Several of the upper tier Box bottom brackets were engineered using Box Oversized Technology. These were developed in concert with the crank sets. We all know that there is no use pushing hard on your pedals if you canâÂÂt deliver most of that power to the rear wheel. During the creation of our bottom brackets Box were obsessed with Power delivery / pedalling stiffness. To reduce lateral deflection, we chose to oversize the bottom bracket and therefore subsequently enlarged the spindle and the crank armâÂÂs interfaces. This made room for larger bearing rings contributing to a vast increase in contact area. Box removed material from unloaded sections to reinforce the zones of high stress. Not only are you going to be more efficient with power delivery, but youâÂÂll also feel the instant response of acceleration. Seen through another lens, less energy will be required to achieve the same elapsed time.Key differences: The Box Two M30 bottom bracket is a slightly less acute embodiment of our Oversized technology seen in the M35. Generously sized ABEC-5 bearings help reduce power loss to defection. The larger 30mm cross section is designed to mate up with the rest of the M30 line of Oversized crank sets.
