Campy 10 Bearing Adjustment

[Appkiller]

Greetings!

Repacked my Daytona hubs late last fall. 400 miles of riding later, the rear hub felt a little
"crunchy". The front was/is still silky smooth. I disassembled the rear hub and found the grease to
be clean but a little sparse (thought I had packed it in pretty good).

I pumped a bunch of grease in per other threads' suggestion (worst thing that can happen is that it
will leak out) and reassembled. The rear bearing, adjusted in a fashion pretty much identical to the
front, spins like consumer grade, not silky like the front.

For those of you who repack these hubs every day: how do you adjust the bearings? I tighten a fair
amount and then iterate through loosen/check play 'til I can generate a tiny bit of play. Then
tighten just a bit and check that there is no play in the axle and tighten the lock ring.

Am I doing something wrong? How tight should they be? Any suggestions?

TIA

App

 

[Qui Si Parla Ca]

pete-<< how do you adjust the bearings? I tighten a fair amount and then iterate through
loosen/check play 'til I can generate a tiny bit of play. Then tighten just a bit and check that
there is no play in the axle and

How i do it-are you sure the white-ish crud seals on the left and right are seated?

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Richard]

Out of curiosity, do you adjust the bearings while the wheel is on the bike and the QR is tight? You
can do that with these hubs, which is probably the greatest thing about them!

> For those of you who repack these hubs every day: how do you adjust the bearings? I tighten a fair
> amount and then iterate through loosen/check play 'til I can generate a tiny bit of play. Then
> tighten just a bit and check that there is no play in the axle and tighten the lock ring.

 

[Appkiller]

richard <[email protected]> wrote in message news:<Ra58a.280080$tq4.6321@sccrnsc01>...
> Out of curiosity, do you adjust the bearings while the wheel is on the bike and the QR is tight?
> You can do that with these hubs, which is probably the greatest thing about them!

Actually haven't had to adjust them except for the single repack of the bearings. But if and when I
do have to, the ability to do it on the bike will be much appreciated. The other, IMHO, related but
even greater thing about them is that the QR tightness has no effect on how you set bearing pre-load
(which should be very close to 0). No more dual nuts, no more tighten QR to find that your preload
was too much or too little. I agree, the design is quite an advance! I explained it to a buddy at
work who used to ride in the days of Campy SR and he was blown away.

App

>
>
> > For those of you who repack these hubs every day: how do you adjust the bearings? I tighten a
> > fair amount and then iterate through loosen/check play 'til I can generate a tiny bit of play.
> > Then tighten just a bit and check that there is no play in the axle and tighten the lock ring.

 

[Pete Biggs]

Appkiller wrote:
> The other, IMHO, related but even greater thing about them is that the QR tightness has no effect
> on how you set bearing pre-load (which should be very close to 0).

No, that's incorrect. QR tightness still affects the bearings with these hubs. Play will disappear
when QR is closed.

~PB

 

[Pete Biggs]

Appkiller wrote:
> I pumped a bunch of grease in per other threads' suggestion (worst thing that can happen is that
> it will leak out) and reassembled. The rear bearing, adjusted in a fashion pretty much identical
> to the front, spins like consumer grade, not silky like the front.

Maybe something wrong with seals or there may be some grit in there. The freehub seal can add more
friction to the rear than the front gets - the freehub nut doesn't need to be very tight.

I find the hubs get freer after some use (after brand new or overhaul).

> For those of you who repack these hubs every day: how do you adjust the bearings? I tighten a fair
> amount and then iterate through loosen/check play 'til I can generate a tiny bit of play. Then
> tighten just a bit and check that there is no play in the axle and tighten the lock ring.

I don't do them everyday, but have read the manual and done mine enough times to know that the above
is correct - providing you mean tighten the little screw on the ring to lock it.

> How tight should they be?

With wheel on bike with QR closed normally, I find tightening just past the point of play plus a
touch more to allow for settling in does the job.

~PB

 

[Appkiller]

If you were correct, that the QR changes the preload, then you couldn't adjust them on the bike as
the tension on the QR would make it very difficult to adjust on the bike.

The only adjustment for the bearing preload is totally isolated from the QR tension, unlike on older
hub designs where the locknuts and the cones lie on the same threads and the locknuts are the
bearing surface for the dropouts.

The other race does bear against the dropout but it also bottoms out against a flange and would not
be able to move as with the old style hubs. Are you saying that the axle actually compresses when
the QR is tightened?

Please show me where I went wrong! I reviewed the exploded diagram from the campy web site tech
pdf's and it appears to support my analysis.

