ZIPP VUMA CHRONO CRANKSET. Crank Length: 177.5 mm Chainring Size: 53T/39T Zipp Vuma Chrono Crankset 172.5mm x 53/39T 9 seconds over 40 kilometers. Zipp's VumaChrono is simply that much faster than other aero cranksets. Compared to traditional cranksets, the savings can exceed 25 seconds. To create its distinctive monocoque dome and airfoil arms, manufacturing each VumaChrono requires over 100 steps and takes an experienced worker almost half a day. The breakthrough shape and a massive 30mm aluminum spindle make the VumaChrono by far the stiffest crankset we’ve ever tested while keeping its assembled weight to just 860g including the bottom bracket (177.5mm, 53/39). (bottom bracket not included) The VumaChrono has a unique, spider-less design with outer chainring held in place by 9 screws around the perimeter of the carbon face. The inner chainring has its own set of bolts, making the VumaChrono the first crank intended to accommodate both single and double chainring setups. The VumaChrono has an ultra-narrow 146mm Q-factor. It includes an installation tool made by Pedro’s. A spacer kit is available for compatibility with the BB30 bottom bracket standard. Length 177.5mm Assembled Weight 860g (53/39) Chainrings 54/42 BCD Custom Q-factor 146mm Reference: ZPCS20201 Brand: Zipp