A customer brought in a Vent (Campagnolo wheel model) for service.
Both front and rear hubs have play in them.
Strangely enough, when I look at the wheel by itself
and push the axle with my finger there's no play,
but when I mount it on the frame and fork and tighten it with the quick release,
lateral play appears.
I said "strangely," but I actually know the cause.
Both wheels just have cartridge bearings pressed in without adjustment, so
when the bearing internals wear down, you can't take up the play with ball race adjustment.
Also, unlike cup and cone bearings with angular contact
that hold the balls at an angle,
radial bearings develop significant lateral play when it appears.
So the only solution is to replace the bearings.
When the radial bearing internals wear down,
the inner race moves left and right relative to the outer race,
and when that movement gets large enough, the wheel develops a fanning wobble.
I disassembled it and sprayed it with parts cleaner.
It's completely rusted and dead.
↑The bearing on the left in the image is new, the one on the right is the dead one.
This bearing, HB-SC013, is the OEM part,
but I didn't peel back the lip seal myself.
I don't know what they were thinking, but problematically,
the side facing inward in the hub
has no lip seal—it's open—
and while there's plenty of grease applied,
water still gets in and causes rust in most cases.
(The new bearing in the image above gets washed
because we apply a different grease with better water resistance)
↑This is the OEM bearing "HB-SC013."
HB is the part number for the front hub, and SC is the part number for Scirocco.
The rear hub is a "freehub," so it starts with FH as the part number,
but this bearing is a size used on both front and rear,
so we use this HB number bearing on the rear hub too.
On Campagnolo pre-built wheels,
Zonda and above use cup and cone bearings,
and Scirocco and below use cartridge bearings,
so Vent and Khamsin use this bearing.
↑There's a seal sticker making it hard to see, but
this bearing is sold in units of four,
so the box says 4-HB-SC013.
It seems unlikely that Campagnolo would adopt their own proprietary bearing
just for Scirocco and lower wheels,
so this should be a standard size bearing.
(Though the Ultra Torque crankset bearing
is a special order that's only 1mm thinner than the standard size...)
To conclude, this bearing is a "6001" size,
a standard bearing with an outer diameter of 28mm / inner diameter of 12mm / thickness of 8mm.
Some people think it's ridiculous that there's no lip seal on the inside,
and if I write that you could swap it for a double-sealed 6001
I'll get in trouble, so let's stick with the OEM bearing!
↑Older boxes of 4-HB-SC013
honestly had the bearing dimensions printed on them.
When it comes to bearing replacement, the rear wheel isn't too difficult,
but the front wheel is extremely annoying.
It's not a simple press-fit—
there's a groove cut into the end of the axle with a snap ring installed in it.
Like this,
you remove it,
but this is such a pain to remove and awkward that I even made a special tool for it.
The evolution of this HB-SC013
is the HB-SC113, which allows ball race adjustment in the same manner as cup and cone bearings. It's no longer press-fit, but
the hub interior still has no seal—that hasn't changed.
Because the bearing type is different, CULT conversion isn't possible.
If you're hoping for eventual CULT conversion or that silky smooth feel from broken-in bearings,
you should just buy Campagnolo wheels Zonda and above,
but there's a trap here.
The "Bullet," which is not the Bullet Ultra,
uses HB-SC013 bearings.
Campagnolo wheels, from top to bottom, have
cup and cone CULT, USB, and ball bearings,
followed below by cartridge HB-SC013.
But with Bullet, the Bullet Ultra is CULT or USB above,
and below that, Bullet skips the cup and cone ball bearings
and goes straight to HB-SC013.
So the standard Bullet can't be CULT-converted—
from that perspective alone it's below Zonda.
Also, be careful: the bearings rust easily if water gets in.
For this Vent repair, I used the OEM HB-SC013,
but for the grease, based on my experience I used something
with better water resistance than OEM
and comparable—or probably better—rotational performance.
Perhaps for balance, the G3 spoke closest to the valve hole on the non-drive side
is a thick spoke (all others are round butted).
The Bora Ultra II used to adopt this same approach,
where two of the drive-side G3 spokes were actually oversized,
but they stopped doing that at some point.
I've been meaning to write about the whole "you shouldn't mix spokes of two or more different weights
on the same flange" rule,
and when I do, I might bring this up again.
On inspection, it had plenty of minor runout,
but compared to a hub overhaul it was nothing to worry about.
