How to Raise Bicycle Handlebars. Part of the series: Bicycle Repair. In order to raise a bicycle handlebar stem, first determine the size of wrench that is needed to loosen the bolt holding the stem in place. Determine a comfortable handlebar height with help from an experienced bicycle mechanic in this free repair video on raising bike handlebars. Read more: http://www.ehow.com/video_5773308_raise-bicycle-handlebars.html