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To change your gears you'll need to change your rear wheel sprockets; here's how

If you want a different range of gears such as lower gears for a holiday in the mountains or tighter gears for racing, the easiest way to achieve that is to change the sprockets on your rear wheel. Here's how to do it.

Sprockets mount on a splined cylinder on the rear hub, called the freehub body. The collection of sprockets is held in place with a lockring.

Modern shifting mechanisms like Shimano's Hyperglide and SRAM's PowerGlide chain-and-sprocket combination rely on correct alignment of shaped teeth and contoured shift gates in the sprocket. To keep this alignment right, the splines on the freehub body are uneven, with one spline larger than the others, so there's only one way the sprockets can fit.

Removing a cassette is the only worthwhile way to clean it. Do so as often as you feel like getting grubby, if you ride in the winter and dirt regularly then it could and maybe should be a weekly thing.

Our guide below shows you what we believe is the best method to fit and remove cassette sprockets. We've included a list of the tools and materials that you will need to complete the job and in some cases where you can buy them. If there are others that you prefer then feel free to let everybody know in the comments.

Tools & Materials

Chain whip and splined cassette tool.JPG

Chain whip and splined cassette tool.JPG

 

The sprockets may be collected together in a number of different ways. In inexpensive steel cassettes each sprocket is a separate toothed disc. Most of the sprockets are held together by long steel pins, with the smallest two or three sprockets loose for separate fitting. While you're changing sprockets this is a good time to consider upgrading to a lighter cluster.

Most lightweight cassettes use one or more stepped alloy carriers for the sprockets which are usually heavily drilled and machined to remove every last gram of surplus material. On some high end cassettes aluminium or titanium is used in place of steel, especially on wide ratio models where the weight saving is greatest and individual tooth loads lower. The cassette pictured below is a SRAM model with the 36-tooth largest sprocket made of alloy while the other nine are steel.

Chain whip on.JPG

Chain whip on.JPG

1 Position the chain whip
Wrap the long loose end of the chain whip over the top of the cassette as shown so that it is pulling the sprockets clockwise. Engage the fixed portion of the chain whip on the lower portion of the same sprocket that the loose end is attached to. It's best to use one of the middle  to upper sprockets, just ensure you've got a good wrap on the sprocket. When it feels firm enough to place a decent amount of pressure on, you're ready to get the cassette removal tool fitted.

spline tool lined upJPG

spline tool lined upJPG

2 Insert the lockring tool
The cassette lockring tool is sometimes integrated with a handle like this one, or it may be a separate tool that needs an adjustable spanner to give leverage. The spines on the tool will match those inside the lockring. The tool handle (or spanner handle) should be positioned to be a reflection of the chain whip. So if you look at the two tools in their fitted state they should resemble clock hands at 'ten to two'. Make sure the tool and lockring are fully engaged before you apply removal pressure. The lockrings are often light alloy and it's very easy to tear the teeth.

apply opposite pressure to both.JPG

apply opposite pressure to both.JPG

3 Unscrew the lockring
With the chain whip is in position and lockring tool in position, apply downward force on both handles. The chain whip will stop the cassette (and freehub) from turning as the lockring tool unscrews the lockring and breaks its grip on the smallest sprocket. 

unscrew the lockring.JPG

unscrew the lockring.JPG

4 Remove the lockring
Once the lockring is loose, unscrew it from the freehub body. You'll see it come away from the cassette like this. Remove the chain whip and slide the tool and lockring out of the way. 

slide cassette from hub body.JPG

slide cassette from hub body.JPG

5 Remove the sprockets
in the case of this particular cassette, the top three sprockets (11, 13, 14) are loose and they slide straight off. The remaining seven sprockets are all mounted to an alloy carrier body, so they can be removed as one unit. Here you can see them being slid off the cassette body (the white bit). Occasionally they can be a bit stiff to remove if the cassette splines have bitten into the freehub splines. Grasp the opposite edges of the largest sprocket and give a pull and a wiggle at the same time to get them moving.   

clean freehub splines.JPG

clean freehub splines.JPG

6 Clean the freehub body
Freehub bodies get a raw deal in life, carrying all the load and getting precious little reward. When you get to see yours, give it a clean. 

Narrow wide splines.JPG

Narrow wide splines.JPG

7 Splines
Now you've got the splines in clear view, you can see that they're not all even in size and spacing, as mentioned above, so that the teeth always align as the manufacturer intended.

Line up cassette splines and hub splines.JPG

Line up cassette splines and hub splines.JPG

8 Fit the new casette
Here you can see the splined black alloy carrier of the replacement cassette going on. It's holding the four largest sprockets. The narrow/wide splines are clearly visible at the twelve o'clock position. 

Fit spacers.JPG

Fit spacers.JPG

9 Fit the top sprockets
Sprockets that are not permanently mounted to alloy carriers (and are therefore already correctly spaced) will have separate plastic or alloy spacers. These keep the sprockets the correct distance apart for accurate shifting. Sometimes these spacers are just plain rings (like the one pictured here), however sometimes they too have splines, though when they are splined they have a number of 'clocking' positions they can be fitted at any position.

sprockets should be just proud of the cassette body.JPG

sprockets should be just proud of the cassette body.JPG

10 Fit the last sprocket
The smallest sprocket, here a 12-tooth, should fit and its outer face be just proud of the outer lip of the freehub body, the white bit in this shot. This means that when the cassette is tightened down with the lockring all the sprockets fit together tightly. 

thread lockring on.JPG

thread lockring on.JPG

11 Fit the lockring
Screw the lockring into position with your fingers. The threads are quite fine and if the lockring is made from aluminium, they'll therefore be quite fragile. Take care not to cross them. The lockring should require only light force to turn it until it touches the top sprocket.

