What exactly will happen if your hubs have a little play?
12-08-17, 11:36 AM
#76
Senior Member
I just want to make sure I have all the facts cleared up so that I can leave this thread properly educated.
1. Chris King recommends a light preload on their wheel and headset bearings.
2. Campagnolo recommends a light preload on their wheel and headset bearings.
3. Shimano recommends a light preload on all their bearings.
4. A mechanical engineer explained why a light preload on bicycle wheel bearings reduces drag and extends the life of the ball and tracks via increased load bearing surface area and efficient grease distribution.
5. A mechanical engineer explained why a bicycle wheel bearing with clearance between the balls and tracks will have increased drag and a reduced life span.
5. SKF, a leading bearing manufacturer says "Preload has advantages".
6. Sealed cartridge bicycle bottom brackets come with bearings that have been preloaded by the manufacturer.
7. Racing Dan says preload is bad for bicycle wheel bearings and will prevent the wheel from rolling freely.
OK. Gotcha. Thanks for the lesson.
1. Chris King recommends a light preload on their wheel and headset bearings.
2. Campagnolo recommends a light preload on their wheel and headset bearings.
3. Shimano recommends a light preload on all their bearings.
4. A mechanical engineer explained why a light preload on bicycle wheel bearings reduces drag and extends the life of the ball and tracks via increased load bearing surface area and efficient grease distribution.
5. A mechanical engineer explained why a bicycle wheel bearing with clearance between the balls and tracks will have increased drag and a reduced life span.
5. SKF, a leading bearing manufacturer says "Preload has advantages".
6. Sealed cartridge bicycle bottom brackets come with bearings that have been preloaded by the manufacturer.
7. Racing Dan says preload is bad for bicycle wheel bearings and will prevent the wheel from rolling freely.
OK. Gotcha. Thanks for the lesson.
Adjustment of the front two piece axle hub
1. Insert 5 mm hex wrenches into both ends of axle assembly.
2. Hold left hand stationary and turn right hand counterclockwise 1/4 turn until assembly is
loose.*Pro Tip: Use a bench vice to hold one of the 5mm hex wrenches.
3. Hold hex wrenches stationary and adjust bearing preload with adjusting cone.
4. Advance adjusting cone until it just contacts bearing, then back off approximately 1/16 turn
(this allows for axle compression while under skewer clamp pressure).
5. Once preload is set, tighten axle assembly to 110 in.-lb. or 12.43Nm
6. Double check adjustment by clamping wheel into fork with quick-release. Check for play
or binding, and readjust if needed.
This is not applying preload. Its the opposite. Its applying clearance even if CC writes "Once preload is set ..."
You literally have no idea what preload is. You are just regurgitating forum folklore backed with feverish searches for titbits that seem to support your stance. By your definition every setting of the cone is in some sense "preload" even if the actual setting creates a clearance like CC instructs.
12-08-17, 11:46 AM
#77
Senior Member
Not argument - more a question, so correct me if I'm wrong. For all I know friction in a loaded bearing that is properly (optimally) preoloaded doesn't increase compared to a bearing that isn't preloaded.
That is: load of a single ball in a preloaded bearing, once a bearing is loaded, does not increase due to the bearing having preload - compared to a bearing with no preload. Preload enables better load distribution over more than one ball and smoother rolling.
That is: load of a single ball in a preloaded bearing, once a bearing is loaded, does not increase due to the bearing having preload - compared to a bearing with no preload. Preload enables better load distribution over more than one ball and smoother rolling.
"It could be argued that preload is acceptable,
provided the bearing operates in a zone that
does not exceed light preload († diagram 2,
zone between 0 and –1). In this case, however,
there is an increase in friction and frictional
heat."
This obviously mostly apply to bearing rotating at much higher rpm than a bicycle wheel, but none the less, preload equals more friction that a bearing adjusted to have a clearance.
12-08-17, 12:02 PM
#78
Calamari Marionette Ph.D
You know what they call the bolt used for threadless head set bearing adjustment? A preload bolt.
Scoreboard:
Every one else in the world, 1
Racing Dan, 0
I've written what I have because I've experienced it first hand. I "regurgitate" what mechanical engineers say because their education qualifies their statements. And since they agree with my real world experience, they support my position. Not yours.
You want links?
