2 of 2: RaceFace cinch spindle length guides showing the most common RF136 spindle having an end-to-end length of 136.5mm which is ideally installed into a 98.1-100.1mm OAL bottom bracket spacing (±1.0mm).
***Please Note: A 2022 Rocky Mountain Blizzard A10 fatbike, when converted to RF threaded BSA bottom bracket (c/w Ø30mm spindle bore+bearings), will fit the narrower RF169 (= 169.5mm) spindle size. There's no need to use the two slightly longer spindle lengths on a MEDIUM sized frame for up to size 11 US feet/shoes.