Ball Bearings: "Chrome" or "Chrome Steel" or what?
02-20-20, 03:40 PM
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02-21-20, 07:47 AM
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Well said. Over half of industrial electrical motor failures have the same failure modes as bicycles, not the bearings, the most common being inappropriate re-lubrication intervals and over filling grease cavities. I was a maintenance manager in mining, where we had a 10,000 horsepower motor that we had to notify the largest nuclear power plant in the US before we started her up.
Last edited by easyupbug; 02-21-20 at 07:47 AM. Reason: edit
02-21-20, 08:47 AM
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Well said. Over half of industrial electrical motor failures have the same failure modes as bicycles, not the bearings, the most common being inappropriate re-lubrication intervals and over filling grease cavities. I was a maintenance manager in mining, where we had a 10,000 horsepower motor that we had to notify the largest nuclear power plant in the US before we started her up.
03-04-20, 10:49 PM
#29
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I actually purchased 80 ball bearings of a few different sizes at the local co-op.
The small bottles from which I dispensed the bearings were worn/dirty and the diameters were written in marker on the bottles. Some other bottles of bearings were brought out though, and I was able to read "Carbon Steel" and a grade of like 200 or 250! So, those were some low grade ball bearings there compared to what I read online were preferred (what, grade 20 or something?)
For the record, I'm still unclear on how the word "chrome" really factors in here, but I am going to assume that "chrome steel" is a type of steel alloy.
FYI, the lead guy at the co-op did say he had seen some used ball bearings that appeared to have had a coating coming off. Chrome plating?
The small bottles from which I dispensed the bearings were worn/dirty and the diameters were written in marker on the bottles. Some other bottles of bearings were brought out though, and I was able to read "Carbon Steel" and a grade of like 200 or 250! So, those were some low grade ball bearings there compared to what I read online were preferred (what, grade 20 or something?)
For the record, I'm still unclear on how the word "chrome" really factors in here, but I am going to assume that "chrome steel" is a type of steel alloy.
FYI, the lead guy at the co-op did say he had seen some used ball bearings that appeared to have had a coating coming off. Chrome plating?
03-04-20, 11:39 PM
#30
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Probably not chrome plated -- probably the balls were corroded and of inconsistent appearance when rotated under light.
I know that using grade 25 ball bearings for bicycle applications may seem like overkill, but there is, in my opinion, a noticeable difference in the smoothness of rotation between a Record hub and, for example, a Normandy Sport -- or even a Normandy Luxe Competition. Every Mavic hub I've ever held was super smooth also, smoothest cartridge bearing hub. Of course, it's not just the balls because putting grade 25 balls in a Normandy Sport won't make it spin like a Record, or even a Nuovo Tipo, I've tried. So, maybe a Record hub with grade 300 balls would spin as smooth.
As for grease fill in bicycle applications, I found this posting by Ric Hjertberg interesting.
I know that using grade 25 ball bearings for bicycle applications may seem like overkill, but there is, in my opinion, a noticeable difference in the smoothness of rotation between a Record hub and, for example, a Normandy Sport -- or even a Normandy Luxe Competition. Every Mavic hub I've ever held was super smooth also, smoothest cartridge bearing hub. Of course, it's not just the balls because putting grade 25 balls in a Normandy Sport won't make it spin like a Record, or even a Nuovo Tipo, I've tried. So, maybe a Record hub with grade 300 balls would spin as smooth.
As for grease fill in bicycle applications, I found this posting by Ric Hjertberg interesting.
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04-02-20, 12:20 AM
#31
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The steel for bearings is usually 52100, which has 1% carbon, about 1.5% Chromium, and a lesser amount of several other metals. Calling it chrome steel is common, if not very informative.
04-02-20, 12:32 AM
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You'll notice a real difference climbing. (Your wallet will be a lot lighter.)
04-02-20, 05:09 AM
#33
Industry guy
As I recall, the # grade of the bearing is not only the precision of size and an indicator of material quality,
but the the consistency of size relative to the other bearings as well. All the balls are within a given tolerance
of size to the others.
The lower the grade number, the higher/closer the tolerances.
That is why there are more expensive, and IMO, worthwhile for precision replacements.
All things being equal, a grade 25 bearing (Campagnolo quality) in a precision setting will likely be smoother, and
have a longer life than a grade 300 matched set up.
Replacing a grade 25 bearing with a grade 300 version will likely cause pitting of the cone and bearing to be accelerated.
Replacing a 300 grade bearing with a grade 25 bearing in a non precision setting( soft, non ground cone and cup) will not offer
any appreciable benefit, although it will work well. It will not stave off the wear inherent in a non precision set up.
Wear is a function of the least precise part and ground surfaces are much more precise.
Low end cones(softer, non ground, chromed) and low end bearings(grade 300 ) will be common on bicycles, but are more
likely to pit the cones and break down the bearings- even if there were properly adjusted.
It is not that "Campagnolo quality " cones and bearings cannot pit, but would be generally less likely to if properly
assembled, adjusted and with occasional service.
Impurities in the grease from use(dust, dirt) or metal particles from the manufacturing process that were not removed
before assembly are the bane of longevity.
Check the grease out of a low end hub, headset or crank, especially if they use retainer type bearings, after years of use.
You will likely find there is some metal particles from the break down of the bearing and or cone.
The grease will have a metallic color and will feel a bit "rough" when you roll it around on your fingers.
The surfaces of the bearing will also bear a different finish than a precision ground, better steel grade set up.
rusty
but the the consistency of size relative to the other bearings as well. All the balls are within a given tolerance
of size to the others.
The lower the grade number, the higher/closer the tolerances.
That is why there are more expensive, and IMO, worthwhile for precision replacements.
All things being equal, a grade 25 bearing (Campagnolo quality) in a precision setting will likely be smoother, and
have a longer life than a grade 300 matched set up.
Replacing a grade 25 bearing with a grade 300 version will likely cause pitting of the cone and bearing to be accelerated.
Replacing a 300 grade bearing with a grade 25 bearing in a non precision setting( soft, non ground cone and cup) will not offer
any appreciable benefit, although it will work well. It will not stave off the wear inherent in a non precision set up.
Wear is a function of the least precise part and ground surfaces are much more precise.
Low end cones(softer, non ground, chromed) and low end bearings(grade 300 ) will be common on bicycles, but are more
likely to pit the cones and break down the bearings- even if there were properly adjusted.
It is not that "Campagnolo quality " cones and bearings cannot pit, but would be generally less likely to if properly
assembled, adjusted and with occasional service.
Impurities in the grease from use(dust, dirt) or metal particles from the manufacturing process that were not removed
before assembly are the bane of longevity.
Check the grease out of a low end hub, headset or crank, especially if they use retainer type bearings, after years of use.
You will likely find there is some metal particles from the break down of the bearing and or cone.
The grease will have a metallic color and will feel a bit "rough" when you roll it around on your fingers.
The surfaces of the bearing will also bear a different finish than a precision ground, better steel grade set up.
rusty
