There are precious few bikes with rear wheel cutouts which preserve this feature in their 650c designs. There are fewer companies yet which offer this will maintaining a chainstay length that guarantees smooth, minimal-friction drive trains. Felt is one that does.

The DA and the B2 are geometrically and, in terms of their shapes, the same frame. The most obvious frameset difference is in the fork spec'd with each model. Geometrically, we can speak of these frames as one, and what follows is for both these models.

Felt does exactly what Cervelo does with its carbon bikes, in that it produces a seat post with a fore and aft position, but the framesets are built around the idea of the forward position being used (as in the case at left). Both Felt and Cervelo offer two geometries on their charts, based on which seat post position you choose. If one considers the way these bikes were designed, we can pretty much ignore the geometry in the aft position, and we will -- most of the time.

But not this time; not with these sizes. This is because Felt's smallest two sizes -- both built with 650c wheels -- are built with the fore and aft position being "steep" and "ultra steep." In the 48cm size, the two seat angles offered are 78 and 80 degrees, depending on whether the saddle is positioned fore or aft. Really, either is acceptable, but it's wise of Felt to do it this way, because the dirty little secret is how many triathletes really do ride at about 80 degrees.

The top tube lengths are 47.3cm and 49cm respectively, depending upon whether your saddle is in the fore or aft position. This is fabulous! Why? Because very few bikes are made that offer a 47cm top tube, and many, many women need a top tube of this length for their tri bikes.

Where is this bike in this 47cm size lacking? The head tube is 11.5cm tall, and this makes it 4cm taller than the Kestrel's Airfoil Pro. This may or may not be a problem, depending on how low you need to be in front. Otherwise, the geometry and features in this 48cm bike are almost unsurpassed.

The 51cm version of this bike is also built atop 650c wheels, and this is a blessing for the slightly taller rider who likes the nimble handling of these wheels.

The aluminum versions of these bikes -- the S32 and S22 -- share the geometries of their carbon cousins. The one difference between them is that the aluminum bikes (S32 and S22) do not have the faired rear wheel in their 650c-wheeled sizes that they do in their 700c sizes while, as mentioned above, the B2 and DA do maintain the faired rear wheel and a 38-ish chain stay regardless of wheelsize.

This means that these geometries can be had for prices from $1300 to $7500. For the rider shorter than 5'6", Felt has been geometrically thoughtful of you, and its bikes are high on the list of consideration. Read more about Felt's tri bikes here.