I have a cheapish (okay - cheap) Shimano FH-M525-A MTB rear hub (QR, 10-speed). The freehub body has a fair bit of play so I want to replace it. There are any number of supposedly-identical replacements available on e.g. Amazon, etc., but I was thinking if there is a compatible one with more engagement points than the pretty-awful 16 I currently have, I might as well get that while at it. Something similar to a Deore -> XT upgrade for this part.

I see most Shimano MTB hubs now have either 32 or 36 EP's, which while not high-end would be a significant improvement on my 16. The freehub body I have is the Y3SP98110 (shown here as part of the hub). After much searching I've been unable to find any data to support confidently selecting a better alternative. It seems at this granularity of part (rather than e.g. the whole hub) there is not a lot of information going, especially on Shimano's site (as already noted here).

Does anyone know a part number for a compatible-but-better freehub body that I can search for?

  • Read this thread. mtbr.com/threads/… . Seems like a M756 will be step up in durability. Commented Jun 25, 2023 at 13:56
  • @WarrenBurton - thanks, that's a very helpful thread.
    – sellotape
    Commented Jun 25, 2023 at 15:24

1 Answer 1


Just to close this off...

At the time I looked into it quite a bit, and as the AliExpress link posted by @elad-schitrit implies from the number of options, I found that Shimano has over time made a lot of very-similar freehub bodies (even, it seemed, within 10 speed splined), each with potentially slightly different dimensions. Eventually I concluded it wasn't worth pursuing further.

The linked answer in my original question mentions many of the same concerns.

At some point I'll just get a new wheel with a better hub...

So I ended up servicing the freehub body instead, which turned out really well. No additional POE though.

Here a video if you want to go that way. I also needed to buy this tool, which wasn't exactly easy to use but did the job.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.