A customer left a Cosmic Carbon 40C with me for service.
The "40C" designation means a 40mm rim height with a clincher rim.
I received it a while back,
but I'm only posting about it now because I needed to do some research first.
The reason the customer brought it in was to check for runout and centering on this new wheel.
Neither issue was serious, so the work was finished quickly.
↑This new rim is really impressive.
It's easy to point out its weaknesses.
Generally speaking, having a carbon braking surface puts you at a disadvantage compared to aluminum when it comes to stopping power.
However, at least in dry conditions,
recent carbon rim and dedicated brake shoe combinations
offer braking performance that's comparable to aluminum,
so if Mavic has overcome this known drawback and delivered even greater advantages with this wheel,
that's fine—and they clearly believed so, otherwise they wouldn't have released it.
The bead area is aluminum.
What the manufacturer seems concerned about isn't braking performance
but rather issues like buckling and heat damage.
Given the bonding surface area between aluminum and carbon,
this hybrid rim design should be strong against delamination issues that typically plague this type of construction.
The outer rim weight is reduced too.
The finish is extremely clean.
↑This mackerel-stew-looking object is a cut sample of the Cosmic Carbon SLR.
The Cosmic Carbon Ultimate was the first wheel to use this design,
where chevron-shaped spokes run across the flanges
and connect rim holes on opposite sides,
but it has no adjustment mechanisms
(in fact, they were omitted to achieve stiffness and lightness).
The Cosmic Carbon SLR then added adjustment elements,
but the structure was a bit of a "I understand what you're going for, but is this the right approach?" kind of thing.
Though I actually do like it.
But it ended up disappearing anyway.
Anyway, about the balance of aluminum and carbon.
If you're confident in the carbon braking zone,
wouldn't the Cosmic Carbon 40C approach be more elegant?
Not that it matters much, but when the entire rim is carbon,
it really looks like a tubular tire at first glance when you put on
a Vittoria or Veloflex open tubular WO tire (especially with that tan sidewall).
That's kind of nice.
Looking at Mavic's site, the rim molding technology for both the Cosmic Carbon Ultimate and the 40C is called "TgMAX,"
but the cut sample in the image shows what looks like polyurethane foam filling inside the rim.
However, the inner surface of the 40C is a bit squishy when you pinch it with your fingers,
so at least that section must be hollow.
Speaking of carbon rims filled with polyurethane foam, that's Corima.
The cosmetic carbon on the surface layer of the Ultimate's rim looks nearly identical to Corima's,
and given they're both French manufacturers, wait what am I
The "40C" designation means a 40mm rim height with a clincher rim.
I received it a while back,
but I'm only posting about it now because I needed to do some research first.
The reason the customer brought it in was to check for runout and centering on this new wheel.
Neither issue was serious, so the work was finished quickly.
↑This new rim is really impressive.
It's easy to point out its weaknesses.
Generally speaking, having a carbon braking surface puts you at a disadvantage compared to aluminum when it comes to stopping power.
However, at least in dry conditions,
recent carbon rim and dedicated brake shoe combinations
offer braking performance that's comparable to aluminum,
so if Mavic has overcome this known drawback and delivered even greater advantages with this wheel,
that's fine—and they clearly believed so, otherwise they wouldn't have released it.
The bead area is aluminum.
What the manufacturer seems concerned about isn't braking performance
but rather issues like buckling and heat damage.
Given the bonding surface area between aluminum and carbon,
this hybrid rim design should be strong against delamination issues that typically plague this type of construction.
The outer rim weight is reduced too.
The finish is extremely clean.
↑This mackerel-stew-looking object is a cut sample of the Cosmic Carbon SLR.
The Cosmic Carbon Ultimate was the first wheel to use this design,
where chevron-shaped spokes run across the flanges
and connect rim holes on opposite sides,
but it has no adjustment mechanisms
(in fact, they were omitted to achieve stiffness and lightness).
The Cosmic Carbon SLR then added adjustment elements,
but the structure was a bit of a "I understand what you're going for, but is this the right approach?" kind of thing.
Though I actually do like it.
But it ended up disappearing anyway.
Anyway, about the balance of aluminum and carbon.
If you're confident in the carbon braking zone,
wouldn't the Cosmic Carbon 40C approach be more elegant?
Not that it matters much, but when the entire rim is carbon,
it really looks like a tubular tire at first glance when you put on
a Vittoria or Veloflex open tubular WO tire (especially with that tan sidewall).
That's kind of nice.
Looking at Mavic's site, the rim molding technology for both the Cosmic Carbon Ultimate and the 40C is called "TgMAX,"
but the cut sample in the image shows what looks like polyurethane foam filling inside the rim.
However, the inner surface of the 40C is a bit squishy when you pinch it with your fingers,
so at least that section must be hollow.
Speaking of carbon rims filled with polyurethane foam, that's Corima.
The cosmetic carbon on the surface layer of the Ultimate's rim looks nearly identical to Corima's,
and given they're both French manufacturers, wait what am I
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