Nomu Lab Diary

CLX50 SAGAN Edition

A customer dropped off the front and rear wheels from a Roval CLX50 Peter Sagan signature model.
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Starting with the front wheel.

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The hub shell is silver,

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and the rim side marking has a sparkly finish—
it's a special edition wheel.
The lateral runout is severe, way beyond anything a manufacturer's QC would let through.
The customer could see the rim dancing up and down as it rotated.
The customer hadn't attempted any truing themselves, but somewhere some incompetent hack shop
had butchered a truing job on it. The inspection time on both wheels ended up being longer than it would take to build a wheel from scratch,
and as a result today's scheduled shipment couldn't go out (just making excuses here).

These wheels came off the customer's bike,
and looking at them, even though the customer's riding a complete bike worth over a million yen,
the wheels have precision so bad they'd never pass inspection on a basic utility bike. Interesting.

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Many of the nipples showed tool marks on the inner flange grip area,
and we replaced four that were stripped enough to warrant replacement.
I've written about this before, but some Reynolds wheel nipples have
inner flange corners that are oddly rounded,
and you shouldn't turn them except during initial assembly.
Roval nipples, whether brass or aluminum, don't strip when you grip the inner flange—
you can fully build the wheel without leaving marks.
Being able to do that is a kind of talent
(the talent to keep running a shop at this skill level,
the talent to just flip completed bikes from right to left with smooth talk).

Three of the four replaced nipples had spokes with permanent twisting deformation,
so we replaced those spokes too.

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After replacing spokes and nipples and dialing in lateral and radial runout,
here's the interim center mark.
We did an interim center check when we took the wheel in,
and actually at this point the offset amount is slightly larger.

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From that state, we brought it into center.

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Done.
Setting aside the initial state when it came in—forget about it—
I'm confident the precision now is better than when it shipped new.

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↑Replaced parts

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The bearing rotation was abnormally stiff, so we replaced it.
Before: CeramicSpeed ceramic bearings.
After: standard steel ball bearings.
The customer verified the condition before and after.
The blue seal faces inward toward the hub,
and the outer-facing side had a black seal.

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Four nipples arranged like a plus sign—the bottom one looks like it doesn't have much damage on the grip area,

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but they're all deformed enough that their square shape has turned into a diamond.

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When you just lay a spoke down normally,
the butted flat on the spoke head side sits
in the vertical direction,

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but over at the threaded end it's twisted this much.
In both images the spoke hasn't been touched—
just photographed as it sits naturally.
The middle spoke's surface is complexly dented near the threads,
so there might be damage beyond just the botched truing.

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Next, the rear wheel.

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What the hell?
The free-side spokes are twisted about 90 degrees, but separately from that
there are spokes twisted on the non-drive side too.
When I tried to straighten them with a spoke wrench on the flat section,
the spoke head that had been crushed like sliced king oyster mushroom apparently
wasn't fully seated in the hub flange
(meaning they loosened and retightened it),
so when the spoke head snapped back into the flange slot
it made a loud CRACK! and dust puffed out from the flange.
Edit: Actually, thinking about it more, it's more likely that the spoke was twisted so severely
that the crushed spoke head just slipped out of the flange slot.


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↑This is a nipple we replaced later—
they were turning it by grabbing just the very edge of the nipple.

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There was a significant amount of center offset.
The direction of drift is consistent with aging, but that's almost irrelevant.
Roval's disc brake rear wheels use 2:1 lacing with the non-drive side in tangent pattern,
so the drive side is actually looser—a rare wheel where the drive side is the weaker side.
Because of that, tightening the drive side is easy.
Yet ironically, both nipples we replaced were on the drive side.

It's like taking a wobbly wooden chair you built yourself—with four legs of different lengths—
and cutting the legs shorter and shorter until the wobbling stops,
only to end up with a chair that's now too short.
That's what the truing fiasco looked like:
tightening the drive side here and there indiscriminately.
It wasn't quite as bad as the front wheel, but there was radial runout,
and the center offset was as shown in the images above.

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We replaced two nipples and one spoke from a different hole,
then dialed in lateral and radial runout. Here's the interim center mark.
While trying not to increase the offset, it actually decreased slightly,
but honestly we've been poking around everywhere enough that an increase wouldn't be surprising.
In fact, on the front wheel the interim center showed a slight increase in offset.

I write this occasionally, but a lot of the procedure is like
solving a Rubik's cube that a monkey scrambled.

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Got it centered.

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Fixed.

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Blue tape marks where we replaced nipples,

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and white tape marks where we replaced spokes.
We didn't replace the nipple at the spoke replacement location.

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The TPU tube in the tire had a slight twist and fold marks.
The customer mentioned planning to go tubeless soon,
and the tires are already Continental 5000S TR,
so if they were to continue with tubes,
this one would be fine as-is,
but we advised against reusing it as a spare.

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↑Replaced parts

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The nipple at the bottom of the image
is the one that had shallow tool marks.

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For the spoke, starting from the spoke head
on a spoke just sitting there, untouched,

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following along

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at the thread end it's twisted just over 90 degrees.
To create this kind of permanent deformation,
you'd have to twist it about 180 degrees first and then back off,
and I can't fathom why anyone would do that.

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