Tulok

Does anyone else have insights on this? I used to believe that it doesn’t matter very much. But I rebuilt a pair of 600 hubs with Wolber rims. I used a plastic abrasive wheel on the cones to a mirror finish. Reused the balls but I cleaned everything beyond thoroughly. Now I am in shock because I went from being the one who had to pedal in the paceline to coasting and braking not to hit the guy up front. No other changes. Is Sheldon correct?

Sheldon Brown:
“Do not be fooled because your hub may seem to have "just a little" friction. Frictional drag depends on the load on the bearing. When you are holding the wheel and turning the axle by hand, the only load is the weight of the axle set and the viscosity of the lubricant. When you are riding your bike, the load is the weight of you and your machine, and the frictional drag is increased by many times. You can feel the difference.”

https://www.sheldonbrown.com/tooltips/hubs.html

noglider 

OK so according to Sheldon, I'm wrong. Thanks.

martl

a bicycle wheel has a diameter of ~650mm and the hub bearing radius is ~12mm. This also is the lever ratio with which your system mass (bike+rider) of a rolling bicycle acts against a maybe not perfectly smooth bearing. You'll need very expensive equipment indeed to measure any differences for this.

mkeller234

Maybe? I get that the bearing load is greater when they are in use under full weight... but there is not really much you can do about that, is there?

Here is what I do... see if this rings true for anyone.

1) Adjust the cone till it binds, then back off a smidge.
2) Check the axle for up and down play by rocking it with my hand. Some play is expected and good.
3) Mount the wheel into the bike and tighten the QR skewer
4) Try to rock the rim side to side to see if the extra play in the axle is gone.
5) Adjust, readjust, readjust, swear, repeat.

The Golden Boy 

I’ve read that sealed bearing hubs will never be as smooth as high quality cup and cone hubs.

Both my old Avocet hubs and new Phil hubs both spin like greased Teflon butter sticks.

I just figured I must not know what “smooth” is.

Hobbiano 

Thats what I do.

Hobbiano 

I agree with this. For what its worth.

dddd

One consideration about bearing surface smoothness is that as the loading increases, the steel surfaces elastically conform to one another, essentially squashing down surface defects (i.e. high spots) toward the level of the low spots.

At the same time, flex in the balls forces them into a slightly oblong shape, which increases the interference contact force between balls in the loaded zone along perhaps one-third of the circumference of the bearing races. Contact here is between surfaces moving in opposite directions, so makes an argument for the use of flexible retainers which can reduce ball-to-cage contact forces and eliminate direct contact between adjacent balls.

I think we tend to view steel bearings as being hard and rigid, but under loading, all materials are elastic.

I think that when someone says that it's "how the bike rolls" that matters, it's not to say you can necessarily feel any difference while riding, but rather that it's the as-installed condition of adjustment that matters, after considering the QR's compression of the axle and the slight bending of the axle which (theoretically at least further shortens the axle and also rocks the bearing cones slightly off-axis, both of which could make the bearing turn tighter).

Often the well-used balls are still smooth and round, but this is hard to confirm quantitatively. Chromium balls tend to be "tougher" than the races they roll in.
Yet I find that using new Gr25 balls does occasionally solve a rough-turning axle even when the old ones still looked perfect.

Puzzling to me is how everybody's cup/cone hubs are shipped out with snug bearing adjustment that becomes VERY tight as the QR lever is applied. This applies to new hubs and the new bikes that they are spec'd on. I am certain that this greatly reduces the working life of the bearing surfaces. It seems unrealistic to expect finely-finished bearing surfaces to break in sufficiently over time so as to offset the shortening of the QR axle.

SamSpade1941 

My Phil Wood hubs that the Motobecane rolls on are butter smooth on or off the road.

As are my Ultegra hubs on the SOMA and the Neuvation hubs on my Ridley.

I could not spin them by hand and tell you which one was smoother. I just know the Phil hubs and the Neuvation hubs will never need cleaned and repacked.

i can’t say that for my Campy or Shimano hubs of any flavor .

machinist42

The G25 bearing balls I use have a Rockwell hardness in the 60s, while the races in my hubs are hardened into the 70s.

(Replacing the races is not only often not possible, when it is possible it is a pain in the b***s.)

noglider 

Yes, I can't figure out why bike makers ship bikes out that way. What could the rationale be? Lower labor costs for getting it right?

Bandera

See Post #14 in this thread.

-Bandera

Kuromori

What ball bearing races are hardened to 70+ HRC? It's hard to get that kind of hardening response from any steel. Off the top of my head 52100 or 440C are in the 60's as quenched. I really don't know what toughness has to do with bicycle ball bearings as I've almost never seen one crack, but generally speaking toughness tends to be inversely related to hardness for this kind of application.

Also as an aside heavy wheels are going to tend to spin for a long time because of the flywheel effect.

Salamandrine 

That's a pretty good description. First time I ever saw a Phil hub, it was described as smooth as campy. That was the perspective of the times. Nowadays we're spoiled by all these cheap cartridge sealed hubs.

Never heard that cup and cones were supposed to be smoother. I'd say campy vs Phil when new was a tie AFA buttery smooth. Phil axles don't break though. If you do trash the bearing, you have to send 'em back to Phil. BTW, Phil don't necessarily last forever with no servicing, but they can be rebuilt. The original flavor always got rusty middles, but that was just aesthetics.

Of course the hub friction is basically irrelevant. Practically speaking, people bought campy or phil quality because they lasted a long time. If you bought cheap hubs and rode say 15k or more miles a year, they aren't going to hold up.

