Similarly to the wheelbase, downtube length is the outcome from the designer’s choices identical as within the length of the head tube, seat tube, and prime tube. Before racing bicycles mounted their shift levers within the down tube. On More moderen versions, they are mounted on handlebars with brake levers. https://bike-engine-details61505.tokka-blog.com/35308102/the-party-bike-klein-roosboom-diaries