I received an Easton EA90TT from a customer.
A front wheel equipped with a special narrow-flange hub.
While lateral stiffness is low, the customer views it positively, saying "it rides great,"
so it might not be a problem. Without out-of-saddle climbing or attacking tight descents,
the shortcomings don't really show, making it ideal TT bike spec.
Something is sacrificed to gain something else (aerodynamic characteristics),
so in limited situations, it actually works out fine.
The spokes were bent, so
I replaced them.
These spokes are wide-section elliptical aero spokes with about 100% spoke specific gravity in straight configuration.
Unlike CX-RAY, I don't stock every length, but I do have the length needed for this front wheel repair.
It had 16 spokes with brass nipples.
I recently got nervous about 16H hole count and
assembled a front wheel with brass nipples.
ZIPP has a similar idea, but the hub ends are airfoil-shaped.
The hub axle that accepts the friction-fit ends has a notch, so
the phase of the left and right ends always synchronizes.
Next, the rear wheel.
Actually, I worked on this one first.
The customer requested a hub overhaul, so I did one.
R4 hubs use steel ball bearings, R4SL hubs use ceramic bearings,
but either way they're Enduro bearings, so contrary to the brand name,
they wear quickly and often become gritty. In particular with R4SL, whether it's "just ceramic balls in a steel-ball race"
or something else I don't know, but they frequently seize up.
With this rear hub, while the axle was gritty when hand-rotated,
it became extremely smooth when I removed the freebody.
So the damaged bearing must be on the freebody side, either one or both.
Turns out it was both, with the inner bearing particularly damaged.
Both are size 152267.
This means inner diameter 15mm, outer diameter 26mm, thickness 7mm,
which is similar to standard bearing 6902 at 15/28/7mm.
"I want to fit this onto a 15mm aluminum axle, but if I put 6902's 28mm outer diameter in the freebody,
the spline section gets too thin, so I'm a bit worried. But 6802 is 15/24/5mm which is too thin,
so something slightly smaller in outer diameter than 6902 would be ideal"—that reasoning maybe explains
why this non-standard size shows up often lately.
Besides 152267, 172287 sometimes appears, and if you have these plus
6801-3 and 6901-3, and also Mavic hub body right side 608,
Evo front hub 699, and Evo Lite front hub 689,
you've basically covered most hub bearing needs.
Inspection revealed significant centering offset and vertical runout bad enough that the rim pulsed,
but that's the result of the customer's work, so it can't be helped.
If it were another shop's work, I'd be furious.
The same customer also left an EA90SLX with me.
The new model is completely different in both rim and hub from the old model of the same name.
It has a tubeless rim, so the rim itself is closer to the old EA90RT,
and the hub is Easton's new design.
The front wheel had no hub issues, and had only a slight preliminary center offset,
but once I corrected the single runout point, the centering became perfect.
The rear wheel had the rim shifted toward the freebody side,
but with almost no runout, I dealt with it by even tightening on the non-freebody side.
The rear hub, like American Classic, has pawls on the hub body side
and ratchet teeth on the freebody side.
The freebody's outer bearing is a 619901, but
with five-digit bearings like this, the second digit doesn't relate to size.
So it's actually a 6901. It was slightly gritty, so I replaced it.
The inner bearing is an angular contact bearing
with 36° inner contact angle and 45° outer contact angle,
which is identical to the 36/45° bearing used in 1-1/8" headsets,
so it can be repaired with that.
This bearing, though not visible in the image above,
was leaking brown rust liquid inside the hub body—quite a mess.
↑ENDURO
↑ACB3645
ACB is short for Angular Contact Bearing.
I replaced it.
ACB
3645.
A front wheel equipped with a special narrow-flange hub.
While lateral stiffness is low, the customer views it positively, saying "it rides great,"
so it might not be a problem. Without out-of-saddle climbing or attacking tight descents,
the shortcomings don't really show, making it ideal TT bike spec.
Something is sacrificed to gain something else (aerodynamic characteristics),
so in limited situations, it actually works out fine.
The spokes were bent, so
I replaced them.
These spokes are wide-section elliptical aero spokes with about 100% spoke specific gravity in straight configuration.
Unlike CX-RAY, I don't stock every length, but I do have the length needed for this front wheel repair.
It had 16 spokes with brass nipples.
I recently got nervous about 16H hole count and
assembled a front wheel with brass nipples.
ZIPP has a similar idea, but the hub ends are airfoil-shaped.
The hub axle that accepts the friction-fit ends has a notch, so
the phase of the left and right ends always synchronizes.
Next, the rear wheel.
Actually, I worked on this one first.
The customer requested a hub overhaul, so I did one.
R4 hubs use steel ball bearings, R4SL hubs use ceramic bearings,
but either way they're Enduro bearings, so contrary to the brand name,
they wear quickly and often become gritty. In particular with R4SL, whether it's "just ceramic balls in a steel-ball race"
or something else I don't know, but they frequently seize up.
With this rear hub, while the axle was gritty when hand-rotated,
it became extremely smooth when I removed the freebody.
So the damaged bearing must be on the freebody side, either one or both.
Turns out it was both, with the inner bearing particularly damaged.
Both are size 152267.
This means inner diameter 15mm, outer diameter 26mm, thickness 7mm,
which is similar to standard bearing 6902 at 15/28/7mm.
"I want to fit this onto a 15mm aluminum axle, but if I put 6902's 28mm outer diameter in the freebody,
the spline section gets too thin, so I'm a bit worried. But 6802 is 15/24/5mm which is too thin,
so something slightly smaller in outer diameter than 6902 would be ideal"—that reasoning maybe explains
why this non-standard size shows up often lately.
Besides 152267, 172287 sometimes appears, and if you have these plus
6801-3 and 6901-3, and also Mavic hub body right side 608,
Evo front hub 699, and Evo Lite front hub 689,
you've basically covered most hub bearing needs.
Inspection revealed significant centering offset and vertical runout bad enough that the rim pulsed,
but that's the result of the customer's work, so it can't be helped.
The same customer also left an EA90SLX with me.
The new model is completely different in both rim and hub from the old model of the same name.
It has a tubeless rim, so the rim itself is closer to the old EA90RT,
and the hub is Easton's new design.
The front wheel had no hub issues, and had only a slight preliminary center offset,
but once I corrected the single runout point, the centering became perfect.
The rear wheel had the rim shifted toward the freebody side,
but with almost no runout, I dealt with it by even tightening on the non-freebody side.
The rear hub, like American Classic, has pawls on the hub body side
and ratchet teeth on the freebody side.
The freebody's outer bearing is a 619901, but
with five-digit bearings like this, the second digit doesn't relate to size.
So it's actually a 6901. It was slightly gritty, so I replaced it.
The inner bearing is an angular contact bearing
with 36° inner contact angle and 45° outer contact angle,
which is identical to the 36/45° bearing used in 1-1/8" headsets,
so it can be repaired with that.
This bearing, though not visible in the image above,
was leaking brown rust liquid inside the hub body—quite a mess.
↑ENDURO
↑ACB3645
ACB is short for Angular Contact Bearing.
I replaced it.
ACB
3645.