Another day with wheels (and so on).
A customer brought in the front wheel from a Reynolds Attack for me to service.
I'd already rebuilt the matching rear wheel previously.
The aluminum nipples used on Reynolds complete wheels—the ones that can be turned from the outer diameter side—
are clearly prone to loosening based on my experience,
but separately from that, there have been instances of cracking,
and this front wheel has had its nipples replaced with DT universal nipples three times in the past.
Knowing that turning the inner diameter grip would crack it, when I applied the nipple wrench, it cracked right away.
Both the manufacturer and I only adjust from the outer diameter side,
so the crack didn't happen during our work.
About this nipple—I said earlier "can be turned from the outer diameter side," but really
the outer diameter side is what's designed to be gripped,
while the inner diameter grip surface is short with rounded corners
and dimensions that are clearly minus tolerance from 3.2mm, so
if you apply a nipple wrench to the inner side out of ignorance or laziness, it strips right away.
The nipple in the image above doesn't have cracks, but
as you can see, there's no sign of it ever being gripped on the inner diameter side.
This is where I switched to DT universal nipples.
Rather than keep applying temporary fixes,
doing a complete nipple replacement seemed like the right move,
so that's what we decided to do.
The three DT black aluminum nipples could probably be reused,
but we're replacing them all anyway.
I disassembled the wheel so I could remove the DT nipples that hadn't been loosened at all.
As you can see, the spoke length is on the long side,
but that's not a mistake (more on that below).
Got it built back together.
↑The nipple at the top is what Reynolds uses,
the bottom is DT's 12mm universal nipple.
The DT one extends further inward from where it contacts the rim hole,
so the "length protruding from the rim" after subtracting the rim hole thickness
is also longer on the DT side.
I inserted the spoke into the Reynolds nipple up to where the threads begin.
The spoke enters by the depth of the gingival pocket.
I put a reference tape on it.
Then I inserted it into the DT nipple to the point where the threads begin.
The Reynolds nipple's threaded section is shifted outward compared to the universal nipple,
so the original spoke length isn't too long.
However, even accounting for the fact that the Reynolds nipple
appears shorter when it protrudes from the rim hole compared to DT,
the gingival pocket is deeper, so
I suspect this and the high frequency of cracking are related.
Universal nipples can crack too, but in those cases
white corrosion almost always appears in the gingival pocket.
The fact that cracking appears with no corrosion at this frequency
is unique to this nipple.
Since we won't be using the original nipples again,
when rebuilding, I cut the spokes a bit over 1mm shorter.
A customer brought in the front wheel from a Reynolds Attack for me to service.
I'd already rebuilt the matching rear wheel previously.
The aluminum nipples used on Reynolds complete wheels—the ones that can be turned from the outer diameter side—
are clearly prone to loosening based on my experience,
but separately from that, there have been instances of cracking,
and this front wheel has had its nipples replaced with DT universal nipples three times in the past.
Knowing that turning the inner diameter grip would crack it, when I applied the nipple wrench, it cracked right away.
Both the manufacturer and I only adjust from the outer diameter side,
so the crack didn't happen during our work.
About this nipple—I said earlier "can be turned from the outer diameter side," but really
the outer diameter side is what's designed to be gripped,
while the inner diameter grip surface is short with rounded corners
and dimensions that are clearly minus tolerance from 3.2mm, so
if you apply a nipple wrench to the inner side out of ignorance or laziness, it strips right away.
The nipple in the image above doesn't have cracks, but
as you can see, there's no sign of it ever being gripped on the inner diameter side.
This is where I switched to DT universal nipples.
Rather than keep applying temporary fixes,
doing a complete nipple replacement seemed like the right move,
so that's what we decided to do.
The three DT black aluminum nipples could probably be reused,
but we're replacing them all anyway.
I disassembled the wheel so I could remove the DT nipples that hadn't been loosened at all.
As you can see, the spoke length is on the long side,
but that's not a mistake (more on that below).
Got it built back together.
↑The nipple at the top is what Reynolds uses,
the bottom is DT's 12mm universal nipple.
The DT one extends further inward from where it contacts the rim hole,
so the "length protruding from the rim" after subtracting the rim hole thickness
is also longer on the DT side.
I inserted the spoke into the Reynolds nipple up to where the threads begin.
The spoke enters by the depth of the gingival pocket.
I put a reference tape on it.
Then I inserted it into the DT nipple to the point where the threads begin.
The Reynolds nipple's threaded section is shifted outward compared to the universal nipple,
so the original spoke length isn't too long.
However, even accounting for the fact that the Reynolds nipple
appears shorter when it protrudes from the rim hole compared to DT,
the gingival pocket is deeper, so
I suspect this and the high frequency of cracking are related.
Universal nipples can crack too, but in those cases
white corrosion almost always appears in the gingival pocket.
The fact that cracking appears with no corrosion at this frequency
is unique to this nipple.
Since we won't be using the original nipples again,
when rebuilding, I cut the spokes a bit over 1mm shorter.