Bicycle wheel bearings, as most, require a slight preload so that more than one ball under the cone (inner race) will support its load. With proper preload, slight drag should be perceptible. Preload drag is small compared to drag caused by wheel loads, neither of which are significant regardless of adjustment. In contrast bearing life is affected by proper adjustment. Adjusting ball bearings to spin freely unloaded does not reduce operating friction because a bearing with proper preload has lower drag when loaded than one with clearance. For high quality bearings, preload should be just enough to cause light drag when rotating the axle between thumb and forefinger
Jobst Brandt (January 14, 1935 – May 5, 2015) was an American mechanical engineer, inventor, bicycle enthusiast, educator, and author.
.........he found employment at Porsche.[4] His subsequent employers included Hewlett Packard, SLAC National Accelerator Laboratory, and Avocet, a bicycle accessories brand.[5] At Avocet, he was involved in the development of a cyclocomputer (patent 6,134,508), touring shoes (patent 4,547,983), and a high-performance bicycle tire, and published The Bicycle Wheel, a unique treatise on wheelbuilding which became a best-seller
.........he found employment at Porsche.[4] His subsequent employers included Hewlett Packard, SLAC National Accelerator Laboratory, and Avocet, a bicycle accessories brand.[5] At Avocet, he was involved in the development of a cyclocomputer (patent 6,134,508), touring shoes (patent 4,547,983), and a high-performance bicycle tire, and published The Bicycle Wheel, a unique treatise on wheelbuilding which became a best-seller
So yeah, qualified.
https://en.wikipedia.org/wiki/Jobst_Brandt
https://www.sheldonbrown.com/brandt/...djustment.html
12-08-17, 12:21 PM
#79
Senior Member
Yes i an reading it and Im reading your comments. Again and again you quote small fragment in a fashion that shows you have no clue what you are talking about. I just explained why you are wrong to conclude CC is recommending preloading the bearings, but of course you completely disregard it and make a new misguided quote, showing you have no clue or are simply obtuse. As I said to the other guy. Go debate SKF. I principally said what I came for in #48. You can believe in who ever you want.
12-08-17, 12:24 PM
#80
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12-08-17, 12:33 PM
#81
Calamari Marionette Ph.D
Yes i an reading it and Im reading your comments. Again and again you quote small fragment in a fashion that shows you have no clue what you are talking about. I just explained why you are wrong to conclude CC is recommending preloading the bearings, but of course you completely disregard it and make a new misguided quote, showing you have no clue or are simply obtuse. As I said to the other guy. Go debate SKF. I principally said what I came for in #48. You can believe in who ever you want.
12-08-17, 12:44 PM
#83
Senior Member
No I did not. There were no more bullets than the 6 I quoted or any other qualifier.
Last edited by Racing Dan; 12-08-17 at 12:48 PM.
12-08-17, 12:44 PM
#84
Calamari Marionette Ph.D
I can't do that because they agree with me.
A brand new SKF bottom bracket will have zero play. No clearance between the balls and races. In order to capture the balls between the races, a force (pressure) must be applied to them. That force may be as little as .0000000000000000001 Lb. But it is a force nonetheless. The bearing industry calls that force preload.
SKF preloads the bearings in the bottom brackets that they manufacture.
A brand new SKF bottom bracket will have zero play. No clearance between the balls and races. In order to capture the balls between the races, a force (pressure) must be applied to them. That force may be as little as .0000000000000000001 Lb. But it is a force nonetheless. The bearing industry calls that force preload.
SKF preloads the bearings in the bottom brackets that they manufacture.
12-08-17, 12:48 PM
#85
Calamari Marionette Ph.D
Although small, axle compression on QR hubs is large enough to alter bearing clearance and should be considered when adjusting bearings. Bearings should be adjusted just loose enough so that closing the QR leaves the bearing with a slight preload. Excessive preload from QR closure is the cause of most wheel-bearing failures not caused by water intrusion. Clearance, in contrast, can be felt as disconcerting rattle when encountering road roughness
12-08-17, 12:50 PM
#86
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SKF site does provide very good info. However, they manufacture bearings for all sorts of uses, loads and various types of bearings. From what I've learned, ball bearings should have an optimal amount of preload (no clearance/play) when in use - under load. Some machines/constructions would provide bearing preload, even if unmounted (or at least unloaded) bearings do have some clearance (play). For a bicycle cup and cone bearing, loading the wheel would not eliminate play, so an appropriate preload must be set (manually).
My point being that SKF info doesn't contradict quoted Brandt's text on preload. At least in my understanding.
