The world is full of amazing tubes. When I was a kid people talked about test tube babies a lot. You would need great tubes for that. You’d also apparently want a better term for the resulting human. Orchestrally speaking, you’ve got the tuba, which is an amazing tube that emits highly musical farts. And then, of course, bicycles are made of tubes, a whole collection of them, but none regards itself as highly as the top tube.
The top tube runs from the head tube to the seat tube (The shin bone’s connected to the…knee bone.). It is quite literally the top tube, geometrically if not qualitatively. The down tube quietly suspects it’s more important, and the seat tube wonders where you’d sit without it (hello Soft Ride!), but the top tube remains, there, at the top. What else would you call it?
Despite their status, top tubes wonder what we want from them. For years, they went about their roughly level business, and then we said we wanted a frame that was as stiff as possible, so the top tube dropped down to form a compact triangle (complicating bike sizing beyond most riders’ understanding), which is the stiffest configuration possible. But we got one look at that, and then said we wanted a level top tube, because it looks better after all.
Levelness > Stiffness, apparently. Also, style > substance. Prove me wrong.
The top tube does an important job, but also presents a significant risk to the rider, many sudden stops being punctuated by high-speed collisions between sensitive spots and high-modulus carbon fiber or hydro-formed 6061 aluminum. I wonder if the folks who came up with the term ‘credit carding’ for the misfortune of slamming one’s nether bits on their top tube had ever seen the old-timey credit card machines with the carbon paper and their almost violent “CHUNK-CHUNK” sound.
Yeah. I bet they had.
Should we all be riding mixtes? Are they both stiffer AND safer? Or step-thrus even? The mind capers to imagine the entire pro peloton snaking its way up Alpe d’Huez on step-thrus. I’d pay money to watch that, and you would too.
The thing about the top tube is it’s not any more important than any other tube. It’s not even the hypotenuse of the triangle for crying out loud, not to mention the fact that the triangle is almost always, actually, a rhombus, but we’re splitting hairs now. As always with the bike (and these reviews) when you try to make meaning of a single element, in isolation, you end up with not very much, certainly not a test tube baby (now known as an in vitro fertilization), and likely not even a musical fart.