The Trek Skye SL is a mid-range women's mountain bike and is the next level up from the lower-end Trek Skye S. The Skye SL is different from the Skye S in a number of ways: frame size options are different at 14, 16 and 18" instead of 13, 16 and 19.5"; the Skye SL has a WSD Alpha Black Aluminum frame with a semi-integrated head tube, formed down tube with an integrated gusset, formed top tube, monostay seatstay, forged dropouts with a rack and fender mounts and a replaceable derailleur hanger; Wellgo alloy platform pedals rather than nylon and; a larger 100mm RST Gila TnL front suspension.