Using this video I determined that I needed the FR-5.2 tool. I.e. the tool fitting rotates with the sprockets, the rear derailleur is a Shimano Deore XT.

However, the tool doesn't quite seem to fit. The splines line up and I'm able to rotate the cassette, but it doesn't descent properly and I feel like I would strip something if I'd try to rotate it with more force. If I try to push the tool in with more force, nothing seems to happen. Is the tool supposed to fit this snugly?

The Bike is a 2019 YT Jeffsy

Am I using the right tool? Is there something I'm missing? pic1 pic2

  • 1
    Hi, welcome to bicycles! You can check how deep those slots actually are with a nail or piece of wire and gauge how much engagement you're getting. It's possible they're a bit gunked up, but if you're getting 80% engagement you're probably fine. Because riding force winds the cassette on, it can be really tight.
    – DavidW
    Jan 2 at 14:12
  • 1
    Also, the torque spec is high to begin with. I used to have an adjustable wrench with my cassette tool, and it was hard because it would slip.
    – Weiwen Ng
    Jan 2 at 17:46

2 Answers 2


With the odd state the cassette is in, it's hard to discern everything happening here - it appears this is an XD Eagle cassette that's been somehow dismantled while the big cogs are still mounted.

Sometimes it happens that the spatial relationship between the drive-side hub endcap and the lockring doesn't come out quite as intended, and tools don't engage the splines properly. You're right to be cautious because stripping the lockring is bad news.

If you can get a little engagement but you're worried about it slipping out under force, you can often make it work by holding the tool on with something. Some examples could be threaded rod or a solid rear axle and nuts, or the bike's own thru axle and hanger (which you'd have to temporarily remove). (The FR 5.2 may not have a >12mm hole without modification though).

In some cases you can also solve this by getting the DS endcap out of the way completely if it's a slip-fit and isn't obstructed by the lockring, though often it will be.

It's possible for this to happen because the drive side endcap isn't engaged fully on to the axle somehow, so it's out further than intended and is obstructing the tool. How you'd address this depends on how the endcaps and/or tool fittings on your hub work, i.e. whether either or both are threaded.

If the tool is almost able to get in but not quite, there's the possibility of either modifying it or hunting for a thinner one, which do exist. Obviously it doesn't have a lot of material to give, but almost being able to get on anyway implies that even taking 0.02mm with sandpaper could be enough.

Even if the DS endcap can't be removed without getting the lockring off first, there may be options to give it wiggle room that may buy you a little more clearance. Again depending on the hub design/layout, this would be either removing the axle through the NDS side (probably requiring taking out and then replacing the NDS bearing) or removing the freehub body and endcap together as a unit.


So the solution ended up being rather simple. The holes in the freehub were a bit dirty. I was able to get it in using a few very light hits with a hammer.

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