Several comments have been made about advantages of wheels which are more U-shaped than V-shaped and have a wider spacing between the bike rims. It is a relatively new development.
There are some advantages of this bicycle rim design.
Fisrt, It will have a straighter line and smoother transition from tire sideway to rim edge, for example; also less bulging of tire walls and make for easier passage of an inflated tire through brake calipers.
With standard shaped road bicycle rims, the only design variations generally relate to rim width at the brake track and rim depth, with all other changes moving the road bike rims from a roughly 'V' shape to more of a 'U' shape. With the concept, the maximum width of the rim can be tuned independent of brake track width, while the widest point of the rim may also be moved up or down within the rim cross section.
Xiamen Most Sports Goods Co.,Ltd have 20 molds for U shape carbon rim(23mm or 25mm width),include 24mm,38mm,50mm,60mm,88mm clincher rim and tubular rim ,U shape carbon rim is very popular in China and North America,U-shaped rim its greater strength than V-shaped.
The tire attaches to the prongs of the U. The bottom part of the U is often flat on MTB carbon rims, but can be curved, sometimes even almost pointed, like the bottom of a V. Generally, the more curved or pointed the inner part of the rim is, the more strength it will have.
Wheels offer unmatched aerodynamics across the widest possible range of wind conditions, while having the lowest possible cross wind sensitivity. These shapes are also not affected by tire width changes nearly to the effect that other ‘V’ and ‘U’ shaped rims are, allowing the athlete to choose the optimum tire for his/her event, and not have to compromise on a tire around which the wheel was originally designed, in some cases up to 15 years ago.
Second, these clincher rims are with non-parallel brake track. The non-parallel brake track did not present a problem for braking. In fact, no need to alter the angle of brake pads. And it is nice to have the solid braking performance on an aero road bike wheelset.
The non parallel brake track has been around for a while, it's on Zipp's carbon wheels and some Hed wheels too. This angled brake track will improve the airflow over the tire onto the rim, help toe in the brake pads, and also help to dissipate against heat buildup on the edge of the rim.
The benefit of our new U shaped rims are: adding stiffness, due to a slight widening of the rim, and better braking, with a slightly angled brake track, not grew much in weight. And they are light, fast. when hit a few windy sections, it could not fell a thing in the cross winds.
Xiamen Most Sports Goods Co.,Ltd supply U shaped 23mm width and 25mm width carbon rim,main type of carbon include clincher and tubular carbon rim 24mm ,38mm ,50mm,60mm,88mm.