ROTOR Chainring Set Q-Rings oval 2-speed BCD 110 mm | 4-Hole for Rotor ALDHU 3D+ | Shimano Road inner Ring The popular oval Q-Rings chainrings for Rotors ultralight ALDHU 3D + aluminum crank. With a bolt circle diameter of 110 millimeters and the asymmetric 4-arm mount , the chainrings are also compatible with the current Shimano Ultegra and Dura Ace cranks . The oval shape of the Q-ring chainrings is used to optimally use the leg muscles and thus increase your own performance! The theory behind this is based on the fact that the leg muscles of humans is primarily designed to stretch the leg, while angling of the leg is required only rarely and without much effort. The corresponding muscle groups are therefore naturally so different pronounced that even with hard training, the performance of different muscle groups can not be matched. For round chainrings, this difference therefore always results in a non-round kick and a significantly faster fatigue of the muscles pulling on pedaling. The Rotor Q-Rings start at this point and, because of their oval shape, put a heavier strain on the squeezing muscles and at the same time relieve the pulling muscles. This concept increases both the sprint and endurance performance through the better use of anatomical conditions! For optimal adjustment of the oval Q-Rings, the OCP system (Optimum Chainring Position) has been further refined. Through a combination of different positions of the crank arms on the crankshaft and a fine-styled Spider recording the position of the chainrings can be adjusted in 1-degree increments. Technical specifications: intended use : Road bike, Triathlon, Gravel Material: 7075 T6 aluminum Technology: OCP system bolt circle diameter : 110 mm Attachment: 4-arm Spider (Shimano asymmetric) Number of teeth: 34, 36, 39, 42 or 44 Assembly: outside Compatibility cranks : Rotor ALDHU | VEGAST | INPOWER | 2INPOWER | Shimano ROAD Compatibility chain: 9-fold, 10-speed or 11-speed Assembly: outside Ovalization: 12.5%, position adjustable in 1 steps Color: Black