You put in as many will fit in and then remove one, so 8 sounds correct here.

 

^^^ This is correct ^^^

 

9 bearings of 1/4" diameter for the rear hub. It's not uncommon to find eight bearings though. -1 will reduce friction at the cost of bearing load and subsequently bearing life. For your application I don't see an issue either way. If it had eight to begin with, and that's all you have per side, then save yourself a trip and $ for adding one more.

 

One reason for the extra space is to prevent/minimize counter-rotational friction of the balls.
TBH, the thread title had me coming here to make a snarky comment...

 

Sheldon Brown's site mentions 9 bearings of 1/4" diameter for rear hub.

9 bearings of 1/4" diameter for the rear hub.

Any Shimano hub from the 90's I've seen has 2 bearings.
The nine 1/4" spherical things are balls in a specific type of bearing (angular contact cup-and-cone ball bearing).

 

This correct, they are 'balls'. Thank you for the clarification.

 

You put in as many will fit in and then remove one, so 8 sounds correct here.

^^^ This is correct ^^^

Nope. 9 is what Shimano used and hence what I would consider "correct".

 

Nope. 9 is what Shimano used and hence what I would consider "correct".

I am pretty sure that the hubs are not Shimano. The reason is that Shimano likes to put their name in everything. There is no label or stamped metal identifiers on the hub.

I tend to agree with our respected member "Jond63".

Thanks,

Vic

 

I am still not sure about balls rubbing together in a cup and cone setup. In a sealed bearing there is a cage that ensures the space around each ball. In cup and cone it is not clear.

There's always rubbing and sliding friction to some degree in a ball or roller bearing, cage or not.

 

Thank you very much to everyone who has replied.

I think those who post videos on YouTube need to make sure that they mention the fact that you may not be able to recover all balls so they must mention what are pros and cons of full race and full race - one.

I tried it both ways, then I put in 8 balls. Because when comparing the sealed or caged bearings. There is a gap between the balls because of cage.

So it stands to reason that thermal expansion of balls or expansion of balls due to extra weight of the cyclist may cause problems since all balls will rub against each other.

This leaves us with the question of why companies do not use sealed bearings or caged bearings. This may be due to the weight of the rider, it is supported completely with the lower half of the balls in a cup race.

However, I am of the opinion that all cup and cone bearings must be dropped from all vertical load bearing elements in a bike and if need be they must be replace with materials which can withstand greater loading.

I am not happy with this holding the wet finger in the air estimation. I thought mechanical engineering was a fully developed science. So my thumb down for mechanical engineers and ABEC.

I am so happy I did not study half backed Mechanical Engineering.

Best regards,

Vic

 

So it stands to reason that thermal expansion of balls or expansion of balls due to extra weight of the cyclist may cause problems since all balls will rub against each other.

Thermal expansion? Weight? Neither of this matters.
Balls in a bearing will always rub against something. If they are caged, they will rub against the cage. If they are loose, they will eventually rub against another ball - regardless of how much space there is in avegerage. No two balls in a bearing are exactly the same and some will rotate faster than others. Also balls can slipp. That's why bearings with a small number of balls need cages. They fall apart quickly without, even if you perfectly align the balls during assembly.

This leaves us with the question of why companies do not use sealed bearings or caged bearings. This may be due to the weight of the rider, it is supported completely with the lower half of the balls in a cup race.

Pretty much all bearings on bikes these days are sealed, even on cheapish bikes. Most bike bearings these days have a cage and are radial bearings often called "cartridge" bearings in the bike industry. Is this type what you mean by "sealed bearings"? Shimano style cup-and-cone bearings are realtively rare.

The only benefit of cages over fully filled bearings is the price. That's why very cheap cup-and-cone hubs actually do have a cage.
The friction problem that you picture does not exist, respectively is in the favor of non-cage bearings.

However, I am of the opinion that all cup and cone bearings must be dropped from all vertical load bearing elements in a bike and if need be they must be replace with materials which can withstand greater loading.

I am not happy with this holding the wet finger in the air estimation. I thought mechanical engineering was a fully developed science. So my thumb down for mechanical engineers and ABEC.

Your opinion is based on a 90's Shimano Exage 200 GS hub? Or am I picturing the wrong Trek 800?
You're saying that Shimano engineers, who still appear to swear by cup-and-cone hubs, get your thumb down? You should buy a Sram hub with sealed caged radial bearings. Let us know your experiences with that 😂
What's the role of ABEC in Shimano hubs?

I am so happy I did not study half baked Mechanical Engineering.

So what is your fully-toast degree in?
My guess is physics

 

It is "half-baked"! Sorry for the typos.

 

ABEC sets the standards of ball bearings.

I truly believe that Mechanical Engineering is a half-baked science.

