Have you noticed your favorite bike brands offering bikes for those with Paris Roubaix on their racing schedules? Got one of these bikes?

"That's silly!" you might say. "I could never enter, let alone race, Paris Roubaix! My A-race is Liege-Bastogne-Liege!"

What is it with all the road bikes made for the cobbles? "Welcome to a new class of race bike," says Trek, as it introduces the Domane. It promises, "…blistering speed. Incredible comfort and stability, even on the punishing pavé of Flanders and Roubaix." Booked your flight to Brussels yet?

Specialized segments its road bikes into two verticals: Competitive Road, and Endurance Road. The Roubaix is, of course, in the latter. It's, "the same frame that Tom Boonen rode to win the 2012 Paris-Roubaix."

Cannondale's Synapse offers "exaggerated vibration-absorbing tube shapes" that give it, "13% more vertical deflection." Felt's Z Series promises, "the compliance and fit necessary to make even the longest ride enjoyable." The Z Series emphasizes "vibration damping… to reduce fatigue. These ride characteristics are central to the design goals of the Z."

Felt's text for its Z references Gran Fondos, and BMC's entry into this geometry style is called the Gran Fondo (this pretty bike — well, part of it — is pictured above). The Specialized Roubaix, is the bike for, "enthusiast road riders [who] participate in weekend club rides, Gran Fondos, and occasional races." Really? If I race occasionally I'm good with a Roubaix and 10mm of spacers under my stem, but if I race fast and frequently I'm better off on a Tarmac, with 35mm of spacers under the stem?

It isn't just Trek, Specialized, Felt, BMC and Cannondale that offer both traditional race and newer geometries featuring taller head tubes and narrower cockpits (models built with, per size, more Stack and less Reach). Giant's Defy, Cervelo's R series, and many others do as well. In fact, in my opinion all relevant companies making performance road bikes are now in one of two categories: those that offer this newer geometry, and those that will offer it.

It's the Stacktennial, and today the problem I'm addressing is not technical, rather it's narrative. Hang with me here.

I think you and I agree that we all have a set of fit coordinates that match our morphologies, pedaling dynamics, riding styles. Our saddles are positioned at a certain height, and they are set back some distance behind the bottom bracket. We each have a "cockpit" distance that would describe the length of our bike position, and that length might be defined as the distance from the saddle to the handlebar's "tops", or maybe as the distance from the saddle to the hoods. That handlebar sits some distance below the saddle. These metrics, along with handlebar width and the preferred drop of our road bar hooks pretty well describe our bike positions, and your position is not fungible. It's part of our bicycle DNA. It follows you around from bike to bike.

Now, it's true that if you earned your living riding flat criteriums only – or if you earned your living as a leadout man for your team's sprinter – yes, your saddle (in fact, your whole cockpit) would be a slight bit further forward and your handlebar a slight bit lower. In other words, you'd be riding criterium geometry instead of road geometry. However, most of us don't fit that description.

Most top bike racers don't fit that description either. And that's why Trek has, over the past half-decade, moved from saying its H1 geometry is its go-to high-end geometry to touting H2. What used to be Trek's weekender geometry is now described this way: "It's the right way to get most riders, including many of our Pro Team riders, in the right place. With no need for high-rise stems or spacer stacks, the look is nothing but pro."

Yes! Absolutely right! However, I think Trek is still conflicted. It refers to H1 geometry as, "for athletes with extraordinary range of pelvic rotation, superior core stability, and the desire to get low and aero."

So, H2 is for those without pelvic rotation, superior core stability, and the desire to get low? What if I'm morphologically disposed toward a longer leg and shorter torso? My longer legs prop the saddle up in the air, and the bike's head tube must follow (requiring the head tube to grow taller). My short torso pulls the head tube back toward the bottom bracket. Hence, my morphology – not my lack of core strength, my lack of pelvic rotation, or my lack of any desire to get low and aero – informs my ideal bike geometry. I'm really built for H2, even if I embody all those imperatives that define me as a perfect match for H1.

The image above demonstrates this. Note how the head tube of the green frame is pulled back slightly toward the bottom bracket than that of the mustard frame, and sits taller above it. This represents, very roughly, the difference between Trek's H1 geometry and it's H2 geometry; or between H2 and H3; or between the Specialized Tarmac versus Roubaix; or Felt F series and AR series; or Felt AR series to Z series. You get the point.

I once fit a pro national champion to his bike who had a saddle height (BB to saddle top) of 92cm. Yes, he was tall, at 6'4", but 92cm was still a ridiculously tall saddle height. He was all legs. Did he lack for pelvic rotation? No. Did he need a position that placed less strain on his back and neck that did his teammates? No. And he didn't ride the Spring Classics! Nevertheless, he was really made for Trek's H3 geometry (featured in its Domane). Just because of his morphology. Yes, this is the same H3 geometry that not too long ago was really confined to Trek's women's bikes.

Trek – while I think it's had a difficult time finding the right way to describe its evolution away from H1-as-pro, and toward H2 and even H3 geometries for its high-performance customers – is doing it right. It's manufacturing its highest performance bikes in these newer, alternate geometries. Some companies aren't just acceding to these geometries, they're absolutely embracing them. When Cervelo had to make a decision what to do, geometrically, with its new aero road bike, it abandoned its S3 geometry and ran full speed toward its R series geometry. The S5 may seem a cousin to the downstreamed S2, but it's not. It's geometrically akin to the taller-head-tubed, narrow-cockpitted R3. I get the distinct feeling Cervelo thinks it sees the future, and that future is away from "aggressive" geometries that almost invariably end up with a tall stack of spacers under the stem when the bike leaves the showroom floor.

Which brings me circling back to "my" bike choices, which do not depend on whether I'm riding cobbles, chip-and-seal macadam, or smooth-as-glass pavement. Do I really raise my handlebars 20mm or 30mm when I race on a rough road, and drop them 30mm back down when I race a smooth one? Do you? Or is your bike fit determined by your morphology, and is it pretty similar regardless of the road surface, or whether you're riding 30 hard miles or 70 hard miles? I think I know your answer.

I therefore wish bike companies would simply admit the obvious: these new bike geometries are not for rough road surfaces. Here's BikeRadar's Ben Delaney quoting Trek team liaison Jordan Roessingh about why Chris Horner (and 5 other Shack riders) chose H2 geometries over H1: "It is a lot about cosmetics, but it is also structurally stronger not having a big stack of spacers beneath the stem."

Yes! This was Chris Horner's genius: he thought 35mm of spacers under his stem was inelegant and inefficient, and he evinced an interest in actually using his road bar's drops position.

I don't know why bike companies are so reticent to acknowledge that strong, flexible riders who race at high levels – along with enthusiasts who wish to emulate them – need bikes of various geometries strictly for morphological reasons. Morphology is not one reason the Roubaix and Domane make sense. It's the only reason!

Thankfully, with each passing season bike companies are less and less likely to insult their customers by maintaining that their lowest geometries are for racers; taller geometries are for weekenders and duffers; and taller yet geometries are for women and men who need compliance (code for men who are wimps or weaklings). That said, there are still a lot of companies that think that Dura Ace is for low geometries, Ultegra for intermediate, and 105 and Tiagra for tall.

The lowest of these "race" or "pro" geometries are not for those who enjoy the ability to rotate their pelvises, and who are interested in racing aero. They're for those who are short-legged and long-torsoed. Your geometric choice isn't – or if it is it shouldn't be – about how flexible you are, how hard-edged you are, how ardent your attachment to cycling, your gender, or how fat your wallet. It's almost entirely a matter of morphology.