Originally Posted by RoadLight

Hi Kontact,

As much as possible bike manufacturers try to distinguish their models from their competitors. There are always exceptions to any generalization when comparing one manufacturer to another. As for Cervélo, they are a small bike manufacturer. Most pros ride bikes made by their bike sponsor so Cervélo is not very common. I've seen more Cervélo triathlon bikes than road bikes. So Cervélo would not be my first choice for these comparisons.

But your point about the cyclist's position is crazy. Of course most frames with a road racing layout can be adapted so a cyclist can use an endurance body orientation. The differences in frame/fork layout are not so extreme as to exclude this. Traditionally, the contact points of a bike (saddle, handlebar, pedals) have allowed great variety which is essential for a good fit. It's too bad that the move to more aggressive aero frames and forks is reducing some of the adjustability.

But let's look at Cervélo since you've cited them as your example. I've taken their three top road bike frames and listed some dimensions below for a 58 cm frame size (the large frame size that fits me best).

Cervélo R5 (classic road frame): head tube length = 178 mm, BB drop = 69.5 mm, top tube length = 581 mm.
Cervélo S5 (aero road frame): head tube length = 181 mm, BB drop = 68 mm, top tube length = 581 mm.
Cervélo C5 (endurance road frame): head tube length = 207 mm, BB drop = 72.5 mm, top tube length = 581 mm.

It should be obvious to all readers that Cervélo gives its C5 endurance road frame a taller head tube plus a greater BB drop than its R5 and S5 frames. Why? The endurance layout favors a more upright and presumably, more comfortable, body orientation for the cyclist. But this results in a less aerodynamic orientation. The R5 and S5 sacrifice a bit of comfort in order to be faster. Being faster usually requires better aerodynamics (the exception being steep climbing).

Finally, when comparing one frame type to another, we should all assume that the default factory-provided stem and handlebar are used and the stem is mounted as low as possible (if headset spacers are used, just one 5 mm spacer). That way we are comparing apples to apples. As Kontact rightly points out, a variety of body orientations can be achieved by manipulating the steering tube length, stem angle and length, handlebar shape, seat post height, etc.

Kind regards, RoadLight