My road bike's freehub has an issue - the outer part of the body has about 1mm of play against the axle, resulting in a wobbly cassette. The freehub still functions but it needs replacing.

It's a Giant part similar to FH06KA-401, which is the right part for my bike according to this list. It attaches to the hub with an 11mm hex fitting. The hub has cartridge bearings and the axle is a QR setup with cone and lock nuts at either end.

I followed these steps to remove the freehub:

  1. Remove the cassette
  2. Remove the non-drive side cone nut.
  3. Tap the NDS end of the axle pretty hard with a rubber mallet until it fell out of of the drive side. The DS end of the axle still has a cartridge bearing and cone nut attached. The NDS cartridge is undisturbed in the hub.
  4. Unscrew the freehub with an 11mm hex key and a length of tubing for leverage. It was on really tight.

At that point I tried to fit my new FH06KA-401. It didn't fit into the hub body. I can't find much data on Giant hubs so I think I need my Giant dealer to find and order the right part. They're closed until next week and I have a bike fit in a few days so I decided to reinstall the old freehub for now.

I started to follow the steps in reverse:

  1. Insert the freehub and tighten hard.
  2. Re-insert the axle by pushing it through the freehub body and tapping with a rubber mallet until it sits snug.

At this point I saw the the axle doesn't spin as freely as I would expect. If I flick it, it makes maybe one rotation. In contrast my front axle spins a few times. I put the cassette back on just to check and as I expected it's like pedalling through treacle.

I've now realised I didn't think through how to reinstall the axle, and I can't find much help online for this type of hub.

Could this be because the DS bearing is no longer fitted tight? do I need a press? Or the axle not engaging properly with the NDS bearing? Or something else?

Should I just give up and wait for the Giant mechanic to take a look?

Thanks for any advice!

  • Sounds like you're dealing with a Thru-axle set up, probably? I note this line within the description of the freehub model you've linked to, "For sealed bearing hubs - Does not fit all models of the above, e.g. thru axle hubs."
    – Jeff
    Jan 7, 2020 at 6:52
  • A further thought would be that a hub overhaul involving cartridge bearings calls for the bearings to be pressed in. While a mallet and drift are acceptable options, care must be utilized to avoid damage of the bearings, especially the inner race. Inspect closely the DS cartridge which came out with the axle. I'd prefer to reconstruct the hub with both cartridges off the axle and pressed into the hub, then deal with the axle/cone nut/spacer assembly.
    – Jeff
    Jan 7, 2020 at 7:09
  • @Jeff Oops, good point. I've edited to say it's QR.
    – joews
    Jan 7, 2020 at 7:54


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