I designed this support to fit my Specialized Stumpjumper 75mm stem. Thanx to 2015.06.03 shape revision, it now probably fits even (few millimiters) shorter stems. On stems of different brands... sorry, can't tell ... but I guess it could fit too (lower support radius is 19 mm - I use a piece of air chamber between support and stem) Please consider it costed me several attempts and some time to reach final, shared, result; so, please, be nice with critics :-) Please enjoy my design and don't forget to wear helmet while riding your mtb ;-) Updates: 03.06.2015 Update. It works great on my bike !Please go with ABS (PLA is too easy to break). Some poerative suggestions (but you may find your own also): I designed it in two parts because it will be easier to replace the upper slide in case of crash or in case the elastic arm would break with normal use. Re-printing just upper piece will be easier and less time-consuming than printing all the structure.