on the other hand....
"According to Specialized lead R&D engineer Chris d’Alusio, HTC riders remarked that the Tarmac SL3’s rear stiffness was perfect but that the front end of the bike was overly harsh. In response, Tarmac engineers went with a smaller (and lighter) 1-3/8-inch lower headset bearing on the SL4. (The Tarmac SL3 had a 1.5-inch lower bearing.) The new, shapely King Cobra head tube eliminates the flat sides of the head tube that could flex and replaced them with separated bulges to maintain rigidity despite the reduction in bearing size. By elevating the fork crown bearing race higher on the steering tube to bring the bearing more in line with the down tube, the engineering team could also trim material off of the back of the fork crown, making the fork ride less harshly while at the same time reducing weight-adding and strength-robbing bends in its carbon fibers."
different bikes but still

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WW Velocipedist Gargantuan

Interesting, thanks for the info!



1 3/8... another headset standard

1 3/8 has been used prior to Specilialized choosing it, I believe by Cervelo. They came to almost the exact same conclusion as Spec, 1 1/2 is stiff but too harsh.

Meanwhile the Cannondale Supersix continues to ride like a dream, handle superbly and descend with confidence.

Most different standards are there to make the customer THINK they need it - Cervelo just had to adopt ideas pioneered by competitors whilst pretending they were making improvements.

Pure marketing BS to me. It makes me laugh. The Cervelo S2 deforms more in the rear triangle and twists more at the headtube than a simple Seven Alaris. Without a bottle it's less aerodynamic than an R5 with one and it's BB is less stiff than many a welded frameset. Most people I speak to think it will make them faster because it's so stiff and aero. Chalk up one victory for the marketing men.