The asymmetrical rim shape means that the spokes hole and rim shape are offset from the center line. This helps to even the spoke tension between drive side and non-drive side, while, at the same time, allowing for more equal spoke angles and spoke length in the build.
The asymmetric design can insure the rims weight center point is in the central, build up into stiffer, stronger and more reliable wheels by improving the bracing angles of a dished wheel and equalizing the spoke tensions between the drive and non-drive side spokes.
Using an asymmetric rim results in a stronger, stiffer, and more reliable wheel build when compared to a standard rim.
So the asymmetric carbon rims for mountain bike can improve the chain-side weight, and make MTB riding more smoothly and faster.
If you look at the spoke bed of a low-profile Bontrager rear road wheel (like the Race X Lite or Race Lite), you'll notice that the spokes don't join the rim at the center. Rather, they're shifted slightly toward the non-drive side. Bontrager calls this design feature OSB, or Offset Spoke Bed. And here's why we do it.
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