App

"Pete Biggs" <pLime{remove_fruit}@biggs.tc> wrote in message
news:<[email protected]>...
> Appkiller wrote:
> > The other, IMHO, related but even greater thing about them is that the QR tightness has no
> > effect on how you set bearing pre-load (which should be very close to 0).
>
> No, that's incorrect. QR tightness still affects the bearings with these hubs. Play will disappear
> when QR is closed.
>
> ~PB

 

[Sheldon Brown]

A shy person asserted:

>>>The other, IMHO, related but even greater thing about them is that the QR tightness has no
>>>effect on how you set bearing pre-load (which should be very close to 0).

Pete Briggs explained:

>>No, that's incorrect. QR tightness still affects the bearings with these hubs. Play will
>>disappear when QR is closed.

The shy person retorted:

> If you were correct, that the QR changes the preload, then you couldn't adjust them on the bike as
> the tension on the QR would make it very difficult to adjust on the bike.
>
> The only adjustment for the bearing preload is totally isolated from the QR tension, unlike on
> older hub designs where the locknuts and the cones lie on the same threads and the locknuts are
> the bearing surface for the dropouts.
>
> The other race does bear against the dropout but it also bottoms out against a flange and would
> not be able to move as with the old style hubs. Are you saying that the axle actually compresses
> when the QR is tightened?

That is correct, the axle compresses.

See: http://sheldonbrown.com/cone-adjustment.html

When I use my special adjustment tool, the compression is applied directly to the ends of the axles,
and it is quite evident that the axle is actually compressing and shortening under the load from the
QR spindle.

Sheldon "That's How It Works" Brown +-------------------------------------------+
| Being ignorant is not so much a shame | as being unwilling to learn. | -- Benjamin Franklin |
+-------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

 

[Appkiller]

Sheldon Brown <[email protected]> wrote in message
news:<[email protected]>...
> A shy person asserted:
>
> >>>The other, IMHO, related but even greater thing about them is that the QR tightness has no
> >>>effect on how you set bearing pre-load (which should be very close to 0).
>
> Pete Briggs pontificated:
>
> >>No, that's incorrect. QR tightness still affects the bearings with these hubs. Play will
> >>disappear when QR is closed.
>
> The shy person responded:
>
> > If you were correct, that the QR changes the preload, then you couldn't adjust them on the bike
> > as the tension on the QR would make it very difficult to adjust on the bike.
> >
> > The only adjustment for the bearing preload is totally isolated from the QR tension, unlike on
> > older hub designs where the locknuts and the cones lie on the same threads and the locknuts are
> > the bearing surface for the dropouts.
> >
> > The other race does bear against the dropout but it also bottoms out against a flange and would
> > not be able to move as with the old style hubs. Are you saying that the axle actually compresses
> > when the QR is tightened?
>

An experienced wrench wrote in response to my query:

> That is correct, the axle compresses.
>
> See: http://sheldonbrown.com/cone-adjustment.html
>
> When I use my special adjustment tool, the compression is applied directly to the ends of the
> axles, and it is quite evident that the axle is actually compressing and shortening under the load
> from the QR spindle.
>
> Sheldon "That's How It Works" Brown +-------------------------------------------+
> | Being ignorant is not so much a shame | as being unwilling to learn. | -- Benjamin Franklin |
> +-------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
> 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
> http://captainbike.com http://sheldonbrown.com

to which the skeptic and Campy fan responded:

Ah, yes, but MY POINT WAS you will find that the change in bearing pre-load (pre vs post QR
tightening) on a Shimano style axle to be significantly greater, and to require much more futzing
and experience to properly adjust. I would assert that most reasonable bicyclists could adjust a
Campy 10 hub bearing without having to readjust it once it is on the bike.

and further challenged:

Get out your special adjustment tool, a campy 10 hub, a shimano 9 hub and a caliper. Disassemble the
Campy hub so that all you have is the axle, bearing cups and dropout bearing nuts. Set the preload
on the Shimano bearings properly (as if you really wanted to ride the hub). Measure the distance
between dropout contact points on the Shimano hub and the distance between bearing cups on the Campy
axle. Now place the "hubs" in a frame and pop in the QR skewers. Tighten the skewers to the same
tension and measure the distance between the dropout contact points on the Shimano hub and the
bearing cups on the Campy axle.

I predict that the compression on the bearings represented by this reduction in distance due to the
compression by the QR on the Campy bearing distance is probably on the order of 1/10 to 1/20, or
even smaller, than that of the Shimano hub.

App "Put yer money where yer pie hole is at" Killer

 

[Pete Biggs]

Appkiller wrote:
> I predict that the compression on the bearings represented by this reduction in distance due to
> the compression by the QR on the Campy bearing distance is probably on the order of 1/10 to 1/20,
> or even smaller, than that of the Shimano hub.

