Continuing from last time.
I built a front wheel with the WTB i23 ASYM (asymmetric = offset rim).
HB-CX75 28H, all-Campagnolo reversed Italian lacing.
I'm building the front wheel with an offset rim, but since the disc hub has dish, theoretically it works out if you offset the rim holes toward the opposite side of the rotor mount.
You can also think of it as treating the rotor mount like a freewheel body and doing 4-cross Italian lacing, then flipping it over.
The photo is shot quite deliberately, but the point is: the closer the rim holes are to directly below the hub shell center, the less dish there is. In reality, the offset amount of the rim is smaller than the dish amount, but if the rim holes were directly below the hub shell center, you shouldn't use asymmetrical lacing or anything like that. You can feel when the offset rim is working while you're building.
Since the dish is smaller than on a rear hub, if I incorporate extreme left-right differences like reversed semi-champion or reversed semi-strong lacing, there's a possibility that spoke tension could reverse (the rotor mount side becoming lower in tension).
Together with the XT hub 32H front wheel from the other day, I now have a pair of front wheels instead of a front-and-rear pair. In terms of wheel-building dimensions, these XT and CX75 hubs are basically the same hub, but the CX75 is only available in 28H while the XT is only 32H.
With Shimano hubs of this type,
spoke length becomes 4 types, but if the hub, rim, and lacing pattern are the same, front right and rear left, and front left and rear right, end up being roughly the same length. Both front and rear wheels can be 6-cross or 4-cross of course, but since I do front wheel as 6-on-4 and rear wheel as 4-on-6 with this hub, front right and rear left are both 6-cross laced while front left and rear right are both 4-cross laced, so they match up at nearly the same length.
Strictly speaking, front right and rear left differ by about 1mm, so if I prepare spokes in 0.5mm increments I can share them between wheels.
However, in this case the front wheel is 28H, so the spoke lengths for 4-cross and 6-cross are different from 32H, and spoke length clearly becomes 4 distinct types.
But here's the thing—all that talk above assumed "same rim." I found that if the front rim is KOM and the rear rim is ASYM, the difference in rim inner diameter meshes nicely and spoke length comes out to just 2 types. However, in this case the KOM is 32H (rear rim) and the ASYM is 28H (front rim), so I can't benefit from that coincidence. Daaaaamn!
Since I'd researched this much beforehand, I'm cutting fresh spokes for the ASYM front wheel. That's why I managed to shoot a photo with two front wheels.
So the ASYM and CX75 spoke lengths are types G and H in the diagram above, but the KOM and XT front wheel spoke lengths should be pretty much types E and F, so I've already confirmed that they can be reused as F and E for the XT rear hub.
I disassembled the front wheel.
I transplanted the front left inpoke spokes as rear right inpoke spokes.
↑ inpoke
I transplanted the front left outpoke spokes as rear right outpoke spokes.
↑ outpoke
Similarly, I transplanted the front right outpoke spokes as rear left outpoke spokes.
Since I'm doing JIS lacing, if it were same-side lacing it'd be right-drop, but since I'm doing 4-on-6 it's left-drop. For front right → rear left, the spoke length differs by about 0.5mm, but I reused them as-is. When I looked at it after building, the nipple and spoke end face were flush, so there's no issue with the length.
Built.
FH-M8000 32H, all-Campagnolo 4-on-6 JIS lacing. No lacing nipples per request, and I built it with brass nipples.
I built a front wheel with the WTB i23 ASYM (asymmetric = offset rim).
HB-CX75 28H, all-Campagnolo reversed Italian lacing.
I'm building the front wheel with an offset rim, but since the disc hub has dish, theoretically it works out if you offset the rim holes toward the opposite side of the rotor mount.
You can also think of it as treating the rotor mount like a freewheel body and doing 4-cross Italian lacing, then flipping it over.
The photo is shot quite deliberately, but the point is: the closer the rim holes are to directly below the hub shell center, the less dish there is. In reality, the offset amount of the rim is smaller than the dish amount, but if the rim holes were directly below the hub shell center, you shouldn't use asymmetrical lacing or anything like that. You can feel when the offset rim is working while you're building.
Since the dish is smaller than on a rear hub, if I incorporate extreme left-right differences like reversed semi-champion or reversed semi-strong lacing, there's a possibility that spoke tension could reverse (the rotor mount side becoming lower in tension).
Together with the XT hub 32H front wheel from the other day, I now have a pair of front wheels instead of a front-and-rear pair. In terms of wheel-building dimensions, these XT and CX75 hubs are basically the same hub, but the CX75 is only available in 28H while the XT is only 32H.
With Shimano hubs of this type,
spoke length becomes 4 types, but if the hub, rim, and lacing pattern are the same, front right and rear left, and front left and rear right, end up being roughly the same length. Both front and rear wheels can be 6-cross or 4-cross of course, but since I do front wheel as 6-on-4 and rear wheel as 4-on-6 with this hub, front right and rear left are both 6-cross laced while front left and rear right are both 4-cross laced, so they match up at nearly the same length.
Strictly speaking, front right and rear left differ by about 1mm, so if I prepare spokes in 0.5mm increments I can share them between wheels.
However, in this case the front wheel is 28H, so the spoke lengths for 4-cross and 6-cross are different from 32H, and spoke length clearly becomes 4 distinct types.
But here's the thing—all that talk above assumed "same rim." I found that if the front rim is KOM and the rear rim is ASYM, the difference in rim inner diameter meshes nicely and spoke length comes out to just 2 types. However, in this case the KOM is 32H (rear rim) and the ASYM is 28H (front rim), so I can't benefit from that coincidence. Daaaaamn!
Since I'd researched this much beforehand, I'm cutting fresh spokes for the ASYM front wheel. That's why I managed to shoot a photo with two front wheels.
So the ASYM and CX75 spoke lengths are types G and H in the diagram above, but the KOM and XT front wheel spoke lengths should be pretty much types E and F, so I've already confirmed that they can be reused as F and E for the XT rear hub.
I disassembled the front wheel.
I transplanted the front left inpoke spokes as rear right inpoke spokes.
↑ inpoke
I transplanted the front left outpoke spokes as rear right outpoke spokes.
↑ outpoke
Similarly, I transplanted the front right outpoke spokes as rear left outpoke spokes.
Since I'm doing JIS lacing, if it were same-side lacing it'd be right-drop, but since I'm doing 4-on-6 it's left-drop. For front right → rear left, the spoke length differs by about 0.5mm, but I reused them as-is. When I looked at it after building, the nipple and spoke end face were flush, so there's no issue with the length.
Built.
FH-M8000 32H, all-Campagnolo 4-on-6 JIS lacing. No lacing nipples per request, and I built it with brass nipples.