Kuromori

It's not really smoother, but some people get the impression that cartridge bearings don't spin as easily when comparing cartridge bearings with contact seals to cup and cone without contact seals.

dddd

I guess that's where this "tradition" started, but how to figure out why it persists to this day?
The old truing stands with "cone" locators by now being pretty far off in the rear-view mirror...

The odd thing is how so much effort in terms of material quality, precision, polishing and sealing features is consumed, and then for the component AND bike manufacturers to leave them tight all the way to the customer.
(MANY Atom hubs were damaged during the first few hundred miles, not just because their races were of lower quality. They were left bloody tight as installed on millions of 1980's Schwinns, and that's just for starters. But they usually do ok in the long run if readjusted before much use.)

It's as if the attitude is that the customer only looks at the market-rated quality level of the components and cares not if the bike is assembled properly, i.e. "what they don't know won't hurt them".
I sound naive saying that, right?

I will say that it is impressive how long that an over-tight hub from Shimano can last!

.....And for anyone who has never done the QR axle-tightness test using a pair of thick washers or actual dropouts that aren't connected to a frame, this can/will be a real eye-opener(!!!) (thinking back to the first shop I worked in ca. 1978, the owner showed me this, and also how the Sunshine Gyromaster hubs shipped with the Fujis seemed immune to it).

Salamandrine 

No bike I ever assembled in my LBS days ever came with hubs adjusted. It was assumed that a professional mechanic would adjust them properly in the shop during assembly. It's time consuming. Not worth doing at the factory if it drives up cost. Put the parts together, snug 'em up and ship 'em.

If you bought a set of hubs a la carte, those never came adjusted either. If you can build a set of wheels, you should know how to adjust your own hubs, right?

BFisher

I think about the consumer market as a whole, and would agree that most people don't know or even consider things like bearing adjustment, or lubrication. From a manufacturing standpoint, too tight may be better than too loose. Time is money. Wobble or slop is instantly noticeable, but binding may not be when the whole mass of the object is pedaled down the road. Or, maybe I'm misunderstanding.

dddd

I get what you're saying about the a-la-carte hubset, it comes with an "inspection adjustment" that lets the savvy enthusiast or mechanic get a "read" on the bearing quality, so makes sense that way.

But consider that when buying a motorcycle, this would be like having the final drive chain set up too tight, such that the chain severely over-stressed the chain and output shaft bearings every time that the rear suspension moved through it's travel arc.
But with motorcycles leaving a shop, such an oversight is extremely rare. I've seen it, but it is quite rare!
So with bikes often costing as much as motorcycles, and with each carrying comparable warranties, what is it about the bicycle industry that allows bikes out the door with over-tight hub bearings?

Like I said, I find this puzzling, and have for many years.

dddd

You're right of course, that because the hubs being tortured doesn't often get noticed.

So, unlike my analogy to the motorcycle setup, the bicycle hub maladjustment is more of a passive neglect item rather than an act of maladjustment.
Really then, the issue would seem to be simply a dereliction of duty on the part of the final point of sale, yet the fully-built and ready-to-go wheelsets with cup/cone bearings are sold this way whether at a shop or as an online purchase by the end user. At least the higher-end wheels are adjustable in-situ after installation, and with instructions (if not tools) for such typically included with the wheel package.

cudak888 

The too-tight hub cones are much less likely to hurt anything other than a bearing surface.

This is a guess, but from the consumer's POV, it is much easier to detect a wheel that's a tad wobbly because the automated assembly didn't get the bearing preload right, rather than one that is just a hair too tight. Thing is, the machine - unlike mkeller234 and other human mechanics - is incapable of "readjust, readjust, swear, repeat."

-Kurt

Salamandrine 

I think I understand now where you're coming from on this, and you're right, from that point of view it's kind of ridiculous. I'm not sure if there were strategic legal reasons that bikes are shipped this way. Seems like there's a bit of trying to spread or shift the blame in case there's a problem. Certainly it saves the bike companies money.

Nothing on a bike when it is received by the bike shop is set up or adjusted. It isn't just the hubs. They come in a box basically just assembled enough to stay in one piece. It's a frame and some parts bolted to it. The headset and bottom bracket need adjustment. The cranks typically would often get pulled and reinstalled. Brakes had to be hooked up and adjusted. Wheels had to be trued up and get their cones adjusted. Dropouts were checked. Derailleurs set up and adjusted. Cables all pulled and greased. Etc etc.

Clearly the LBS doing the work mattered a great deal. Less scrupulous dealers would skip as many set up procedures as they could get away with.

noglider 

I've worked in a few shops, and in only one of them were we required to adjust all bearings to the right preload, and I mean headset, BB, and wheel cones. The other shops didn't ask us to do it, and when I brought the practice to some others, after having learned it, the owners told me to stop because I was costing them time and there isn't enough reason to invest it, as problems that they prevent are rare enough. That one shop knew that it would have a few customers who ride a lot, and they'd be unhappy if things went wrong. But let's be honest. Most people don't ride many miles. So the word "duty" is a rigid one used that way. There are pluses and minuses to each approach, and it's less a question of right and wrong. I still prefer to adjust bearings, but I don't own a shop.

JohnDThompson 

When Trek first started up back in the 70s, the frames and components would be shipped in separate boxes. Apparently enough dealers preferred getting partially assembled bikes, so by the 80s we were shipping bikes in a single box with most of the components already installed. When I was the assembly line inspector I would pull random bikes off the line and check that bottom brackets and headsets were properly adjusted, but hubs and pedals went out with their bearings as the component manufacturer sent them.

RobbieTunes

When the bike is hanging and a gnat lands on the rim, and it begins to move. That's smooth.