I received a front wheel from a Cosmic Pro Carbon (Fulcrum wheel) from a customer.
The image above is after the work.
I'll explain the meaning of the marking tape later.
It got hit in an accident, so
the customer asked me to inspect it.
This isn't directly related to that incident, but
it's something you see dating back to the era of lugged steel frames—
even when the front of the front wheel takes the hit directly in a head-on collision,
the wheel often stays completely intact while the frame or fork
bends. When a frame bends, wrinkles appear on the top tube and down tube near the head lugs (diagram A above).
When a fork bends, it deforms backward just below the crown (B above).
In either case, you get wrinkles accompanied by paint cracks.
A and B don't usually happen at the same time.
It's like when you make two (or more) cuts in a piece of paper
and then tear it apart—
only the weakest (most tearable) cut expands
and you can't tear two or more cuts simultaneously.
The same principle applies here: in a head-on collision, only the weakest point gets crushed.
For commuter bikes (mamachari), B tends to happen; for sports bikes, A is more common.
On a separate note, Bridgestone's ancient RADAC (Rayac) lugged aluminum frames
often develop wrinkles at location A over time, even without accident damage.
I have photos from a customer of an accident bike, and
the Cannondale frame was crushed right at location A—not just wrinkled but completely destroyed.
From what I could see in the photos, the fork seemed okay,
but I wouldn't recommend using it.
If there are no cracks around the lower headset cup, it might be usable,
but I can't say that with certainty.
Now, about the wheel:
No centering runout, and
just one spoke that was starting to turn sideways
and slight lateral runout in two places.
The bearings weren't perfect, but
I didn't replace them.
The left side quick-release end cap on the hub, which should normally come right off by hand,
had white rust buildup and was stuck fast. I managed to get it off,
wiped away the rust with oil, gave it a light spray of silicone lubricant, and reinstalled it.
I also applied grease to the part directly below the bearing on the hub shaft.
On a tangent here—Wako's spray can
says "silicone lubricant" on the label, not "silicon lubricant."
That's what you'd expect from a chemical company. They don't confuse silicon and silicone.
Though what I used this time wasn't Wako's product.
↑The rim in this image is rotating.
I've trued out the lateral runout to the point where it's essentially gone.
At the outermost edge, the gauge contacts at just one spot.
The bead hook is bulging slightly outward.
When you set it so the gap between rim and gauge
looks like this at nearly every phase,
there's still one phase where the gauge touches.
Also, in the image above, you can see fibers
poking through the gaps in the carbon weave.
↑Brake zone at an unaffected phase
↑Brake zone at the phase where it's slightly bulging
The carbon pattern looks rough and bumpy here.
The bead hook on the opposite side of this is fine.
Only on this side.
I marked this phase on the rim with blue tape at the beginning.
There are no traces of brake shoe melt or adhesion,
and since there are no similar spots elsewhere,
this is more likely caused by the accident impact rather than brake heat warping.
Most of the impact was probably transmitted through the frame, but
it's possible the rim took a direct hit at this spot
during the collision rather than hitting the ground.
For the wheel, I think it'll be fine to use as long as you adjust
the brake shoe contact point slightly toward the inner edge.
I placed the marking tape here.
Anyway, I may have done this customer a disservice.
An excerpt from their letter, exactly as written:
"Over the past 15 years I've been a Mavic believer and experienced several complete wheelsets, but
compared to any of them with the Nomulab No. 7, I noticed the Mavic wheels were mediocre as rotating objects."
...Damn, I'm sorry about that.
The image above is after the work.
I'll explain the meaning of the marking tape later.
It got hit in an accident, so
the customer asked me to inspect it.
This isn't directly related to that incident, but
it's something you see dating back to the era of lugged steel frames—
even when the front of the front wheel takes the hit directly in a head-on collision,
the wheel often stays completely intact while the frame or fork
bends. When a frame bends, wrinkles appear on the top tube and down tube near the head lugs (diagram A above).
When a fork bends, it deforms backward just below the crown (B above).
In either case, you get wrinkles accompanied by paint cracks.
A and B don't usually happen at the same time.
It's like when you make two (or more) cuts in a piece of paper
and then tear it apart—
only the weakest (most tearable) cut expands
and you can't tear two or more cuts simultaneously.
The same principle applies here: in a head-on collision, only the weakest point gets crushed.
For commuter bikes (mamachari), B tends to happen; for sports bikes, A is more common.
On a separate note, Bridgestone's ancient RADAC (Rayac) lugged aluminum frames
often develop wrinkles at location A over time, even without accident damage.
I have photos from a customer of an accident bike, and
the Cannondale frame was crushed right at location A—not just wrinkled but completely destroyed.
From what I could see in the photos, the fork seemed okay,
but I wouldn't recommend using it.
If there are no cracks around the lower headset cup, it might be usable,
but I can't say that with certainty.
Now, about the wheel:
No centering runout, and
just one spoke that was starting to turn sideways
and slight lateral runout in two places.
The bearings weren't perfect, but
I didn't replace them.
The left side quick-release end cap on the hub, which should normally come right off by hand,
had white rust buildup and was stuck fast. I managed to get it off,
wiped away the rust with oil, gave it a light spray of silicone lubricant, and reinstalled it.
I also applied grease to the part directly below the bearing on the hub shaft.
On a tangent here—Wako's spray can
says "silicone lubricant" on the label, not "silicon lubricant."
That's what you'd expect from a chemical company. They don't confuse silicon and silicone.
Though what I used this time wasn't Wako's product.
↑The rim in this image is rotating.
I've trued out the lateral runout to the point where it's essentially gone.
At the outermost edge, the gauge contacts at just one spot.
The bead hook is bulging slightly outward.
When you set it so the gap between rim and gauge
looks like this at nearly every phase,
there's still one phase where the gauge touches.
Also, in the image above, you can see fibers
poking through the gaps in the carbon weave.
↑Brake zone at an unaffected phase
↑Brake zone at the phase where it's slightly bulging
The carbon pattern looks rough and bumpy here.
The bead hook on the opposite side of this is fine.
Only on this side.
I marked this phase on the rim with blue tape at the beginning.
There are no traces of brake shoe melt or adhesion,
and since there are no similar spots elsewhere,
this is more likely caused by the accident impact rather than brake heat warping.
Most of the impact was probably transmitted through the frame, but
it's possible the rim took a direct hit at this spot
during the collision rather than hitting the ground.
For the wheel, I think it'll be fine to use as long as you adjust
the brake shoe contact point slightly toward the inner edge.
I placed the marking tape here.
Anyway, I may have done this customer a disservice.
An excerpt from their letter, exactly as written:
"Over the past 15 years I've been a Mavic believer and experienced several complete wheelsets, but
compared to any of them with the Nomulab No. 7, I noticed the Mavic wheels were mediocre as rotating objects."
...Damn, I'm sorry about that.