OP mentions picking up a new bike. If regarding a new custom (and not compact frame geo), no doubt would want near exact fitment.
But for for old bikes, 56cm tt is my preferred but not picky nor stuck on it. I can make 2 cm + / - in frame size work. That's why they make different stems, post and bar width. And the heck with aestetics, I want to ride it and if one is concerned about that, just temporary change it for show or photo op's. No biggie.
Kind of funny topic though. In the 1970's bike boon, fairly common that bike shops pushed whatever size bikes in stock with not much concern of a buyers height or fit. When I acquired my Fuji, the dealer was pushing much too large of a frame even though my plans were for distance touring. I ended buying a like new prior model year trade in for nearly the same amount as a brand new same model. Didn't have much of choice as they were a hot commodity.
Originally Posted by
Dave Cutter
I like a 56.
But I've found that when I use 42cm wide handlebars a 55 bike can be comfortable. Unsurprisingly... a 57 with 44cm bars feels huge (although very rideable). I think sometimes people forget how much bar width affects the feeling of being stretched.
Indeed.
By changing the width of a bar, it feels like a different bike and size.
I enjoy riding back woods trails, single track and gravel grinding on a road bike. I get it that the majority would prefer to be on a 29er and bust the route but for me a 700c X wide width tire, drop bar is fine. Almost cyclo-cross like.
Though I do like width in a more technical, rough terrain. I don't think it really changes in how the bike handles or weight distribution but the little extra leverage gives me a secure feeling. Lately, I've been playing with an early 70's LeChampion with a narrow bar but I custom flared the drop portion only. Not quite a Midge version or a rando bend. Nice and comfy for the wrist, (especially after a motocross incident from many years ago and an ache reminder). Can get down and dirty on the fast gravel yet keep the mass low while torqueing up in the ruts.
So now with the flared bar, I'm considering using a slight shorter stem. Surely is less aero but I'm not racing or against the clock.