Our 386 spider system uses a three-armed spider and 86mm bolt circle diameter to deliver an extremely stiff and lightweight crankset. The SL-K Compact 386 has unidirectional carbon fiber arms with a strength-enhancing alloy spine. With a very deep cross-section to the cranks, the spider arms can be very short for stiffness – one of the three mounts is behind the crankarm itself. Four chainring combinations are available, with an optional chain guard for the 39 or 40T outer rings. There’s a choice of BB30 or MegaExo variants.