I received a rear wheel built with a Stanz Centry MK3 (MTB rim) rim from a customer.
The rim bead hook was deformed due to buckle damage, so
they requested a rim replacement.
The hub is a 32H Industry Nine, and
the spokes are Pillar #14 black plain spokes on both sides,
laced in 6-cross reverse Italian (Yamaarashi) pattern.
↑This is the buckled and crushed spot. To be honest, at this level
tubeless tire air leakage could be prevented with sealant,
and you could technically keep using it as-is. So wanting to replace the rim
might just be a matter of preference. I sometimes see MTB wheels
being used with bead hooks that are worse than this.
The replacement rim is a Stanz Flow MK3, which I have on hand.
Looking at the current lineup of MTB rims with "MK3" at the end of the model name,
here are the internal/external widths (mm) listed from narrowest and lightest:
Crest MK3 23/26.3
Arch MK3 26/29.3
Flow MK3 29/32.3
Centry MK3 32/35.4
Baron MK3 35/38.4
Except for the 3.1mm difference in outer width between Flow and Centry,
all others have a 3mm difference. The appropriate tire width and intended
use changes slightly, so narrowing the width might also be part of the reason
for this rim swap.
By the way, all the rims above also come as complete wheels with model names
ending in "S1," and there's also a Major S1 wheel with 3mm wider internal
width and 3.3mm wider external width than Baron (38/41.7).
However, there's no Major MK3 rim sold as a separate product.
Something the customer themselves didn't know about this rear wheel:
it had a ridiculous amount of centering offset.
I suggested they could have the original shop that built it do a simple rim swap,
but apparently that shop no longer exists. There's not much lateral run-out,
and of course no significant radial deflection that would fill that gap.
The trend is pretty much the same regardless of where you measure.
Even measuring right below the buckling point
it's pretty much the same.
The spoke length appears to be correct. This actually creates a problem in this case,
because while those MK3 rims I mentioned have "nearly identical rim heights with different widths,"
their internal diameters are not all the same. For 29-inch rims with the same nominal specs,
Crest, Arch, and Flow are 605mm,
Centry is 603mm, and Baron is 602mm. Between Flow and Centry,
there's a 2mm diameter difference (1mm radius),
so longer spokes would be needed on one side. If it were the other way,
I could just cut them with a spoke cutter. Since the measured rim inner diameter
difference was less than 2mm, and there was that serious center offset,
the whole relationship between the spoke and nipple end faces became
completely unreliable. After considering all this, I decided to proceed
with the rim swap anyway.
The threadlocker was too strong and took effort to loosen.
It went okay in this spot, but I stripped a few nipples.
The #14 spokes have a special pitch 2mm thread,
and this threadlocker is way too high-strength for such small fasteners.
During the rim transfer... Usually I photograph the halfway point when doing
a full rotation swap, but when I transferred the rim on our shop wheel #3,
I mentioned that "with high-profile rims, it's easier to transfer one entire side."
I'm doing that here for a different reason—I'm first moving the non-drive side
to the new rim.
The image above is actually from an earlier point in the sequence,
but the reason was that almost all of the drive-side spokes
(the pulling-through direction in reverse Italian lacing) were deformed
from chain drops and needed replacement. After moving the non-damaged spokes,
I planned to remove and replace the bent ones individually, so it was easier
to approach it this way.
Done. Since it was a pure transfer job, I didn't do the conversion from
reverse Italian to JIS lacing by moving all the drive-side spokes to the next
flange hole. I also didn't lace them together with cross-lacing.
Dead center, just to be sure.
↑Drive side
↑Non-drive side
Before the rebuild, the rim was offset toward the non-drive side.
It might just be easier to tension the low-tension side (a common amateur mistake).
Centering from there by tightening the drive side further is extremely difficult,
but that's technically what happened. The idea is "non-drive side tension about the same
as original, with drive side higher due to the tightening for centering."
So the drive side spokes advanced by the amount of that extra tightening,
and while it doesn't completely cancel out the rim inner diameter difference,
it brought it to about flush or slightly negative. The non-drive side shows
almost the full rim inner diameter difference. I've cracked the split slightly,
but I prioritized spoke reuse, so that's a trade-off.
↑Replaced spokes
I replaced them with DT black champion spokes. Seven of the eight drive-side spokes
on the 32H hub. Maybe I should have replaced all eight while I was at it.
If the original state had been perfectly centered, making just these seven spokes
about 1mm longer would give the proper length, but that would complicate
the early stages of wheel building. For the drive side this time,
I figured the centering tightening and rim inner diameter difference would
balance out, so I cut them to the original length. When I wrote earlier
that the original spoke length "appears correct," it's because when centered,
the drive-side spokes should stick out about 1mm longer than the non-drive side,
but due to that horrible center offset, they happened to be flush on both sides.
To put it another way: if the original state had been centered,
the drive side would be about +1mm and non-drive side correct,
but after changing rims, the drive side became correct and non-drive side
is about -1mm.
