Comparative geometry analysis

Frame and Wheel knows that the month of November is the best time to talk to independent bike store owners: the weather is cooler, customers are slipping into hibernation and new inventory for 2011 has not yet arrived. IBS owners provide Frame and Wheel with good information and guidance about how things work, and what does not work, and provide Frame and Wheel with important anecdotes about IBS life.

One IBS mentioned to Frame and Wheel that the geometry of a frame determines the target market. For example, a traditional racing geometry is characterized by steep head tube angles and steep seat tube angles, a short wheelbase and a short head tube. These features make for aerodynamic positioning of the rider on the bike with more weight on the handle bars (and nose closer to the stem); a responsive  or a "twitchy" ride, where the bike turns the moment the rider turns his head, and a "rougher" ride or a ride that is less comfortable over long distances because the bike is not absorbing the shocks in the road, but delivering it straight to the rider. The traditional road racing geometry offers a seat tube angle of between 72 and 75 degrees and head tube angles range from 72 to 75 degrees. The steeper the angles or closer to 75 degrees, the more responsive and twitchy the ride; the slacker the angle or the closer to 70 degrees, the more stable and comfortable the ride. Additionally, the shorter the wheelbase, the more responsive the ride (the rider always has to steer the bicycle); the longer the wheel base the more stable (the bicycle will more readily steer itself).

Comparative geometry analysis

Brand	Austro-Daimler	Cervelo	Cervelo	Felt	Felt
Model	2011 Superleicht	2011 S2	2011 RS	2011 Z2	2011 F1
Frameset MSRP	$2,500	$2,800	$2,600	n/a	$3,500
Size	47	48	51	51	48
Seat tube (C-T)	47.0	47.0 *	50.0 *	47.0	44.0
Top tube (effective)	51.5	51.5	53.2	52.5	51.0
Head tube length	10.5	10.0	14.0	14.0	10.0
Chain stay length	41.0	39.9	41.0	41.7	40.3
Front center	57.2	54.7	58.8	58.4	57.7
Wheelbase	97.3	95.0 *	97.3 *	99.1	96.9
Head tube angle ⁰	71.0	72.5	71.0	72.0	71.0
Seat tube angle ⁰	74.5	73.0	73.0	74.5	74.5
Bottom bracket drop	68.0	68.0	68.0	70.0	72.0
Stack	50.1	50.2	53.1	54.1	50.0
Reach	36.0	36.1	36.9	37.4	37.0
Stand over	n//a	70.9	74.2	72.9	68.1
Trail	n//a	n/a	n/a	n/a	n/a
Bottom bracket height	n//a	n/a	n/a	n/a	n/a
Fork rake	4.5	4.3	4.0	5.0	5.2

The Cervelo S2 has a steep seat tube angle (73 degrees), a steep head tube angle (72.5 degrees) and a short wheelbase 96 cm). This makes for a responsive ride and positions the rider aerodynamically on the bike. The Cervelo RS has an identical seat tube angle (73 degrees), but a slacker head tube angle (71 degrees) and a longer wheel base. The head tube is also much taller (14 cm compared to 10 cm on the S2). This makes for a more stable ride and allows the rider to be positioned more comfortably (less aerodynamic) on the bike. Meanwhile, the Felt F1 has a steep seat tube angle (74.5 degrees), a slack head tube angle (71 degrees) and a short wheelbase (96.9 cm). Presumably, the ride on this bike is closer to stable and comfortable. By contrast, the Felt Z2 has an identical seat tube angle (74.5 degrees), a steeper head tube angle (72 degrees), a longer wheelbase (99.1 cm), and a taller head tube (14 cm compared to 10 cm on the F1). This makes for a more stable and comfortable ride and also allows the rider to be positioned less aerodynamically on the bike.

The Austro-Daimler Superleicht has a steep seat tube angle (74.5 degrees) and a slack head tube angle (71 degrees). The seat tube angle is steeper than the Cervelo S2 and identical to the Felt F1; the head tube angle is more slack than the S2 and identical to the F1. The Superleicht's wheelbase is 97.3 cm. It is longer than the S2 and essentially the same as the F1. The Superleicht's head tube length is 10 cm and it is essentially the same as the S2 and the Felt F1. The Superleicht is a racing geometry frame, which means that its target market is the racing market, rather than the enthusiast market; however, its geometry is not as aggressive as the S2, which means that its ride and handling characteristics are more stable and comfortable. In terms of price, the Superleicht is positioned at the low end of the premium market.