Another day of wheels (and so on).
A customer brought in a rear wheel built with Tni's ROAD 50 carbon rim.
The rim is the same one used in the Nomu Lab Wheel No. 2.5.
There's a marking tape on one spoke, and
this spoke alone has lost its tension—
when I pinch it with my fingers and shake it, it moves all over the place.
In chronological order this came later, but
I checked the rim alone against a glass surface plate and
confirmed the rim wasn't warped.
Carbon rims warping like a potato chip in the same way as metal rims is a rare case,
but it does happen occasionally.
The customer's request is to make it tighter, and they said rebuilding the wheel is an option too. Leave it to me!
Wing Hub 24H, full competition four-cross laced,
and the non-drive side is radial spoking.
Of course I'm going with a semi-competition four-cross laced pattern,
and I'll try to reuse the drive-side spokes if possible.
"If possible" means the spokes have no deformation and
the length is correct (by my standards, mind you) or longer.
If they're shorter there's nothing to be done, but
if they're longer I can cut them down.
When I actually checked, they were about 2mm too long, so I cut them.
The nipples are aluminum both before and after reassembly, and I replaced all of them,
but given how loose the tension was, they were pretty damaged, so
in some places the spokes might have been fully seated.
My rule for reusing spokes:
"Radial spokes become radial spokes again,
and crossed spokes become crossed spokes again."
I followed this rule again this time.
I don't have sufficient reliable statistics to confirm whether breaking this rule actually increases the probability of spoke breakage,
but—
↑originally crossed spoke
↑originally radial spoke
Failing to distinguish between these two
seems like a pretty obvious problem, doesn't it?
Going back in time, here's the centering check I did before disassembling the wheel.
The rim is pulled toward the drive side, but at this point the drive-side tension
was about 85% of what I normally use for the drive side in a competition build,
based on the H1ST reading (first spoke tension) on a Hozan tension meter.
The idea that increasing the 1st ST by 15% and increasing the 2nd ST by 15% aren't the same thing
can be explained with "beaker theory," and that's something I want to write about soon.
It'll probably take a full day.
In other words, starting from a rim pulled to the drive side, I further tighten the drive side,
increasing the centering error while tensioning up to just before the dead end,
and then I can center the wheel by tightening the non-drive side—
this way you're tightening both sides while centering.
If I do this well, the wheel would be a bit better,
but I want a much better wheel, so
I rebuilt it.
Wing Hub 24H, semi-competition four-cross laced with interlaced pattern.
The only parts I replaced were the non-drive-side spokes and
the nipples with new ones of the same type—everything else is reused.
The original wheel had its tire mounted with rim cement, so
it actually saw use, but from my perspective
it was like putting a tire on an incompletely built wheel.
If the original wheel condition had made you think "hand-built wheels don't ride very well,"
I'm confident that misconception is now cleared up.
This ROAD 50 rim is from 2014, but
the label says the maximum tension is 100 kgf.
In the current model (the rim in the image is from 2017), this has been changed to 120 kgf,
but honestly, I can't tell what changed.
The ROAD 38 rim, which is the rim for Nomu Lab Wheel No. 2, had 130 kgf printed on it at one point,
but the current version says 120 kgf.
Rather, rims that used to vary between 100 kgf and 130 kgf have been standardized at 120 kgf.
The ROAD 38 rim doesn't feel different to build depending on the year.
A customer brought in a rear wheel built with Tni's ROAD 50 carbon rim.
The rim is the same one used in the Nomu Lab Wheel No. 2.5.
There's a marking tape on one spoke, and
this spoke alone has lost its tension—
when I pinch it with my fingers and shake it, it moves all over the place.
In chronological order this came later, but
I checked the rim alone against a glass surface plate and
confirmed the rim wasn't warped.
Carbon rims warping like a potato chip in the same way as metal rims is a rare case,
but it does happen occasionally.
The customer's request is to make it tighter, and they said rebuilding the wheel is an option too. Leave it to me!
Wing Hub 24H, full competition four-cross laced,
and the non-drive side is radial spoking.
Of course I'm going with a semi-competition four-cross laced pattern,
and I'll try to reuse the drive-side spokes if possible.
"If possible" means the spokes have no deformation and
the length is correct (by my standards, mind you) or longer.
If they're shorter there's nothing to be done, but
if they're longer I can cut them down.
When I actually checked, they were about 2mm too long, so I cut them.
The nipples are aluminum both before and after reassembly, and I replaced all of them,
but given how loose the tension was, they were pretty damaged, so
in some places the spokes might have been fully seated.
My rule for reusing spokes:
"Radial spokes become radial spokes again,
and crossed spokes become crossed spokes again."
I followed this rule again this time.
I don't have sufficient reliable statistics to confirm whether breaking this rule actually increases the probability of spoke breakage,
but—
↑originally crossed spoke
↑originally radial spoke
Failing to distinguish between these two
seems like a pretty obvious problem, doesn't it?
Going back in time, here's the centering check I did before disassembling the wheel.
The rim is pulled toward the drive side, but at this point the drive-side tension
was about 85% of what I normally use for the drive side in a competition build,
based on the H1ST reading (first spoke tension) on a Hozan tension meter.
The idea that increasing the 1st ST by 15% and increasing the 2nd ST by 15% aren't the same thing
can be explained with "beaker theory," and that's something I want to write about soon.
It'll probably take a full day.
In other words, starting from a rim pulled to the drive side, I further tighten the drive side,
increasing the centering error while tensioning up to just before the dead end,
and then I can center the wheel by tightening the non-drive side—
this way you're tightening both sides while centering.
If I do this well, the wheel would be a bit better,
but I want a much better wheel, so
I rebuilt it.
Wing Hub 24H, semi-competition four-cross laced with interlaced pattern.
The only parts I replaced were the non-drive-side spokes and
the nipples with new ones of the same type—everything else is reused.
The original wheel had its tire mounted with rim cement, so
it actually saw use, but from my perspective
it was like putting a tire on an incompletely built wheel.
If the original wheel condition had made you think "hand-built wheels don't ride very well,"
I'm confident that misconception is now cleared up.
This ROAD 50 rim is from 2014, but
the label says the maximum tension is 100 kgf.
In the current model (the rim in the image is from 2017), this has been changed to 120 kgf,
but honestly, I can't tell what changed.
The ROAD 38 rim, which is the rim for Nomu Lab Wheel No. 2, had 130 kgf printed on it at one point,
but the current version says 120 kgf.
Rather, rims that used to vary between 100 kgf and 130 kgf have been standardized at 120 kgf.
The ROAD 38 rim doesn't feel different to build depending on the year.