My point being that SKF info doesn't contradict quoted Brandt's text on preload. At least in my understanding.
12-08-17, 12:54 PM
#87
Senior Member
12-08-17, 12:54 PM
#88
Senior Member
I can't do that because they agree with me.
A brand new SKF bottom bracket will have zero play. No clearance between the balls and races. In order to capture the balls between the races, a force (pressure) must be applied to them. That force may be as little as .0000000000000000001 Lb. But it is a force nonetheless. The bearing industry calls that force preload.
SKF preloads the bearings in the bottom brackets that they manufacture.
A brand new SKF bottom bracket will have zero play. No clearance between the balls and races. In order to capture the balls between the races, a force (pressure) must be applied to them. That force may be as little as .0000000000000000001 Lb. But it is a force nonetheless. The bearing industry calls that force preload.
SKF preloads the bearings in the bottom brackets that they manufacture.
Except SKF states in they own manual:
"Although all bearing types can run with some
preload, SKF recommends a positive operating
clearance. This is particularly important for
roller bearings such as cylindrical roller, needle
roller, spherical roller and CARB toroidal roller
bearings."
12-08-17, 12:57 PM
#89
Senior Member
12-08-17, 01:00 PM
#90
Enjoying the ride
Question
I'm seeing the term "compression" when describing what happens to a QR axle when the skewer is clamped. Would a more accurate term be "flexed" or "flexion"?
Regards
Rod
I'm seeing the term "compression" when describing what happens to a QR axle when the skewer is clamped. Would a more accurate term be "flexed" or "flexion"?
Regards
Rod
Last edited by rodteague; 12-08-17 at 01:27 PM.
12-08-17, 01:03 PM
#91
Calamari Marionette Ph.D
Except SKF states in they own manual:
"Although all bearing types can run with some
preload, SKF recommends a positive operating
clearance. This is particularly important for
roller bearings such as cylindrical roller, needle
roller, spherical roller and CARB toroidal roller
bearings."
"Although all bearing types can run with some
preload, SKF recommends a positive operating
clearance. This is particularly important for
roller bearings such as cylindrical roller, needle
roller, spherical roller and CARB toroidal roller
bearings."
BTW, their bottom brackets use balls, not the other types that you are referring to. And yes, it matters.
12-08-17, 01:05 PM
#92
Senior Member
12-08-17, 01:11 PM
#94
Calamari Marionette Ph.D
I've quoted (and provided links) for a (over qualified) mechanical engineer, who has written a best selling book about bicycle wheels, and held bicycle related patents. I've quoted (and provided links) for the major and premier bicycle hub manufacturers. They all agree, light preload is better than play. Even your holy grail of support sells their own product preloaded.
12-08-17, 01:21 PM
#95
Calamari Marionette Ph.D
I never claimed that was from CC. I was just providing what is common knowledge, written better than I can.
But if you really want Chris King's opinion on preload, here it is, from their instruction manual.
You may notice that the use the word "Preload" frequently. You may notice that they emphasize the importance of not allowing the bearings to become loose (clearance)
And here is the link, so you don't accuse me of bait and switch
https://chrisking.com/files/public/c...l_11-14_v3.pdf
Adjust the preload on the bearings directly after building the
wheel
Spoke tension pulling out on the flanges can slightly loosen the preload adjustment on the
bearings. The hub(s) come pre-adjusted from the factory anticipating both spoke tension and
skewer compression. However, because of variations in wheel-building practices, a minor
adjustment should always be performed upon completion of the wheel build. Please see the
appropriate “adjustment” section and check the hub before using.
Chris King hubs feature adjustable bearing preload
The bearings should be kept in proper adjustment for optimum product performance. Do not
allow the adjustment to become loose, as this may cause a loss of performance that could
lead to damage to the hubs.
R
wheel
Spoke tension pulling out on the flanges can slightly loosen the preload adjustment on the
bearings. The hub(s) come pre-adjusted from the factory anticipating both spoke tension and
skewer compression. However, because of variations in wheel-building practices, a minor
adjustment should always be performed upon completion of the wheel build. Please see the
appropriate “adjustment” section and check the hub before using.
Chris King hubs feature adjustable bearing preload
The bearings should be kept in proper adjustment for optimum product performance. Do not
allow the adjustment to become loose, as this may cause a loss of performance that could
lead to damage to the hubs.