I bet the difference is much less than that. A new-style Chorus hub can be adjusted so there's
plenty of play when a well adjusted QR is closed just barely enough to hold -- wheel clearly
clunking when pushed & pulled -- but with no play with the lever fully closed. ...Although perhaps
this reveals that I have my skewers pretty tight, but that's besides the point: The amount of
compression is significant enough to make it worthwhile to adjust the hubs on the bike - which
happens to be easier than not with these hubs.

~PB

 

[Sheldon Brown]

The mysterious "Appkiller" predicted:

> I predict that the compression on the bearings represented by this reduction in distance due to
> the compression by the QR on the Campy bearing distance is probably on the order of 1/10 to 1/20,
> or even smaller, than that of the Shimano hub.

The linear compression of the axle is proportional to the force from the QR, the average
cross-sectional area of the axle, and inversely proportional to the elastic modulus of the material
it is made from.

Thus, for a Campagnolo axle to compress only 1/10 as much as conventional axle as our anonymous
source predicts, it would have to have a cross-sectional area 10 times as great, and it would be 10
times as heavy...if it was made of steel.

Since the elastic modulus of aluminum is only 1/3 of that of steel, an aluminum axle would need have
a cross-sectional area 30 times that of a conventional axle.

However, since aluminum has only 1/3 the specific gravity of steel, it would still be only 10 times
as heavy as the conventional axle.

I might have an unfair advantage here...I actually paid attention in my high school
physics class ;-)

Sheldon "QED" Brown +----------------------------------------------------------------+
| Anyone who cannot cope with mathematics is not fully human. | At best he is a tolerable
| subhuman who has learned to wear | shoes, bathe, and not make messes in the house. | --Robert
| A. Heinlein |
+----------------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
shipped Worldwide http://captainbike.com http://sheldonbrown.com

 

[Appkiller]

Mr. Brown:

Couldn't help a further comment: the distance between bearings is about 1/2 of the total axle and
(rendering the compression between bearing surfaces 1/2 or less than the total distance between QR
ends). Also, if you take a look at axle on a Campy hub, it is thicker and of a much larger diameter
(hmmm, perhaps by a factor of 5 or probably more?). Did you take my challenge and empirically verify
your analysis of the question at hand?

You sound like the software engineers who I serve who say, "it can't have failed, my analysis shows
the software should behave as I designed it" as I show them the blue screen of death. Sometimes
paying attention in High School means little if you don't fully understand the parameters.

Your analysis misses the points I made above and probably more, therefore, even though I once
retracted my challenge, I SLAP YOUR FACE WITH MY FRILLY GLOVE ONCE AGAIN: PROVE IT! I want pix
of the micrometers. You work in a bike shop right? You can put non-QR axle bolts on with a
torque wrench, can't you? You have access to a micrometer or other high precision measuring
device, I assume?

Course, you could continue on in your merry, dismissive fashion. But then I will have the joy of
cobbling together some fake images proving my point, forcing you to either disprove through your own
efforts or to bear the derision of your peers - beaten by a mere cycling mortal on a technical
issue. And it will haunt you for the rest of your life ;-)

App "never trust anyone over thirty" Killer, who's over thirty and suspects Sheldon is too.

Sheldon Brown <[email protected]> wrote in message
news:<[email protected]>...
> The mysterious "Appkiller" predicted:
>
> > I predict that the compression on the bearings represented by this reduction in distance due to
> > the compression by the QR on the Campy bearing distance is probably on the order of 1/10 to
> > 1/20, or even smaller, than that of the Shimano hub.
>
> The linear compression of the axle is proportional to the force from the QR, the average
> cross-sectional area of the axle, and inversely proportional to the elastic modulus of the
> material it is made from.
>
> Thus, for a Campagnolo axle to compress only 1/10 as much as conventional axle as our anonymous
> source predicts, it would have to have a cross-sectional area 10 times as great, and it would be
> 10 times as heavy...if it was made of steel.
>
> Since the elastic modulus of aluminum is only 1/3 of that of steel, an aluminum axle would need
> have a cross-sectional area 30 times that of a conventional axle.
>
> However, since aluminum has only 1/3 the specific gravity of steel, it would still be only 10
> times as heavy as the conventional axle.
>
> I might have an unfair advantage here...I actually paid attention in my high school physics
> class ;-)
>
> Sheldon "QED" Brown +----------------------------------------------------------------+
> | Anyone who cannot cope with mathematics is not fully human. | At best he is a tolerable
> | subhuman who has learned to wear | shoes, bathe, and not make messes in the house. | --Robert
> | A. Heinlein |
> +----------------------------------------------------------------+ Harris Cyclery, West Newton,
> Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
> shipped Worldwide http://captainbike.com http://sheldonbrown.com