3

This needs some explanation. I have a Cannondale CAAD13 road bike, which has only 2000 km on it. Unfortunately, the freehub already developed a lot of play and noise. The bike came with a Formula freehub, which isn't really serviceable. I replaced it a few days ago. To access the inside hex nut of the freehub body, I had to hammer out the hub bearing on the non-drive side, as there wasn't enough space to fit the hex wrench otherwise. After replacing the freehub, I had to hammer the bearing back in. I couldn't figure out how to use a bearing press or puller because the freehub body was always in the way, and I didn't want to counter-press on it. So I tried to be as careful as possible.

Unfortunately, I had to hammer on the inside race of the bearing since there wasn't enough room for my flat screwdriver to reach the outer race. Now, the bearing on the non drive side feels rough, which might have been the case before. As a last resort, I removed the seal of the cartridge bearing, cleaned it with WD-40 (carefully avoiding other areas), but it didn't help. I hammered the bearing out again and ordered a new one. When installing the bearing the first time, I probably angled it slightly. The paint in the hub is removed on one side, and I think it was a little easier to tap the bearing out compared to last time. Have ruined my hub, or can I still install the new bearing when it arrives? I feel a bit foolish for this mess, but I needed to replace the freehub. I'm also looking for a second set of wheels but would love to keep these as a backup.

scratched hub inside scratched hub inside with hex hub with installed bearing

Improve this question
1
  • To give a few more details: There's no edge or material buildup where the paint is removed. Still I ran 1000 sandpaper over it to be absolutely sure. Also I measured the inner diameter of the hub shell and got max 0.05 to 0.1 mm difference where the paint is removed. And I checked with a jewelers loupe for any cracks but couldn't find any. Anything else I can do?
    – conste
    Commented May 29 at 19:45

2 Answers 2

Reset to default
5

For the condition of the hub: Most of the time when something like this happens, it's cosmetic and won't interfere with the bearing being able to press in properly. Remove any slivers that got created, smooth the chamfered areas back out if they got messed up, grease the bore, and press in the bearing. If you did find the bearing pressed only loosely or not at all, degrease the bore and do it again with retaining compound and it will likely be fine. This isn't often needed though.

You've expressed reluctance to use the DS bearing as a surface to press on with the other side of a bearing press. It's not totally clear which hub this is and how it's put together, but it's pretty much universally true that as long as the thing you're pressing it with against is making contact with the outer race, it's not going to hurt anything. Here I'm pretty sure that's going to be the DS main bearing and the freehub has another set or two inside the FHB. If that's true, it definitely won't hurt anything. The outer race of the main bearing is rigid with the shell.

However, even if you really couldn't touch that bearing with anything when you pressed in the NDS, you would still have the perfectly fine option of cradling the DS flanges against a padded surface (like open vise jaws with rags over them, not clamped just loosely cradling the hub flange) and tapping in the NDS bearing that way. The classic way of doing this is use the old bearing as a drift. If you had to do it with the axle in place, put a deep socket over it to contact the drift, choosing one that itself makes good contact with the outer race, then tap on the socket with your hammer.

Improve this answer
4
  • Thanks for this thorough explanation. I added some more details as a comment to my original post. The surface of the hub shell feels pretty smooth still and I also ran some 1000 sandpaper over it to be be absolutely sure there are no edges. Measuring with a caliper also shows no real size difference. Maybe 0.05 to 0.1 mm less where the abrasions are. Someone told me in an ideal world this hub should be replaced because the abrasions and deformations will only get worse over time. Do you think this is a real concern?
    – conste
    Commented May 29 at 23:49
  • 1
    @conste No, it sounds like that person was somehow conflating what you have going on with a damaged cup on a looseball hub, or something. Your hub will be fine as long as the press fit still works correctly, or if retaining compound can do the job if not.
    – Nathan Knutson
    Commented May 30 at 4:10
  • @conste And either way (although Nathan is right), you can just keep riding until a problem actually develops. You were gonna replace the hub regardless.
    – MaplePanda
    Commented May 30 at 19:29
  • Pressing in the new bearing was still perfectly fine. But the bearing press made the whole process so much easier and I avoided any more damage with it. Thanks for the suggestions!
    – conste
    Commented Jun 7 at 7:00
0

Try using a long bolt, two washers and a nut. tighten gently until you've cinched the bearing in. Yeah, you probably ruined a bearing, but don't hammer on new bearings.

Improve this answer
12
  • That won't work because I need to have the freehub body installed when inserting the bearing on the non drive side. Using a bearing press or long bolt I would need to have the washer locking against the freehub body and as a result crushing the inside bearing in the freehub. I can't get a press to rest against the hub on the other side.
    – conste
    Commented May 29 at 21:06
  • Why couldn't you grind a body washer to size and use freewheel axle spacers for stack height?
    – some dumb guy
    Commented May 29 at 21:43
  • 1
    @conste If this is the hub I'm thinking of, the outermost bearing on the freehub body is the DS main hub bearing. It's always moving when the wheel spins, right? If that's true, it's fine to press on it with a press, it's the same thing as how you would replace it if you were changing it out. As long as the force is going through the outer race it can't hurt anything.
    – Nathan Knutson
    Commented May 29 at 23:04
  • 1
    General advise is to never put stress on the bearing balls or the races. That means to only put pressure on the outside of the bearing if that's the part you're pushing into a frame. By putting a washer and bolt through, you're going to stress the inside, not the outside. Instead, find a socket slightly-smaller than the OD of the outer race and use that with the threaded rod and nut. Its possible the inner bearing is wider or flush with the outer, so a washer will press in the wrong place.
    – Criggie ♦
    Commented May 29 at 23:39
  • 1
    @conste No. Think about what's happening when the wheel is tightened into the frame. The design of the hub has to protect the freehub mechanism from compression to the main bearing binding up the freehub's movement, that's kind of the whole game. If you were to take apart the freehub, you'll find an inner part that becomes rigidly attached to the shell with the nut you had to access from the NDS. The DS main bearing is pressed in to that inner part, and the outer part of the FHB rides on it via the freehub bearings.
    – Nathan Knutson
    Commented May 30 at 4:17

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.