R
12-08-17, 01:56 PM
#96
Senior Member
No of course you didnt state where you got it. You tried to pull a fast one, to make me look like a liar. Hence my reaction 
You are still under the impression that CK instructs to set a negative clearance even if they state no such thing. They state "Do not allow the adjustment to become loose". That is not the same thing. In the other segment they stated "4. Advance adjusting cone until it just contacts bearing, then back off approximately 1/16 turn (this allows for axle compression while under skewer clamp pressure)." No where do they instruct setting an actual preload or a setting that will result in a bearing that is actually preloaded once mounted. I already explained this twice before. To my knowledge Ck hubs er not even cup and cone anyway.
Imo this is getting nowhere. Do what you feel is best. I already achieved what I came for. That is challenging the mindless "you must always use preload" dogma that seem to rule the bike forums.
You are still under the impression that CK instructs to set a negative clearance even if they state no such thing. They state "Do not allow the adjustment to become loose". That is not the same thing. In the other segment they stated "4. Advance adjusting cone until it just contacts bearing, then back off approximately 1/16 turn (this allows for axle compression while under skewer clamp pressure)." No where do they instruct setting an actual preload or a setting that will result in a bearing that is actually preloaded once mounted. I already explained this twice before. To my knowledge Ck hubs er not even cup and cone anyway.
Imo this is getting nowhere. Do what you feel is best. I already achieved what I came for. That is challenging the mindless "you must always use preload" dogma that seem to rule the bike forums.
12-08-17, 02:24 PM
#97
Calamari Marionette Ph.D
12-08-17, 02:30 PM
#98
Senior Member
"Preload = contact"
Im sorry dude. At this point you are a joke. Two days in and you still demonstrate over and over that you still have no clue what preload actually means.
Bye sock puppet!
Im sorry dude. At this point you are a joke. Two days in and you still demonstrate over and over that you still have no clue what preload actually means.
Bye sock puppet!
12-08-17, 02:36 PM
#99
Senior Member
There's a fine line between too much and too little play. Too little play meaning the bearings grind. Both aren't good for the hubs. The higher quality the hubs are generally the easier it is to get them adjusted properly. Too much play will wear-out bearings prematurely as will bearings that are too tight and grind.
I generally adjust the bearings so that there is just a little play before the wheel is mounted to the fork or frame. What I mean by a "little play" is just the tiniest bit of play in the hub using the fingers as a gauge. Once the hubs are tightened onto the fork and frame, that alone will squeeze them a tad tighter. If done right there will be no play and no grinding. This takes patience and experience to get right. I then spin the wheel very lightly and let go. If the wheel spins to a gradual stop and doesn't slow down and then stop immediately I know I've got them adjusted correctly. If the wheel spins and stops and/or rocks back the hubs are too tight. I then remove the wheel, re-adjust the hubs a little looser and try again. For me this is done more easily with the tire and tube removed. The added weight of the tire and tube makes it more difficult, for me, to know if the wheel came to a gradual stop on its own rather than the weight doing it.
With bikes that I have owned for years it's easier than newer bikes that I don't have experience with. One bike in particular is a difficult bike to adjust. I don't know why but it is. The hubs on that bike are about a mid-grade set. My high-end hubs are always much easier to adjust properly.
-
I generally adjust the bearings so that there is just a little play before the wheel is mounted to the fork or frame. What I mean by a "little play" is just the tiniest bit of play in the hub using the fingers as a gauge. Once the hubs are tightened onto the fork and frame, that alone will squeeze them a tad tighter. If done right there will be no play and no grinding. This takes patience and experience to get right. I then spin the wheel very lightly and let go. If the wheel spins to a gradual stop and doesn't slow down and then stop immediately I know I've got them adjusted correctly. If the wheel spins and stops and/or rocks back the hubs are too tight. I then remove the wheel, re-adjust the hubs a little looser and try again. For me this is done more easily with the tire and tube removed. The added weight of the tire and tube makes it more difficult, for me, to know if the wheel came to a gradual stop on its own rather than the weight doing it.
With bikes that I have owned for years it's easier than newer bikes that I don't have experience with. One bike in particular is a difficult bike to adjust. I don't know why but it is. The hubs on that bike are about a mid-grade set. My high-end hubs are always much easier to adjust properly.
-
Last edited by drlogik; 12-08-17 at 02:43 PM.
12-08-17, 03:22 PM
#100
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