When you talk about this company -- and this is especially true when you're talking about geometry -- it's really a pair of discussions you're having, and really three discussions in a way.

There are the carbon bikes, that is, the Lucero, the Caliente (at right) and the Seduza. Then there are the more entry-priced aluminum Kilo and Tequilo, which are geometrically distinct from the carbon bikes. Finally there is the TiPhoon, a terrific and robust entre into the custom milieu, but again geometrically distinct because it has no geometry until you give it one.

So, when considering the world as it is for those who ride bikes under 50cm, what is QR offering?

The carbon bikes come in T-shirt sizes. It's the XS we're interested in. This conforms to everybody else's 47cm or 48cm sizes. As is the case with Cervelo, Felt and Kestrel (to name three) the XS in these three QR carbon models is made with 650c wheels and comes with a 78 degree seat angle. The top tube is 49cm -- similar to these other brands' small bikes -- and has a 10cm head tube. This is taller than the 7.6cm we find in Kestrel's Airfoil Pro, and it's shorter than Felt's 11.5cm we find in all its tri bikes. 10cm is a very good size for most riders between, say, 5'5" and 5'6", and if you're 5'4" it's also pretty good. But if you're 5'3" or shorter, that might be too much head tube and it might again be the Kestrel you're looking at.

Except QR does one thing to mitigate this, and in describing it we'll make this a little more confusing for you, because that's (unfortunately) sometimes the sort of folks we are. The QR has a bottom bracket drop of 4.0cm, as opposed to 4.5cm in the Felt and the Kestrel. This means the QR has a "normalized" head tube height that's a little shorter relative to the other bikes mentioned or, to put it another way, its "stack" is 5mm shorter. In other words, the QR will fit somebody just that little bit shorter, and as a result its gemoetry in this size is closer to the Kestrel than it is to the Felt.

Now, about that chain stay. It appears QR has engineered in one direction, and Cervelo in another. At least that's what it seems considering the posture each has taken toward its designs. QR's chain stay length is 38.4cm, and that's it for each of its carbon bikes, whether built around 700c wheels or 650c wheels. This means that the front of the rear tire sits a few centimeters behind the seat tube versus that place the 700c tire resides on the taller sizes. And that means the size XS in the Seduza, Caliente, etc., does not have the faired rear wheel. QR apparently views that chain stay length -- and its attendant shifting and drivetrain friction issues -- to be the predominent concern it chooses to address. Cervelo's carbon bikes have 38cm chain stays in 700c and 36.8cm in 650c. But the Cervelo's 650c sizes have faired rear wheels. Cervelo, then, considers the aerodynamics of the faired rear wheel to override any concerns generated by the shorter chain stay. The customer must make a stylistic choice between the two design theories.

At $3000, $4000, and $4800 respectively the Seduza, Caliente and Lucero are aggressively spec'd and priced bikes, and the geometry of the XS size is supremely well suited for smaller riders.

The aluminum Kilo (at left) and Tequilo, at $1900 and $2400 respectively, are ever so slightly better designed for the smaller riders. The head tubes of these frames are 9cm in the XS size, also termed 46cm, which would seem to indicate that you can get 1cm lower on the Tequilo than you can on the Seduza. But the Kilo/Tequilo's bottom bracket is set 8mm closer to the ground, which means the "stack" dimension of all these QR frames in size XS is very close to the same. But, because the Kilo/Tequilo sits a bit closer to the ground, the bike on paper ought to corner and handle that slight bit better than their carbon analogs.

The top tube in the XS size is 47cm off a 78.5 degree seat angle, which makes these twin QR models among the shortest of all tri bikes as expressed in the bike's "reach" (the horizontal distance between the bottom bracket and the top of the head tube).

In keeping with QR's preference for a chain stay length shorter than which it will not go, the XS size in these aluminum bikes is 38cm. This means the faired rear wheel is not evident, as it is in the 700c-wheeled sizes.

As the bike sizes grow taller and taller, the geometries of the Kilo and Tequilo diverge quite a bit from the carbon QR models. But in this smallest size, as you can see, the stack, reach, and seat angles are quite similar. They all work very nicely for the shorter rider, and anyone 5'3" and up will find these QRs in XS eminently rideable, and even those a little shorter can probably get them to fit reasonably well.

On paper, you'd think that the best fit of all among the bikes in the QR line would be the TiPhoon, because it's made custom. But there is a built-in limit to the TiPhoon's head tube height, which is 10cm, and that is with an external headset. This means the bike's minimum stack is 2cm greater than the stack available on any of the other QR models. For this reason the TiPhoon, which remains arguably the preeminent custom option for triathletes today, probably does not equal the value of its carbon stablemates for those 5'6" and shorter who need a low front end. Read more about Quintana Roo's tri bikes here.