The Tni Carbon 38 (the rim for Nomu Lab Wheel No. 2) comes in
18, 20, 24, and 28H configurations, but
the 24H and 28H are designated as "rear use,"
with a sticker instructing which direction to orient
the freewheel body when assembling.
Looking at the actual hole pattern and spoke hole positions on the rim,
I don't see it as a distinctly asymmetrical rim,
but since the manufacturer specifies it as rear-use, using it on the front doesn't seem right.
(Using a front-designated rim on the rear is OK, though.)
The same sticker appears on the Cosmic Carbone 80 as well,
but I shouldn't think too deeply about it.
I want to build Nomu Lab Wheel No. 2 as a disc brake-compatible front wheel for cyclocross,
but disc brake front hubs have
offset flange widths due to the rotor mounting surface.
With these types of hubs, the exception is that "left flange width < right flange width."
The diagram above uses the current XTRA HB-M985 as an example,
where the R-L difference is 10.8mm in this case.
With a hub like this,
using the offset rim in reverse can reduce wobble (ochoko)
and correct the left-right difference in spoke tension.
Road rims range from about 18mm on the narrow side to nearly 22mm on the wide side.
Let's say the average is around 20mm.
Even if we offset the rim to the point where one side becomes a sheer cliff,
we can't achieve half the rim width—around 10mm of offset.
As shown in the diagram, we have to account for the rim thickness and nipple flange thickness.
Even pushing it to the limit, we won't get close to 10mm of offset.
The HB-M985 mentioned earlier had a flange width difference of 10.8mm,
so even using a maximally offset rim in reverse won't reverse the wobble.
However, it will definitely shift in the correction direction, so my view is that,
if possible, using an asymmetrical rim on the front wheel of a disc brake front hub is worth doing.
For the rear wheel, even with a disc brake hub,
the freewheel side has the narrower flange width, so
↑using the offset rim in the normal way is the correct approach.
If only there were 24H or 28H disc brake-specific hubs available
(the rear overlock nut dimension is 135mm),
but they're hard to come by.
The 960-series XTRA 965 hub came in 36, 32, 28, and 24H configurations,
the 970-series XTRA 975 hub in 36, 32, and 28H,
but the current 985 hub only comes in 32H.
Soul Cycles and Chris King do offer 28H (for six-bolt rotors)
from a catalog standpoint (though dealer stock is another matter).
But the price is astronomical.
Since building a cyclocross wheel is ultimately an adaptation,
and "hand-built MTB 28H rim wheels" is such a niche market,
it makes sense that hubs for that purpose are scarce too.
Hmm, quite the dilemma.
18, 20, 24, and 28H configurations, but
the 24H and 28H are designated as "rear use,"
with a sticker instructing which direction to orient
the freewheel body when assembling.
Looking at the actual hole pattern and spoke hole positions on the rim,
I don't see it as a distinctly asymmetrical rim,
but since the manufacturer specifies it as rear-use, using it on the front doesn't seem right.
(Using a front-designated rim on the rear is OK, though.)
The same sticker appears on the Cosmic Carbone 80 as well,
but I shouldn't think too deeply about it.
I want to build Nomu Lab Wheel No. 2 as a disc brake-compatible front wheel for cyclocross,
but disc brake front hubs have
offset flange widths due to the rotor mounting surface.
With these types of hubs, the exception is that "left flange width < right flange width."
The diagram above uses the current XTRA HB-M985 as an example,
where the R-L difference is 10.8mm in this case.
With a hub like this,
using the offset rim in reverse can reduce wobble (ochoko)
and correct the left-right difference in spoke tension.
Road rims range from about 18mm on the narrow side to nearly 22mm on the wide side.
Let's say the average is around 20mm.
Even if we offset the rim to the point where one side becomes a sheer cliff,
we can't achieve half the rim width—around 10mm of offset.
As shown in the diagram, we have to account for the rim thickness and nipple flange thickness.
Even pushing it to the limit, we won't get close to 10mm of offset.
The HB-M985 mentioned earlier had a flange width difference of 10.8mm,
so even using a maximally offset rim in reverse won't reverse the wobble.
However, it will definitely shift in the correction direction, so my view is that,
if possible, using an asymmetrical rim on the front wheel of a disc brake front hub is worth doing.
For the rear wheel, even with a disc brake hub,
the freewheel side has the narrower flange width, so
↑using the offset rim in the normal way is the correct approach.
If only there were 24H or 28H disc brake-specific hubs available
(the rear overlock nut dimension is 135mm),
but they're hard to come by.
The 960-series XTRA 965 hub came in 36, 32, 28, and 24H configurations,
the 970-series XTRA 975 hub in 36, 32, and 28H,
but the current 985 hub only comes in 32H.
Soul Cycles and Chris King do offer 28H (for six-bolt rotors)
from a catalog standpoint (though dealer stock is another matter).
But the price is astronomical.
Since building a cyclocross wheel is ultimately an adaptation,
and "hand-built MTB 28H rim wheels" is such a niche market,
it makes sense that hubs for that purpose are scarce too.
Hmm, quite the dilemma.