If you have a 2016 or 2017 Salsa Mukluk Carbon frame in large or XL ... We have confirmed the Wren 100 ATK is a direct bolt-on compatible suspension fork upgrade! Your stock wheelset and headset will work ... Plus there will be clearance on the downtube ... And your warranty wont void. ** note this works on the carbon mukluk frames ** cannot confirm clearance on the alloy frames as Salsa says they are a bit differently spaced. ** So if you tried a Mastodon Pro and it didnt have clearance ... The Wren ATK is the way to go. Cheers !!