Why are Shimano hub bearings tight from the factory?

[jb]

90% of the hubs will not be used long enough for the owner to ever notice any wear.

[Gattonero]

90% of the hubs will not be used long enough for the owner to ever notice any wear.

and the others are always on time to use the main hub feature: ease of adjust

[Brucey]

90% of the hubs will not be used long enough for the owner to ever notice any wear.

and the others are always on time to use the main hub feature: ease of adjust

I dunno about that; I see a lot of hubs with failing bearings and the causes are always the same;

1) bad adjustment (i.e. never been touched from the factory, or adjusted by someone who didn't leave any free play etc etc ) so that the cones are breaking up
and/or
2) not enough grease, and what there is isn't in any way proof against our climate.

I also see quite a lot of hubs where 'a repair' has been carried out using a generic axle kit; these hubs are usually wrecked beyond repair, (unless you are prepared to fit new cups). Using cones with the wrong profile and those crummy clipped balls is the quickest known way to ruin a hub...

Cone surfaces can start breaking up within a few hundred miles if they are left on factory settings. Very many cyclists (and even mechanics) think that this is 'inevitable' with certain types of hub because 'those bearings are crap' and so forth. This is very rarely the case, in fact.

cheers

[MikeF]

I bought a new QR Deore hub, and I could feel cogging as I turned the spindle. I imagine the hub life would be severely reduced had I ridden it like this. Now, either the manufacturer knows about this, but doesn't care, or they can't find or afford a solution. If they don't care, why do they invest any money in design and analysis at all? Why do they persist with using cup and cone bearings on the basis that they give a lower contact pressure, and a longer life? I'd be surprised if they couldn't find a process solution to measure play in the spindle. Even hand adjustment shouldn't take more than a few seconds if it was all set up in a jig.

Why on earth would you expect an adjustable component to be correctly adjusted from the factory??? I certainly wouldn't. However I would expect it to be properly adjusted if I were buying a complete bike or wheel from a shop, but my expectations and what I received may be different

[Gattonero]

90% of the hubs will not be used long enough for the owner to ever notice any wear.

and the others are always on time to use the main hub feature: ease of adjust

I dunno about that; I see a lot of hubs with failing bearings and the causes are always the same;

1) bad adjustment (i.e. never been touched from the factory, or adjusted by someone who didn't leave any free play etc etc ) so that the cones are breaking up
and/or
2) not enough grease, and what there is isn't in any way proof against our climate.

I also see quite a lot of hubs where 'a repair' has been carried out using a generic axle kit; these hubs are usually wrecked beyond repair, (unless you are prepared to fit new cups). Using cones with the wrong profile and those crummy clipped balls is the quickest known way to ruin a hub...

Cone surfaces can start breaking up within a few hundred miles if they are left on factory settings. Very many cyclists (and even mechanics) think that this is 'inevitable' with certain types of hub because 'those bearings are crap' and so forth. This is very rarely the case, in fact.

cheers

?
Number one, in a way, is what I'm saying.
Number two, is true sometimes but not always.

[Abradable Chin]

]Why on earth would you expect an adjustable component to be correctly adjusted from the factory???

The thing is, if half of all Shimano hubs self destruct soon after their initial use because of a human failing, but other types of hub using cartridge bearings are fine, then it's a bit of a puzzle why cup and cone hubs continue to be made for the mainstream consumer.

[MikeF]

]Why on earth would you expect an adjustable component to be correctly adjusted from the factory???

The thing is, if half of all Shimano hubs self destruct soon after their initial use because of a human failing, but other types of hub using cartridge bearings are fine, then it's a bit of a puzzle why cup and cone hubs continue to be made for the mainstream consumer.

Is there evidence for that?

Cup and cones have been used on bicycles since way before I was born, which is quite a long time ago. Even as a young boy I was told about adjusting wheel cones even if I didn't know much else about bikes. Cup and cones are simple, reliable, and have minimum friction and a long life (if properly adjusted!) which is probably one reason they are mainstream.

[Samuel D]

… then it's a bit of a puzzle why cup and cone hubs continue to be made for the mainstream consumer.

Don’t you go giving Shimano any ideas!

[Brucey]

cartridge bearings are pretty cheap these days; they are (if you are not too fussy) a commoditised product, churned out by the gazillion in near-fully automated plants all over the world. But.... if you are making millions, cup and cone bearings are probably still cheaper. And (for bicycles), better, I think.

There's probably not as much in it as there used to be, cost-wise though.

cheers

[jb]

Cartridge bearings from reputable manufacturers are, these days, cheap, extremely high precision, made from far higher quality steels than ever before & are assembled in as contamination free an environment as is practically possible. in a sealed environment they will outlast most applications.

