Another day in the wheel shop (et cetera).
A customer brought in a pair of 50mm tall carbon tubular rims
front and rear wheels. I built these myself back in the day.
Front wheel: BITEX (or similar) hub, 20H, black CX-RAY outpoke radial laced,
Rear wheel: Evo hub, 24H, all CX-RAY, 4x lacing with tied spokes. Back then I couldn't tie with black spokes,
so I had to make do with spokes of different colors on either side.
My apologies for that at the time.
And here's the messiest spot, sorry about the sloppy soldering work back then.
This is a Shimano 10-speed era Evo hub,
but the customer had the splines turned on a lathe to convert it to 11-speed.
The customer wants these wheels rebuilt with a wide rim of the same height.
The original narrow rim was filled with foam polyurethane,
constructed like a Kolima rim.
The rim height is nearly identical at about 50mm—both are precisely 49.8mm—but
the wall thickness on the inner side of the spoke hole differs.
I was able to reuse the original spokes, but had to cut them a bit shorter.
So reconverting from wide rim back to narrow rim isn't possible.
Front wheel is built.
Same lacing pattern as before the rebuild.
Rear wheel is built.
I replaced the non-drive side spokes with new black ones.
Untying and reusing the tied spokes wasn't feasible,
so while a rim swap is possible if spoke lengths match,
since they differ, new spokes were needed anyway.
When I pulled the drive-side spokes from the hub flanges, I separated
the original inpokes from the original outpokes, so that
when reusing them they'd be laced the same way.
↑Black ties
Replaced all the red nipples too.
Going back in time chronologically, here's the rear wheel before the rebuild.
The customer's memo shows 685g.
I weighed it.
A 2g difference isn't a big deal really.
I'm planning to write soon about "the holy land of weight reduction,"
but the difference is more likely due to scale variation than
gravity differences at the measurement location, and
if I'd weighed this rear wheel on the customer's scale
it might've read 683g anyway.
Since it'll probably come out eventually, I'll get ahead of it now—
↑Narrow front rim before rebuild (estimated weight ~10g)
↑Wide front rim after rebuild
↑Narrow rear rim before rebuild (no weight)
↑Wide rear rim after rebuild
The pre-rebuild rims were actually extremely good in terms of height-to-weight ratio.
For example, the rim on Nomu Lab Wheel #2 is 38mm / 347g.
I hope this rebuild nets stiffness and aerodynamic benefits to overcome the weight penalty, but... hmm.
Incidentally, the spoke tension was slack right before the rebuild (especially front),
so the tension after tightening to proper specs and the post-rebuild tension are about the same.
Which means if you ride the new wheel and think "it feels stiffer!"—
the difference in spoke tension matters far more than rim stiffness.
If asked to build a wheel with the old rim that feels just as stiff as the new one,
I could do it. Building with a stiff rim doesn't automatically make a stiff wheel.
Where the old rim is clearly inferior to the new one:
The old rim has a brake surface finish more prone to heat-sag.
The front has mostly Yellow King (the big caterpillar one) and
the rear has what's presumably Black Prince or some other black shoe (the red caterpillar),
with welding spatter on both, but
neither brake zone has deformed into an uneven state,
so reuse was feasible.
before
after
before
after
Wiped clean with acetone.
Just under the tape marker though.
I'll do the full circumference later.
A customer brought in a pair of 50mm tall carbon tubular rims
front and rear wheels. I built these myself back in the day.
Front wheel: BITEX (or similar) hub, 20H, black CX-RAY outpoke radial laced,
Rear wheel: Evo hub, 24H, all CX-RAY, 4x lacing with tied spokes. Back then I couldn't tie with black spokes,
so I had to make do with spokes of different colors on either side.
My apologies for that at the time.
And here's the messiest spot, sorry about the sloppy soldering work back then.
This is a Shimano 10-speed era Evo hub,
but the customer had the splines turned on a lathe to convert it to 11-speed.
The customer wants these wheels rebuilt with a wide rim of the same height.
The original narrow rim was filled with foam polyurethane,
constructed like a Kolima rim.
The rim height is nearly identical at about 50mm—both are precisely 49.8mm—but
the wall thickness on the inner side of the spoke hole differs.
I was able to reuse the original spokes, but had to cut them a bit shorter.
So reconverting from wide rim back to narrow rim isn't possible.
Front wheel is built.
Same lacing pattern as before the rebuild.
Rear wheel is built.
I replaced the non-drive side spokes with new black ones.
Untying and reusing the tied spokes wasn't feasible,
so while a rim swap is possible if spoke lengths match,
since they differ, new spokes were needed anyway.
When I pulled the drive-side spokes from the hub flanges, I separated
the original inpokes from the original outpokes, so that
when reusing them they'd be laced the same way.
↑Black ties
Replaced all the red nipples too.
Going back in time chronologically, here's the rear wheel before the rebuild.
The customer's memo shows 685g.
I weighed it.
A 2g difference isn't a big deal really.
I'm planning to write soon about "the holy land of weight reduction,"
but the difference is more likely due to scale variation than
gravity differences at the measurement location, and
if I'd weighed this rear wheel on the customer's scale
it might've read 683g anyway.
Since it'll probably come out eventually, I'll get ahead of it now—
↑Narrow front rim before rebuild (estimated weight ~10g)
↑Wide front rim after rebuild
↑Narrow rear rim before rebuild (no weight)
↑Wide rear rim after rebuild
The pre-rebuild rims were actually extremely good in terms of height-to-weight ratio.
For example, the rim on Nomu Lab Wheel #2 is 38mm / 347g.
I hope this rebuild nets stiffness and aerodynamic benefits to overcome the weight penalty, but... hmm.
Incidentally, the spoke tension was slack right before the rebuild (especially front),
so the tension after tightening to proper specs and the post-rebuild tension are about the same.
Which means if you ride the new wheel and think "it feels stiffer!"—
the difference in spoke tension matters far more than rim stiffness.
If asked to build a wheel with the old rim that feels just as stiff as the new one,
I could do it. Building with a stiff rim doesn't automatically make a stiff wheel.
Where the old rim is clearly inferior to the new one:
The old rim has a brake surface finish more prone to heat-sag.
The front has mostly Yellow King (the big caterpillar one) and
the rear has what's presumably Black Prince or some other black shoe (the red caterpillar),
with welding spatter on both, but
neither brake zone has deformed into an uneven state,
so reuse was feasible.
before
after
before
after
Wiped clean with acetone.
Just under the tape marker though.
I'll do the full circumference later.