Today it's wheels again (and so on).
↑This is the rear wheel I rebuilt yesterday.
In the article, I initially referred to the Cosmic Pro Carbon SL as having a "UST" designation,
but these front and rear wheels turned out to not be Road UST tubeless after all.
The cosmetic detailing on the rim has "Cosmic" written in large letters at three locations spaced 120° apart.
↑A while back there was an instance where I reused everything except the rim and nipples from the UST wheels,
and the cosmetic detailing on this rim is extremely simple.
The tire also has a single yellow triangle that's meant to be aligned with a yellow line on the rim.
As for why this happened,
while the manufacturer hasn't explicitly confirmed it,
there's a reason I'm almost certain about.
When Road UST tubeless first came out,
the tubeless tires (first generation) that supported it had such a loose fit on the rim
that the manufacturer actually emphasized how easy they were to handle—so easy
that even people with weak hands didn't need tire levers.
So it was definitely intentional, but for some reason or other,
starting with later production batches, the second-generation tires became extremely difficult to remove.
At the time I wondered if the wheel dimensions had changed,
but the logistics of that would've been impossible,
and given that second-generation tires didn't fit well on wheels that had first-gen tires,
it's certain the tires changed instead.
And when you tried to mount those second-generation tires on a rim,
the tire bead wouldn't seat properly,
and tire levers would frequently slip and scrape the rim sidewalls—
↑These are images from a different wheel, but
you could see rim sidewall stickers peeling off everywhere like this—
that's my theory for why the rim sidewall cosmetics became simpler.
By the way, the current tire is the third generation.
The third generation isn't as loose as the first,
but it's easy enough for an amateur to handle if they get a flat in the field.
With the second generation, there were cases where people couldn't remove the tire after a puncture in the mountains,
so they had to call a tow truck
(using the free roadside assistance that comes with car insurance a few times a year)—
I've heard that story from several unrelated incidents.
Anyway, today it's wheels again (and so on).
I'll rebuild the front wheel.
The spokes are heavily rusted,
so much that rust powder comes off when you touch them.
Actually, spokes that rust this badly are thought to be less prone to nipple end breakage,
but that doesn't mean most people would find this acceptable.
A while back I rebuilt a wheel by reusing the hub and spokes with a non-Mavic rim of the same depth
and iridescent nipples, and those spokes were also slightly rusted.
Still, I reused the spokes because this wheel's hub and spokes have an inseparable relationship.
This is an image from the article about the rear wheel with simpler cosmetics
(now that I look at it, it's got a fair bit of rust on it).
Even in Mavic Cosmic-series wheels,
the straight spokes have the final part of the nipple end butted to #13 (2.3mm),
which reduces the risk of nipple end breakage,
but the hub flange catch fit doesn't match the #14 (2.0mm) specification, so it's apparently
the case that wheels with #13 butted nipple ends can't be serviced with standard straight spokes—possibly.
So the parts I wrote in red are things I don't have confirmed certainty about,
but
this time I tested it.
...No good.
The dedicated spokes click into place perfectly,
but you don't get that satisfying feeling with #14 straight nipple end spokes.
I can't say the wheel absolutely won't build,
but I can't build a wheel I'd hand over to a customer.
We're holding a fixed-gear hub for the rear,
and the plan was to either reuse the front hub if possible,
or source an 18H hub somehow at our shop if not.
Oh, unrelated to this, here's an image of the front hub's bearing area.
We're currently holding a Ksyrium Pro (Shimano-branded version) with various issues,
and I'll reference this image at that time.
↑This is when the rear rim was just a rim.
I mentioned that the two dots next to the valve hole indicate a rear rim,
but they also contain information about left and right.
Aluminum Ksyrium and R-SYS rims are offset rims, so you can't get left and right wrong,
but on this rear rim, the top side of the image is the freewheel side.