Whilst cup and cones can also be high quality the human interaction in setting them up will in more cases than not result in a seriously compromised condition. I have `Hope hub's running on my best road bike for 3 years that did 15 years on a mountain bike before that and were originally bought second hand off the Hope race team; they have had the same cartridge bearings in them throughout. The Hubs may have been high end gear but the bearings they use are the same stock bearings sold through out industry for all sorts of purposes.

One area they do fail in is jockey wheels, because cartridge bearings are not meant to run as a `single bearing'; they should always be used in pairs (this keeps them square and prevents the lip seal from lifting off its mating surface and letting in foreign bodies). also slight movement applications such as head sets are bad because the lubricant rarely gets chance to form a film to separate the metals.
It is IMO a fallacy to say that cup and cone are better than cartridge bearings because they simply aren't ,however they may fail due to other reasons such as misalignment but that's not the bearings fault.

[Keezx]

One area they do fail in is jockey wheels, because cartridge bearings are not meant to run as a `single bearing'; they should always be used in pairs (this keeps them square and prevents the lip seal from lifting off its mating surface and letting in foreign bodies). also slight movement applications such as head sets are bad because the lubricant rarely gets chance to form a film to separate the metals.

Can't quite agree with that, I use exclusively Tacx jockey wheels and the plastic teeth are usually worn out before the bearings fail.

[Brucey]

one reason I think that cup and cone bearings are often better for bicycle applications is that they usually have (size for size) a higher static load rating than a typical Conrad style deep groove bearing. This is very simply because the Conrad bearing only has about half the number of balls in than it could do if it were designed/manufactured differently. There is also the issue that where a cone or a pedal spindle can carry out a dual role (adjustment and/or cantilever support as well as being a bearing surface) whereas a cartridge bearing can only carry out the one task. The angular contact of a cup and cone bearing is also advantageous in many applications; hubs, pedals, BB bearings etc can all see significant lateral loading which a deep groove bearing is less able to withstand.

Cartridge bearings have a few operational difficulties too; the most common bearings have a grease fill that is suitable for high speed running; bearing manufacturers will make special bearings with more grease in for low speed running as per bicycles, or grease with better corrosion inhibitors in, but because these cost tuppence hapenny more, they are not widely used. Also the tolerances of the housings and shafts must be many times better than those for cup and cone bearings, and when (say) wheels are built, the spoke loads tend to throw the whole thing out of kilter; it is rare for the bearing preload to remain correct in a built wheel's hub. When the bearings do wear, there is usually no adjustment, so they are scrap. [There have been a few notable exceptions to this, but it is not a common or popular arrangement to have cartridge bearings with a good adjustment provision. ]

When cartridge bearings are still new and operating under full preload condition, the slightest thing can cause them to nip up. Commonly a small amount of water inside a bearing can cause enough corrosion (whilst the bike is stored) to cause the bearing to seize up entirely. HT-II bottom brackets commonly fail because of this; I think it is the cause of the 'mystery groove in the LH end of the spindle' syndrome; usually the bearing starts working again after a while but by then the shaft can have been damaged.

If you seek to utilise the best features of both cartridge and cup and cone bearings, you might end up using full-complement angular contact bearings. WTB used to do this in their hubs, for example. These bearings have many of the benefits of cup and cone bearings (adjustable, high static load rating, etc) whilst gaining much of the benefit of using a volume-manufactured industrial part too. However the economies of scale don't work out so well, thus the bearings are still significantly more expensive, and so are the hubs etc into which they fit; there are more parts to make once you have an adjuster.

There is of course no such thing as perfection, so it is probably a question of which kinds of compromises suit the end user best.

BTW cartridge bearings in jockey pulleys may be doomed to eventual failure because they are not meant to be able to rock like that, but IME they usually fail for more prosaic reasons, like they get a load of crud in the bearings. I don't think I've managed to wear out a jockey pulley ball bearing that didn't get contaminated first. I have seen and owned multiple sets of tacx pulleys where the bearings failed BTW.

cheers

[jb]

One area they do fail in is jockey wheels, because cartridge bearings are not meant to run as a `single bearing'; they should always be used in pairs (this keeps them square and prevents the lip seal from lifting off its mating surface and letting in foreign bodies). also slight movement applications such as head sets are bad because the lubricant rarely gets chance to form a film to separate the metals.

Can't quite agree with that, I use exclusively Tacx jockey wheels and the plastic teeth are usually worn out before the bearings fail.

They certainly can outlast the teeth if used regularly but let the bike stand for a while after being used in wet conditions and they will seize up. This is not always detectable as the bearing simply spins on the shaft. Hardened bushes are far better for this application.

[Samuel D]

Hardened bushes are far better for this application.

But they consume an extra ~0.5 W each in typical operation. On a bicycle aimed at speed, whether in a race or to cover ground quickly, that [very slightly] matters.