Every cassette will come to a point where it will need to be replaced. You may simply want to try new gears. You may need to switch between spare wheels if racing. Either way you may need to remove your cassette in order to do this. For many the question instantly arises...How do you do it? 

Get your dad, boyfriend, husband, friend, brother, uncle...etc to do it? No. You really can do it yourself. As daunting as those shiny cogs and tools look, the process isn't as difficult as it may first appear. Removing a cassette yourself will also be kinder on your bank account. 

The jargon and the components may seem a little daunting at first, but if you just take the time, read, think, look at the images, read again you can do it.


In this article we talk you through how to remove your cassette and fit a new one. We specifically focus on:

1) re-fitting a standard mountain bike cassette with a Hope 40T-REx; and

2) re-fitting a Hope Cassette.


Why choose to fit a 40T-REx? Most standard mountain bike cassettes have a gearing of 11-36t, which provides a good range of gears if you have two rings on the front. If you are switching to a more modern front single ring set-up you may find the traditional 11-36t gearing a little difficult and need more "room to spin" on the hills. Including a 40t cog in your cassette set-up is a much cheaper way to upgrade your gearing.

How to Install T-Rex

- Firstly ensure your rear derailleur (mech) can cope with the increased sprocket size. Check the manufacturers guidelines if you are unsure - this will usually be SRAM or Shimano.

- Shift the rear derailleur to the smallest sprocket to make wheel removal easier, take the rear wheel out of the bike, and remove the QR skewer or Axle. 

-Wrap a chain whip around one of the middle sprockets in the direction of drive, so you can apply counter-rotational force, then using the lockring removal tool wind out the cassette lockring. 

- Once the lockring has been removed slide the cassette off the freehub body (the part with groves on attached to the wheel). 

- The Hope T-REx Expands an 11-36t cassette only,  if your existing cassette is this ratio you can use it, if not a new cassette will need to be purchased, and possibly a new chain depending on wear.

-Remove and discard the 17T sprocket ('17t' will be grooved on the cog) and spacer, other combinations are also possible - but this is recommended.

- Slide the 40t T-REx on to the splines of the freehub, noting the large spline for location - keep spinning the T-REx around the freehub until the correct grooves meet each other and it slides on freely. Then install the rest of the cassette, with the removed sprocket. 

-Re-fit the lockring and tighten using the lockring tool to manufacturers guidelines. 

-Re-install the rear wheel into your frame- shift the derailleur to the 40t sprocket, you may find your chain isn't long enough for the new sprocket - if this is a case extend the chain with spare links, or measure and install a new chain.  

-With the rear derailleur shifted into the large 40t sprocket adjust the b-tension screw of the derailleur so the top jockey wheel sits as close to the sprocket as possible without touching, usually between 5mm - 8mm.

- Check through your gears and go ride!


How to Install Hope Cassette

- Remove the existing cassette using the procedure outlined above, remove the drive-side end cap (the side of the wheel with the cassette on) from the free-hub using a pair of pliers, then remove the freehub body by pulling it away from the axle.

- Ensure the freehub spacer is still on the axle (1mm or 2mm spacer depending on hub), then install the new Hope freehub by sliding the body on to the axle and engaging the pawls - then using a freehub tool push downward or tap with mallet to seat the seal into the hub body. Do not install the end spacer yet.

- Locate the splines of the Hope Cassette on to the freehub and slide the cassette on to the body, you may need to locate the internal cassette spacer by nudging it to one-side when sliding on the cassette.

- Install the lockring and tighten to 70 N.m, finally install the new (gold) driveside end cap that suits your axle setup.

-Re-install the rear wheel - shift the derailleur to the 40t or 44t sprocket (as applicable), you may find your chain isn't long enough for the new bigger cassette - if this is the case extend the chain with spare links, or measure and install a new chain.  

-With the rear derailleur shifted into the largest sprocket adjust the b-tension screw of the derailleur so the top jockey wheel sits as close to the sprocket as possible without touching, usually between 5mm - 8mm.

- Check through your gears and go ride!