When you say that expansion and weight do not matter. You are partly right. All expansion is due to Kinetic energy of the molecules. So heating, friction, or weight do no matter... in an absolute sense, all the expansion is the result of Average Kinetic Energy of the molecules of balls and bearings. It does not matter how this increase is achieved.

Shimano or any other company engineers are just that: Half-educated people!

Bearing is not a new "invention" however they might have been able to calculate it to pretty well, if given the properties of material, like hardness, ductility, thermal expansion coefficients, and resistance to corrosiveness.

Sometimes, I wonder if it is just the marketing people who sell people and draw distinctions where there are none. As an example, grease.

Vic

 

ABEC sets the standards of ball bearings.

Again, what has ABEC to do with Shimano hubs?

I truly believe that Mechanical Engineering is a half-baked science.
[...]
Shimano or any other company engineers are just that: Half-educated people!

What constitutes a fully educated person, in your experience?

When you say that expansion and weight do not matter. You are partly right. All expansion is due to Kinetic energy of the molecules. So heating, friction, or weight do no matter... in an absolute sense, all the expansion is the result of Average Kinetic Energy of the molecules of balls and bearings. It does not matter how this increase is achieved.

I'm not following the context here...
You certainly sound like a physicist who believes they are the smartest of all people and have the ultimate wisdom.

What constitutes a fully educated person, in your experience?
I'm also curious what's a fully baked science in your view? Physics? With those folks who come up with questionable things like dark matter and dark energy to save their even more questionable models and views of the world? We clearly see physicist having run into a dead-end with their theories. No progress has been made, and dark matter will never be identified. It's just a fudge factor in a naive human model.

Bearing is not a new "invention" however they might have been able to calculate it to pretty well, if given the properties of material, like hardness, ductility, thermal expansion coefficients, and resistance to corrosiveness.

Again, I'm not following the context here and what you're trying to say.

Sometimes, I wonder if it is just the marketing people who sell people and draw distinctions where there are none. As an example, grease.

Still lacking the context.

 

Put in 9 balls per side and thermal expansion be damned.

 

I like this simple non-equivocal reply! Thank you very much for a straight forward simple answer.

Warm Regards,

Vic

 

First of all, can you teach me how you reply to each statement that I want to comment on.

I trust in your smartness to figure this out on your own and I don't want to take away that wonderful moment from you ;-)

 

Thank you for straight-forward refusal to help.

Regards,

Vic

 

Thank you for straight-forward refusal to help.

That's honestly not what I did.

Why do you insist on exposing yourself?

... as what?

remedial education.

I can tolerate arrogance to a large degree, even physicists' arrogance, not to say hubris, but that's a little too far in into the offensive realm. Calling a whole entirety of professionals "half-educated" was already a little too much and rather dumb. I'm out. Good luck with your bike and science.

 

That's honestly not what I did.

Calling a whole entirety of professionals "half-educated" was already a little too much and rather dumb. I'm out.

Well, if a person is not able to tell the difference between "Mechanical Engineering" and it's practitioners: It is a sad commentary on our education system.

What makes it as alarming is that I drew a distinction between "Mechanics" and "Mechanical Engineering" one a developed science "Landau and Lifshitz series" and other a half-baked area.

Thank you for your help.

Vic

 

Well, if a person is not able to tell the difference between "Mechanical Engineering" and it's practitioners: It is a sad commentary on our education system.

Respect for this much self-reflection:

I thought mechanical engineering was a fully developed science. So my thumb down for mechanical engineers and ABEC. [...] half backed Mechanical Engineering.

I truly believe that Mechanical Engineering is a half-baked science. [...] Shimano or any other company engineers are just that: Half-educated people!

But why do you blame the education system?

What makes it as alarming is that I drew a distinction between "Mechanics" and "Mechanical Engineering"

This is actually the first time you mention "Mechanics". Your glorification of physics was rather implied between the lines.

"Landau and Lifshitz series"

=> VictorE60 is a physics student. q.e.d.
Second year?

a half-baked area.

This is getting boring. I don't know if I'm the only one who doesn't understand what your actual problems with bearings is.

 

Live on the edge man

Thanks for a straightforward suggestion.

I am trying to learn about bicycles in my old age. I find it better to keep my mind sharp and it appears to be better than sitting on the couch all day and getting yelled at by my wife

So I am going through all the crap that we have accumulated over the years.

I was taken in by someone servicing the front hub and dynamo of a Strumy Archer bike which was 60+ years old. I am especially, amazed by the quality of work and damn impressed by the oiling ports in the hub.

Thank you once again.

Vic

 

Just popped open the 756 hub, running on 17 balls on each side, on cones. Its at least 7 seasons old and was great.

 

Thank you!

 

Leftheaded is a nuisance.