The rim bead hook was deformed due to buckle damage, so
they requested a rim replacement.
The hub is a 32H Industry Nine, and
the spokes are Pillar #14 black plain spokes on both sides,
laced in 6-cross reverse Italian (Yamaarashi) pattern.
↑This is the buckled and crushed spot. To be honest, at this level
tubeless tire air leakage could be prevented with sealant,
and you could technically keep using it as-is. So wanting to replace the rim
might just be a matter of preference. I sometimes see MTB wheels
being used with bead hooks that are worse than this.
The replacement rim is a Stanz Flow MK3, which I have on hand.
Looking at the current lineup of MTB rims with "MK3" at the end of the model name,
here are the internal/external widths (mm) listed from narrowest and lightest:
Crest MK3 23/26.3
Arch MK3 26/29.3
Flow MK3 29/32.3
Centry MK3 32/35.4
Baron MK3 35/38.4
Except for the 3.1mm difference in outer width between Flow and Centry,
all others have a 3mm difference. The appropriate tire width and intended
use changes slightly, so narrowing the width might also be part of the reason
for this rim swap.
By the way, all the rims above also come as complete wheels with model names
ending in "S1," and there's also a Major S1 wheel with 3mm wider internal
width and 3.3mm wider external width than Baron (38/41.7).
However, there's no Major MK3 rim sold as a separate product.
Something the customer themselves didn't know about this rear wheel:
it had a ridiculous amount of centering offset.
I suggested they could have the original shop that built it do a simple rim swap,
but apparently that shop no longer exists. There's not much lateral run-out,
and of course no significant radial deflection that would fill that gap.
The trend is pretty much the same regardless of where you measure.
Even measuring right below the buckling point
it's pretty much the same.
The spoke length appears to be correct. This actually creates a problem in this case,
because while those MK3 rims I mentioned have "nearly identical rim heights with different widths,"
their internal diameters are not all the same. For 29-inch rims with the same nominal specs,
Crest, Arch, and Flow are 605mm,
Centry is 603mm, and Baron is 602mm. Between Flow and Centry,
there's a 2mm diameter difference (1mm radius),
so longer spokes would be needed on one side. If it were the other way,
I could just cut them with a spoke cutter. Since the measured rim inner diameter
difference was less than 2mm, and there was that serious center offset,
the whole relationship between the spoke and nipple end faces became
completely unreliable. After considering all this, I decided to proceed
with the rim swap anyway.
The threadlocker was too strong and took effort to loosen.
It went okay in this spot, but I stripped a few nipples.
The #14 spokes have a special pitch 2mm thread,
and this threadlocker is way too high-strength for such small fasteners.
During the rim transfer... Usually I photograph the halfway point when doing
a full rotation swap, but when I transferred the rim on our shop wheel #3,
I mentioned that "with high-profile rims, it's easier to transfer one entire side."
I'm doing that here for a different reason—I'm first moving the non-drive side
to the new rim.
The image above is actually from an earlier point in the sequence,
but the reason was that almost all of the drive-side spokes
(the pulling-through direction in reverse Italian lacing) were deformed
from chain drops and needed replacement. After moving the non-damaged spokes,
I planned to remove and replace the bent ones individually, so it was easier
to approach it this way.
Done. Since it was a pure transfer job, I didn't do the conversion from
reverse Italian to JIS lacing by moving all the drive-side spokes to the next
flange hole. I also didn't lace them together with cross-lacing.
Dead center, just to be sure.
↑Drive side
↑Non-drive side
Before the rebuild, the rim was offset toward the non-drive side.
It might just be easier to tension the low-tension side (a common amateur mistake).
Centering from there by tightening the drive side further is extremely difficult,
but that's technically what happened. The idea is "non-drive side tension about the same
as original, with drive side higher due to the tightening for centering."
So the drive side spokes advanced by the amount of that extra tightening,
and while it doesn't completely cancel out the rim inner diameter difference,
it brought it to about flush or slightly negative. The non-drive side shows
almost the full rim inner diameter difference. I've cracked the split slightly,
but I prioritized spoke reuse, so that's a trade-off.
↑Replaced spokes
I replaced them with DT black champion spokes. Seven of the eight drive-side spokes
on the 32H hub. Maybe I should have replaced all eight while I was at it.
If the original state had been perfectly centered, making just these seven spokes
about 1mm longer would give the proper length, but that would complicate
the early stages of wheel building. For the drive side this time,
I figured the centering tightening and rim inner diameter difference would
balance out, so I cut them to the original length. When I wrote earlier
that the original spoke length "appears correct," it's because when centered,
the drive-side spokes should stick out about 1mm longer than the non-drive side,
but due to that horrible center offset, they happened to be flush on both sides.
To put it another way: if the original state had been centered,
the drive side would be about +1mm and non-drive side correct,
but after changing rims, the drive side became correct and non-drive side
is about -1mm.