Mocking up my folding Twenty as a touring bicycle with drop handlebars. I need a longer stem. I am going by "French Fit" on a fit calculator, which says that I need a bicycle with a 58cm top tube and an 11 or 12 cm stem. The Twenty has an effective top tube of about 56.5cm and even though I do not usually ride bicycles with drop handlebars I do feel cramped for length on this one. The existing stem gives about 5cm reach.