Two of the brands shown here, WTB and PowerTap, announced their new products just before the Taipei Cycle Show, so we used our time with them to take a few detailed shots and ask more technical questions (of WTB anyway).
WTB’s products were announced just days prior to the show, but all have availability dates this summer. The rims have an interesting production story. They say they’re still playing around with different materials in different places and different manufacturing partners based on where the rims are going to be sold.
The 27.5 rim shown here has a more UD finish (left) on the inside and it’s made in Taiwan. The 29er has the woven top layer and is being made in China. Apples to apples, it’s coming out lighter, hence the eerily close claimed weights for different size rims. They’re still in testing, but Chris Feucht, product development manager, says all aftermarket rims will likely ship from the China factory and that the 27.5″ is likely to see a weight reduction by the time they’re available. The Taiwanese made rims will likely be reserved for OEM customers. So, build your own wheels and they’ll probably be lighter.
The reason for the difference is basically just dealing with the different capabilities and methods used by different manufacturers.