M 1900 275 mtb wheelset f 15x100 r 12x142 swiss engineering in an outstanding value package the 1900 series wheels are a fantastic option for those looking to upgrade without breaking the bank m mountain versions use a 225 mm internal 27 mm external width pinned rim to give additional support to wider tyres whilst avoid excess weight that would compromise the m 1900s all day abilities with an average weight per pair of 1855 grams in 275 the m 1900 splines are some of the lightest wid