Both front and rear hubs have play in them.
Strangely enough, when I look at the wheel by itself
and push the axle with my finger there's no play,
but when I mount it on the frame and fork and tighten it with the quick release,
lateral play appears.
I said "strangely," but I actually know the cause.
Both wheels just have cartridge bearings pressed in without adjustment, so
when the bearing internals wear down, you can't take up the play with ball race adjustment.
Also, unlike cup and cone bearings with angular contact
that hold the balls at an angle,
radial bearings develop significant lateral play when it appears.
So the only solution is to replace the bearings.
When the radial bearing internals wear down,
the inner race moves left and right relative to the outer race,
and when that movement gets large enough, the wheel develops a fanning wobble.
I disassembled it and sprayed it with parts cleaner.
It's completely rusted and dead.
↑The bearing on the left in the image is new, the one on the right is the dead one.
This bearing, HB-SC013, is the OEM part,
but I didn't peel back the lip seal myself.
I don't know what they were thinking, but problematically,
the side facing inward in the hub
has no lip seal—it's open—
and while there's plenty of grease applied,
water still gets in and causes rust in most cases.
(The new bearing in the image above gets washed
because we apply a different grease with better water resistance)
↑This is the OEM bearing "HB-SC013."
HB is the part number for the front hub, and SC is the part number for Scirocco.
The rear hub is a "freehub," so it starts with FH as the part number,
but this bearing is a size used on both front and rear,
so we use this HB number bearing on the rear hub too.
On Campagnolo pre-built wheels,
Zonda and above use cup and cone bearings,
and Scirocco and below use cartridge bearings,
so Vent and Khamsin use this bearing.
↑There's a seal sticker making it hard to see, but
this bearing is sold in units of four,
so the box says 4-HB-SC013.
It seems unlikely that Campagnolo would adopt their own proprietary bearing
just for Scirocco and lower wheels,
so this should be a standard size bearing.
(Though the Ultra Torque crankset bearing
is a special order that's only 1mm thinner than the standard size...)
To conclude, this bearing is a "6001" size,
a standard bearing with an outer diameter of 28mm / inner diameter of 12mm / thickness of 8mm.
Some people think it's ridiculous that there's no lip seal on the inside,
and if I write that you could swap it for a double-sealed 6001
I'll get in trouble, so let's stick with the OEM bearing!
↑Older boxes of 4-HB-SC013
honestly had the bearing dimensions printed on them.
When it comes to bearing replacement, the rear wheel isn't too difficult,
but the front wheel is extremely annoying.
It's not a simple press-fit—
there's a groove cut into the end of the axle with a snap ring installed in it.
Like this,
you remove it,
but this is such a pain to remove and awkward that I even made a special tool for it.
The evolution of this HB-SC013
is the HB-SC113, which allows ball race adjustment in the same manner as cup and cone bearings. It's no longer press-fit, but
the hub interior still has no seal—that hasn't changed.
Because the bearing type is different, CULT conversion isn't possible.
If you're hoping for eventual CULT conversion or that silky smooth feel from broken-in bearings,
you should just buy Campagnolo wheels Zonda and above,
but there's a trap here.
The "Bullet," which is not the Bullet Ultra,
uses HB-SC013 bearings.
Campagnolo wheels, from top to bottom, have
cup and cone CULT, USB, and ball bearings,
followed below by cartridge HB-SC013.
But with Bullet, the Bullet Ultra is CULT or USB above,
and below that, Bullet skips the cup and cone ball bearings
and goes straight to HB-SC013.
So the standard Bullet can't be CULT-converted—
from that perspective alone it's below Zonda.
Also, be careful: the bearings rust easily if water gets in.
For this Vent repair, I used the OEM HB-SC013,
but for the grease, based on my experience I used something
with better water resistance than OEM
and comparable—or probably better—rotational performance.
Perhaps for balance, the G3 spoke closest to the valve hole on the non-drive side
is a thick spoke (all others are round butted).
The Bora Ultra II used to adopt this same approach,
where two of the drive-side G3 spokes were actually oversized,
but they stopped doing that at some point.
I've been meaning to write about the whole "you shouldn't mix spokes of two or more different weights
on the same flange" rule,
and when I do, I might bring this up again.
On inspection, it had plenty of minor runout,
but compared to a hub overhaul it was nothing to worry about.