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  1. #1
    Senior Member rykoala's Avatar
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    Gritty front hub- What did I do wrong?

    The hub is a Deore LX (HB-M570) MTB hub. I bought the wheel new about 2 years ago. Its not been serviced, but I haven't noticed any problems until now. I pulled the hub apart tonight and cleaned all the ball bearings, and cleaned all the grease out of the hub and off the cones. I regreased it with marine bearing grease (I have tons of the stuff) like I do all my other hubs (and bottom brackets, and head sets) but the thing is still very gritty. Is the hub trashed? No amount of adjustment will make it smooth. I've rebuilt hubs like this before without problems.

    Thanks!

  2. #2
    D.G.W Hedges mrhedges's Avatar
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    Did you make sure to replace all the bearings? A missing bearing might account for some grittyness. Also look for pitting. You can do this by taking the bearings out cleaning the grease out then run a ball point pen along where the bearings were sitting (I think its called a bearing race?) if you feel alot of roughness then the hub could be pitted. This means that dirt and water got into the hub creating excess friction and this wore away little bits of the hub. What was the condition of the hub when you first took it apart? When you say gritty how bad is it? can it spin? After two years it might never spin like it was new but it might still work fine. This is just an educated guess I've only been wrenching for about a year so perhaps a more experienced person might know more.

  3. #3
    Senior Member rykoala's Avatar
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    Thanks for the info. I have to ride it for the next 2 weeks, no time to wrench. It spins, works ok. I don't know why they'd be missing a ball... its never been apart. I will replace all the ball bearings in a couple of weeks.

  4. #4
    Just ride. roadbuzz's Avatar
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    If the bearings and races are okay, then the cones are too tight. But since no amount of adjustment fixed it, I'm guessing the races are f'ed. The damage was probably caused by having the cones adjusted too tight, grunge getting into the bearings (how dirty was the grease?), or letting the bearings get dry (unlikely, IMO).

  5. #5
    Life is short Ride hard
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    Bearings getting dry not impossible it takes a long time I am pulling some bikes apart from the 60's and their headsets have dried out bearings
    The Ferrari ('05 Bianchi Forza) had a flat (Stupid Glass) the Japanese wagon ('77 Nishiki with Arkel Utility Basket) was in the body shop (On my bench being repainted...repent ye rust)
    so I took the SUV ( Cannondale V2000 Active 100SL)

  6. #6
    Senior Member rykoala's Avatar
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    They weren't dry at all. They were very clean, too. No dirt. I'll follow up when I have time to tear into it. Maybe tomorrow night?

  7. #7
    Si Senior dbg's Avatar
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    Gritty is how it feels when they are too tight. You want it as loose as possible but with as little sideways play as possible. QR skewers pull it a bit tighter, so you need to leave room for that.
    David Green, Naperville, IL USA "The older I get, the better I used to be" --Lee Trevino

  8. #8
    Senior Member rykoala's Avatar
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    I've adjusted hubs many times before. I really do know how tight they are (and aren't) supposed to be. I didn't overtighten it. I'll tear into it tomorrow night and see what might be wrong. Might stop at the LBS on the way home and grab some new ball bearings.

  9. #9
    Senior Member rykoala's Avatar
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    Ack, that sounded really onerous. Sorry. Shouldn't type when I'm in a hurry..... Thanks for the advice folks!

  10. #10
    D=RxT
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    I think that the 570 LX has metal shields pressed onto the cone. If these were shifted during maintenance they might be rubbing, causing a gritty feel.

  11. #11
    Senior Member rykoala's Avatar
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    I think you may have hit the nail on the head! I did notice during maintenence that the lip that fits into the metal shield was bent a bit. I don't know how it happened. Weird. maybe its always been like that. I'll straighten it tomorrow. I wish I had thought of that!

  12. #12
    Senior Member rykoala's Avatar
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    Well, mrhedges was correct. Missing balls in the hub. The hub *came* with only 9 per side, and it takes 10. I scavenged two ball bearings from another hub that is in the middle of being rebuilt, and put those in. Now, its as smooth as can be expected. Thanks for the help everyone!

  13. #13
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    Quote Originally Posted by rykoala
    Well, mrhedges was correct. Missing balls in the hub. The hub *came* with only 9 per side, and it takes 10. I scavenged two ball bearings from another hub that is in the middle of being rebuilt, and put those in. Now, its as smooth as can be expected. Thanks for the help everyone!
    I've heard that it's best to avoid mixing and matching ball bearings from different lots - so that they're all about the same size and wearing evenly. It may not matter as much with grade 25 balls as with grade 200 ones.

  14. #14
    Senior Member rykoala's Avatar
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    Good idea. I'll go buy all new ones this weekend and rebuild it. Again.

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