Tighten the lockring.JPG

Tighten the lockring.JPG

12 Tighten the lockring
Make the final tightening of the cassette lockring with the lockring tool. The official torque setting is 40Nm. We tightening it until we feel the serrations on the lockrings inner face binding with the serrations on the outer face of the smallest sprocket. 

Read more: the full archive of road.cc repair and maintenance articles

16 comments

Avatar
japes [85 posts] 2 years ago
1 like

nice to see you take good care of your tools  4

the state of that chain whip!

Avatar
. . [192 posts] 2 years ago
0 likes

It should be tightened to 40Nm, not 14Nm.   It's printed on the lock ring.    About 3 or 4 clicks in my (Shimano) experience.

 

Avatar
iso2000 [88 posts] 2 years ago
1 like

"torque setting is 14Nm". Think that should be 40Nm.

Avatar
StraelGuy [1402 posts] 2 years ago
0 likes

Or Approx. 30 ft/lbs in English money yes.

Avatar
Simon E [3299 posts] 2 years ago
0 likes

I bought a simple lockring tool that is held in place by the QR like this Park one:

//www.thetrailhead.co.uk/ekmps/shops/jockey/images/park-tool-fr-5-shimano-cassette-lockring-tool-629-p%5Bekm%5D190x172%5Bekm%5D.jpg)

Used with an adjustable spanner, it feels more secure as it can't slip out of the spline as I exert significant pressure on it... or is that a groundless fear?

Tightening locknut requires significant force, the 'clinking' sound of the notches catching is a good indicator.

Avatar
srchar [849 posts] 2 years ago
1 like

These articles are all well and good, but the various techniques are better explained to the newbie target audience by video, as demonstrated by myriad more useful clips on YouTube.

Also, there's a hell of a lot of difference between 14 and 40 Nm.

Avatar
mike the bike [1070 posts] 2 years ago
2 likes
srchar wrote:

 ..... Also, there's a hell of a lot of difference between 14 and 40 Nm.   

 

Not when I'm in charge of the spanner, there's not.

Avatar
mostly [69 posts] 2 years ago
0 likes

I feel the decathlon chain whip / tool is worthy of a mention. As you said its most effective chain whip you've used, I concur http://road.cc/content/review/152537-btwin-chain-whip

Avatar
srchar [849 posts] 2 years ago
0 likes
mostly wrote:

I feel the decathlon chain whip / tool is worthy of a mention

I was having a look at one of these last time I was in Decathlon, thought it looked like a great idea.  I didn't buy one as my current chainwhip works fine, but if you don't yet have one it looks like a far more elegant solution.

Avatar
Woldsman [250 posts] 2 years ago
1 like
japes wrote:

nice to see you take good care of your tools  4

the state of that chain whip!

 

Which is why I would personally recommend some sort of stout plastic toolbox and counsel against storing expensive equipment on a shale beach or similar.

Avatar
Benjamin Nickolls [62 posts] 2 years ago
0 likes

Could you add in here: if you've a high performance bike it's likely that the freehub body will be made of a higher grade, softer alunium than your cassette and as a result you might have some notching that will lock the individual cogs in place. To remove these you need to turn the cogs in the oppositive direction which will require either another chain whip (one to hold the cassette, one to turn the cog in the no-drive direction) or you can do it in the bike using the one whip to lock the cassette and the chain itself to turn the cog in the wrong direction. It shouldn't take much force and is unlikely to damage anything. 

 

Ta

Avatar
Man of Lard [343 posts] 2 years ago
0 likes
mostly wrote:

I feel the decathlon chain whip / tool is worthy of a mention. As you said its most effective chain whip you've used, I concur http://road.cc/content/review/152537-btwin-chain-whip

srchar wrote:

I was having a look at one of these last time I was in Decathlon, thought it looked like a great idea.  I didn't buy one as my current chainwhip works fine, but if you don't yet have one it looks like a far more elegant solution.

I had a chainwhip that "works fine" - the Decathlon doobry knocks it in to a cocked hat for utility though. Absolutely no risk of slipping and skinning your knuckles. Gave the old school chainwhip away to a ride buddy who wanted to borrow it...

Avatar
Roddders [17 posts] 2 years ago
1 like

A sprocket casette! Is that in case readers were looking at howe to change an 8 track casette?

Avatar
JonD [496 posts] 2 years ago
0 likes
. . wrote:

It should be tightened to 40Nm, not 14Nm.   It's printed on the lock ring.    About 3 or 4 clicks in my (Shimano) experience.

 

 

In all the years I've been taking off and refitting cassettes I'd never bothered measuring torque - again, probably about 3 clicks. But on checking one I'd fitted more recently, I'd guess I've probably never used more than about 12-15Nm. And I've never had one shift or come undone..

Avatar
ch [188 posts] 2 years ago
0 likes
JonD wrote:
. . wrote:

It should be tightened to 40Nm, not 14Nm.   It's printed on the lock ring.    About 3 or 4 clicks in my (Shimano) experience.

 

 

In all the years I've been taking off and refitting cassettes I'd never bothered measuring torque - again, probably about 3 clicks. But on checking one I'd fitted more recently, I'd guess I've probably never used more than about 12-15Nm. And I've never had one shift or come undone..

 

Some recent aluminium hubs are so poor in precision and so soft that the sprockets wiggle around and gouge the hub unless they are tightened down to very high Nm.

Avatar
aceinvisable [2 posts] 2 years ago
0 likes

So, I currently run a compact 50/34T with 11-32 cassett. Since taking up cycling my goals have now changed and I want the option to have tigher gears for faster rides. Once I have changed the cassett (as above) how much work is needed on the rederailer, I currently have a medium cage derailer. For example if I had a set of wheels for hillier ride and a set of wheels for flat fast rides would it be simple to swop out?