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I just overhauled some cheap bmx hubs. I installed new bearings and cones. Now I'm trying to get the hubs adjusted so that the bearings will last as long as possible.

I had always thought that leaving bearings even a tiny bit loose (be it bb, pedal, or hub) was one of the cardinal sins when it came to maintaining a bike. But reading this from Sheldon Brown put that in question:

If nothing you can do will eliminate both the binding and the play at the same time, it is better to adjust a little loose and accept a slight amount of play then to have the hub bind

This is the situation I'm in. Is a little bit of bearing play a legitimate option? Will my bearings wear down more quickly if they are slightly binding or if they are slightly loose?

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    A little loose will not cause damage, though it may cause handling to be less than perfect. Generally with hubs, though, you want them just a hair tight (after skewers are tightened, if you use skewers). This is known as "pre-load", and it compensates slightly for the fact that placing weight on the wheel spreads the cones apart. – Daniel R Hicks Nov 9 '14 at 2:13
  • Minor quibble: you should be trying to maximize the lifetime of your hubs, since they are the more expensive and harder to replace component. Moot here though because wear to one directly affects the other. – Darth Egregious Nov 9 '14 at 18:28
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    Some quick thoughts: 1) Impact load on the balls when the wheel wobbles 2) Smaller contact surface because fewer balls contact both rings. Probably those are insignificant and Daniel's comment about handling will be the only result. But if perfect tuning is impossible, I reckon loose bearings will wear out much slower than overtightened bearings. – Vorac Nov 12 '14 at 15:48
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A bearing that is adjusted too tight can actually seize completely. This happened to me once. I overhauled my front hub and tightened the bearing cones too much. Result: a front wheel that plain stopped turning at some point.

Too tight adjustment will exert more pressure on the cones and cups, and will probably wear out the bearings faster than too loose an adjustment.

For proper adjustment, the Park tool website has good instructions: http://www.parktool.com/blog/repair-help/hub-overhaul-and-adjustment

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    It should be noted that a bearing seizing up tight like this usually results from the locknut on the right-hand cone not being tightened enough, resulting in the cone being screwed tighter and tighter. If the opposite cone is not tight enough the cone gets looser and looser, though the effect doesn't "snowball" as it does on the right. – Daniel R Hicks Jul 25 '15 at 12:00
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One thing to keep in mind is that a hub that feels a tiny bit loose when out of the bike will likely have no play once you put it in the frame/fork. The clamping force on the axle nuts will tighten things up, removing the excess play.

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    This depends on several factors, mainly the nature of the axle. A solid axle does not get any tighter as nuts are tightened. A quick-release axle, on the other hand, is compressed slightly when the skewer is tightened. – Daniel R Hicks Jul 25 '15 at 4:07
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Years ago the weight weenie road racers used tae leave out a bearing in each hub, saving mebbe 100/150gms on bike weight. They never had problems! pack in more grease.

As you say, they're cheap hubs and more likely ye'll break them before they wear anyway.

  • It would be better if you used proper English grammar and spelling. As for racers (in general), they aren't exactly interested in the longevity of their equipment, so I don't think the "racers do it" is a good argument for someone who is primarily interested in longevity. – Batman Nov 12 '14 at 16:17
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    And it should be noted that one "standard" for how many balls should be in a bearing is "a full race minus one". This isn't exactly correct (depends on the amount of wear), but it's a rule of thumb that is not dangerous to follow. – Daniel R Hicks Nov 12 '14 at 16:39

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