2005 P2K Headset now a 1 1/8

Triathlon Forum
1

I was looking at the cervelo site tonight and saw that the 2005 P2k has a 1 1/8 is this a typo? I thought that Cervelo speced 1 inch for TT bikes and 1 1/8 for road bikes.

http://www.cervelo.com/bikes/2005/P2K.html

**Part ****Ultegra Tri/Time Trial Kit **Fork Wolf TT (more info) Seatpost Cervélo Aero Carbon Shift levers Shimano Dura-Ace Bar-ends Front derailleur Shimano Ultegra 10-speed Rear derailleur Shimano Ultegra 10-speed Cassette Shimano Ultegra 10-speed Chain Shimano Ultegra 10-speed Brake calipers Cervélo Brake levers Dia Compe 188 Crankset FSA Carbon Pro Team Bottom Bracket FSA Platinum Headset Cane Creek IS-2i 1-1/8" Handlebars Visiontech basebar and clip-on Stem Visiontech Sizemore Saddle Cervélo TT special Wheels Velomax Vista Tires Vittoria Diamante Pro Lite

2

Apparently this is NOT a typo:

The 2005 P2K does have a 1 1/8th in steer but the head tube is only 1 mm wider than our 1 inch head tube. It was an upgrade to get better front end stiffness and not have the aerodynamic penalty.

Thank you for your interest in Cervelo.

Sincerely,

Chris, Customer Service

3

if that is true ('05 bigger head tube is within 1 mm of '04 smaller head tube), that is impresseive engineering. i wonder how they did it?

4

The P3 Carbon is also 1 1/8" and it is actually 0.5mm narrower than the 1" P3 SL.

5

What’s the secret to this clever design?

Does this mean you that if you wanted to you could also make a frame with a 1" steerer that would have a head tube that is 0.75" in diameter?!