There'sa ridge-like a straight ridge running down the center of the rim,
and subtly, the holes on the non-freewheel side (where spoke angles are more laid-back)
are positioned further from the ridge.
This doesn't just look that way in one spot—it's like that on all the holes.
If this were an aluminum rim with Duralumin spoke holes,
with one side tangent-laced and one side radial-laced,
there would be such strong directionality
you couldn't get left and right wrong
(though Ksyrium and R-SYS have the radial side reversed,
so in theory you could intentionally misalign the rim offset and build a wheel with,
say, a Ksyrium hub and R-SYS rim).
But with a Cosmic rim's degree of spoke hole offset,
it's possible to build the rim backward.
And here's this front rim.
Being a braking surface on the front, the spoke hole offset is symmetric left and right,
but both holes are offset so much that the rim ridge is nearly tangent,
and they're offset further outward than the non-freewheel side of the rear rim.
It's dedicated design work relative to one hub flange width,
but from a non-professional perspective, it's hard to appreciate.
This rim is 18H, but hypothetically if it were 20H or 24H,
and you asked if you could build a rear wheel with a rear hub that has the same spoke count,
you could. The universal nipple's ball-joint-like shape at the base
gives a lot of tolerance.
Built it.
They'll supply 18H front hubs but skip 28H and only supply 24H and 32H rear hubs.
660 hub, 18H, black CX Sprint (rim-brake) radial-laced
with black aluminum nipples.
By chance, I had the opportunity to weigh both front and rear rims
of the same Cosmic Pro Carbon wheels (UST versions),
and while my sample size is small and the UST front rim seems to have some weight loss,
I can't say for certain, but it's possible
the rim didn't even get heavier with the tubeless conversion.
Of course, I don't intend to share specific weights.
↑Man, this guy's got bad vibes
Sorry For The Wait! Please Check Out This Image!
Non-UST Front Rim!
Non-UST Rear Rim!
So You Don't Have To Hunt Through Old Posts!
Here They Are For Reference!
New Cosmic Road UST Front And Rear Rims!
↑Stop iiiiiit!
↑This is the rear wheel I rebuilt yesterday.
In the article, I initially referred to the Cosmic Pro Carbon SL as having a "UST" designation,
but these front and rear wheels turned out to not be Road UST tubeless after all.
The cosmetic detailing on the rim has "Cosmic" written in large letters at three locations spaced 120° apart.
↑A while back there was an instance where I reused everything except the rim and nipples from the UST wheels,
and the cosmetic detailing on this rim is extremely simple.
The tire also has a single yellow triangle that's meant to be aligned with a yellow line on the rim.
As for why this happened,
while the manufacturer hasn't explicitly confirmed it,
there's a reason I'm almost certain about.
When Road UST tubeless first came out,
the tubeless tires (first generation) that supported it had such a loose fit on the rim
that the manufacturer actually emphasized how easy they were to handle—so easy
that even people with weak hands didn't need tire levers.
So it was definitely intentional, but for some reason or other,
starting with later production batches, the second-generation tires became extremely difficult to remove.
At the time I wondered if the wheel dimensions had changed,
but the logistics of that would've been impossible,
and given that second-generation tires didn't fit well on wheels that had first-gen tires,
it's certain the tires changed instead.
And when you tried to mount those second-generation tires on a rim,
the tire bead wouldn't seat properly,
and tire levers would frequently slip and scrape the rim sidewalls—
↑These are images from a different wheel, but
you could see rim sidewall stickers peeling off everywhere like this—
that's my theory for why the rim sidewall cosmetics became simpler.
By the way, the current tire is the third generation.
The third generation isn't as loose as the first,
but it's easy enough for an amateur to handle if they get a flat in the field.
With the second generation, there were cases where people couldn't remove the tire after a puncture in the mountains,
so they had to call a tow truck
(using the free roadside assistance that comes with car insurance a few times a year)—
I've heard that story from several unrelated incidents.
