Originally Posted by
njkayaker
Comparing the geometries of 54 cm S2, R3, and RS.
BK_SZ___WHS____HTA____BB____HTT__HTL__FC___RC___SOH__STK__REA___RK
S2_54___700c___73°____68____545__140__573__399__746__541__380
R3_54___700c___73.1°__68____548__148__575__405__753__555__378
RS_54___700c___72°____68____546__160__590__410__764__555__376___49
RS_51___700c___71°____68____532__140__588__410__742__531__369___53
It's interesting that the slightly longer head tube (160mm or 12 mm longer than the R3) doesn't change the reach by much (just 2 mm).
It would seem that "more upright" (the RS) would mean a significantly shorter reach. Are people supposed to pick the next size smaller RS?
I think more than anything your chart shows two things:
1. Use stack and reach, always.
2. Cervelo went through a change in belief about geometry between the S2/RS production and the new R3 production. Clearly from comparing to the S2(which used to share the R3's geometry), if a person wanted a "relaxed geometry" bike, they could go with the RS and see significantly different stack to reach combinations and different handling characteristics. Now, Cervelo's R3 geometry is "supposedly" built to work for their pros and the everyman. The stack and reach are almost the same, despite head tube length differences, because of the new Cervelo fork's longer Axle to Crown. So one chooses the RS as a comfort bike more because of it's price, tire clearance or slight changes in head angles or wheelbase; not because of a higher handlebar position.
Anyway, I'm starting to see murmurs of the possible "offing" of the RS because of its redundancy in the new Cervelo line up but thats just rumors.