either configuration would work okay. Both have 21-24-28-32 for the four largest cogs.

~~~~~
11-12-14-16-18-21-24-28-32.
This cassette is slightly better for evenly spaced shifts at the faster end of the cassette. But that's cross-chained, to be avoided.


~~~
compared to:
11-13-15-17-19-21-24-28-32
This looks a little better to me.
The large chainring has good spacing between shifts from around 12 mph to 20 mph. Good.
The small chainring has close shifts until it's cross-chained -- good.
A rider would spin out at over 30 mph (on a downhill) which is fine -- just coast on steeper downhills anyway.


~~~~~~~~~~~~~~

Compare to the bike's original 11-36:

11,13,15,17,20,23,26,30,36
The advantage is some one more low gear for steeper hills. But the tradeoff is wider shift gaps at more typical flat road speeds.
The difference isn't extreme, though. Many riders would be happy with either a 11-32 or this 11-36.

Kontact 

I would recommend any Shimano, SRAM or Sunrace cassette that it the least expensive for the gearing you're looking for. Bonus points for a more rust preventative silver finish. The cheap stuff shifts great, is durable enough and is often easier to clean. The kind of bike you have isn't going to benefit from paying for lower weight.

MudPie

For 9 speed, I'm a big fan of SRAM cassettes and chains. Look for the 9XX series of cassettes and chain and see what fits your pricepoint. Shimano is a fine product but I like to spread the wealth. One big advantage of a SRAM chains is they include a reusable masterlink that can be installed and removed with your fingers. Shimano 9 speed chains require a one-time use pin to connect the chain.

sweeks

True, but a "no-tool" master link made by another brand may be used with a Shimano chain as long as it's for the same "speed" chain. Examples I'm familiar with are KMC ("Missing Link") and Wippermann ("Connex").