Anyway, today it's wheels again (and so on).
I'll rebuild the front wheel.
The spokes are heavily rusted,
so much that rust powder comes off when you touch them.
Actually, spokes that rust this badly are thought to be less prone to nipple end breakage,
but that doesn't mean most people would find this acceptable.
A while back I rebuilt a wheel by reusing the hub and spokes with a non-Mavic rim of the same depth
and iridescent nipples, and those spokes were also slightly rusted.
Still, I reused the spokes because this wheel's hub and spokes have an inseparable relationship.
This is an image from the article about the rear wheel with simpler cosmetics
Even in Mavic Cosmic-series wheels,
the straight spokes have the final part of the nipple end butted to #13 (2.3mm),
which reduces the risk of nipple end breakage,
but the hub flange catch fit doesn't match the #14 (2.0mm) specification, so it's apparently
the case that wheels with #13 butted nipple ends can't be serviced with standard straight spokes—possibly.
So the parts I wrote in red are things I don't have confirmed certainty about,
but
this time I tested it.
...No good.
The dedicated spokes click into place perfectly,
but you don't get that satisfying feeling with #14 straight nipple end spokes.
I can't say the wheel absolutely won't build,
but I can't build a wheel I'd hand over to a customer.
We're holding a fixed-gear hub for the rear,
and the plan was to either reuse the front hub if possible,
or source an 18H hub somehow at our shop if not.
Oh, unrelated to this, here's an image of the front hub's bearing area.
We're currently holding a Ksyrium Pro (Shimano-branded version) with various issues,
and I'll reference this image at that time.
↑This is when the rear rim was just a rim.
I mentioned that the two dots next to the valve hole indicate a rear rim,
but they also contain information about left and right.
Aluminum Ksyrium and R-SYS rims are offset rims, so you can't get left and right wrong,
but on this rear rim, the top side of the image is the freewheel side.
There's
and subtly, the holes on the non-freewheel side (where spoke angles are more laid-back)
are positioned further from the ridge.
This doesn't just look that way in one spot—it's like that on all the holes.
If this were an aluminum rim with Duralumin spoke holes,
with one side tangent-laced and one side radial-laced,
there would be such strong directionality
you couldn't get left and right wrong
(though Ksyrium and R-SYS have the radial side reversed,
so in theory you could intentionally misalign the rim offset and build a wheel with,
say, a Ksyrium hub and R-SYS rim).
But with a Cosmic rim's degree of spoke hole offset,
it's possible to build the rim backward.
And here's this front rim.
Being a braking surface on the front, the spoke hole offset is symmetric left and right,
but both holes are offset so much that the rim ridge is nearly tangent,
and they're offset further outward than the non-freewheel side of the rear rim.
It's dedicated design work relative to one hub flange width,
but from a non-professional perspective, it's hard to appreciate.
This rim is 18H, but hypothetically if it were 20H or 24H,
and you asked if you could build a rear wheel with a rear hub that has the same spoke count,
you could. The universal nipple's ball-joint-like shape at the base
gives a lot of tolerance.
Built it.
They'll supply 18H front hubs but skip 28H and only supply 24H and 32H rear hubs.
660 hub, 18H, black CX Sprint (rim-brake) radial-laced
with black aluminum nipples.
By chance, I had the opportunity to weigh both front and rear rims
of the same Cosmic Pro Carbon wheels (UST versions),
and while my sample size is small and the UST front rim seems to have some weight loss,
I can't say for certain, but it's possible
the rim didn't even get heavier with the tubeless conversion.
Of course, I don't intend to share specific weights.
↑Man, this guy's got bad vibes
Sorry For The Wait! Please Check Out This Image!
Non-UST Front Rim!
Non-UST Rear Rim!
So You Don't Have To Hunt Through Old Posts!
Here They Are For Reference!
New Cosmic Road UST Front And Rear Rims!
↑Stop iiiiiit!