Record 10 speed. No problems whatsoever with it since 2006 so no compelling reason to change. Complete SunTour on my old mountain bike (Davidson "Quick and Dirty" circa 1998). No problems with that, either!

KAC

Every component on my Tarmac is from the Dura Ace 7800 group. Even the crankset, brakes, wheels (scandium 7801), and pedals (7810).

It's truly a full Dura Ace bike. No exceptions. And I like it that way.

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2008 Specialized Tarmac Pro SL2 Team Gerolsteiner w/ full Dura Ace groupset - 16.09 lbs
http://strava.com/athletes/ransom

Chorus 11 speed on best bike (Condor Baracchi carbon, not exactly a weight weenie at c. 17lb)
Chorus 10 spd on Roberts Steel
Centaur 10 spd on Burls TT (steel)
Mix of Chorus and Athena 9spd (Athena 11 cranks) on winter / training bike
XT on One One (Inbred - steel) MTB.

Can't afford to go above Chorus and can't see the point anyway.

I ride with Campagnolo Super Record EPS. Never ever go back to mechanical group. My friend tested my bike and said now shifting is even more fun than pedaling.

Everyone who has driven with EPS group know what I mean. Yes, battery box is like mini cooper or fiat 500 but who cares? Shimano Di2 is good, but EPS is on the another level.

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Team KAS-RAK: http://www.pellossalo.fi/pellossalonnousu/
My Look 695 SR + EPS : http://www.pellossalo.fi/content/uploads/images/medium/Look695EPS.jpg
http://www.pellossalo.fi/content/uploads/images/medium/20120513_003.jpg

Went through Nuovo, Super, C--then '95, '05 Ergo Record. Am completing a 2.5 yr experiment with SRAM (Force/Red), which will end as soon as I can get my first Shimano road group, Dura Ace 9000.

Shimano 7900. I've tried Campy, SRAM and even Di2. I like them all. Just that the 7900 fits my budget/personal preference for now.

If DA 9000 is what it's hyped up to be, it will be the grouppo on my next project. I'm also going to keep my eye out for cheap DA Di2 sets once the 11-speed one comes out.

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Flickr
2012 Cannondale CAAD10

A mix of Croce d'Aune and Nuovo Record

Voted SRAM

I ride SRAM shifters and derailleurs, Rotor crank and Ciamllo GSL brakes. I like to use third party cranks and wheels.

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You need some more pole options in order to get some interesting data:

Going to change from Shimano to Campy
Going to change from Sram to Campy
Going to change to Shimano to Sram
Going to change from Campy to Sram
Going to change from Sram to Shimano
Going to change from Campy to Shimano

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Wilier Cento Uno
Colnago Master X-light
Wilier 18carati

bike 1 : Dura Ace 7800
bike 2 : Ultegra 6500
bike 3 : Sachs 7 speed
bike 4 : Shimano XT 9 speed

Campagnolo Record 10 speed on all three road bikes.

Due to part restrictions/choices and crashes, none are complete groups though, and instead have parts from Chorus, Super Record and Centaur carbon (all now have Centaur 10 speed shifters) mixed in. All are fully ceramic'd.

SRAM 2012 complete group (quarq) on the Cervelo SLC
SRAM red/force group on the P4
Shimano DA7900 on the Canyon
Shimano 6700 on the CX

Have to say the DA7900 is my favourite. I do like the weight and ergonomics of the 2012 sram red but the shifting could be faster and smoother. DA7900 shifts like butter and from what I hear the 9000 will be even smoother. If they can get the weight down then thats the way to go!

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Canyon Ultimate SLX 2013 + DA9070 + Red Quarq + Corima Aero+ MCC (Ordered! 6.0kg)
Canyon AeroRoad + DA9000 + Lightning Power2Max + MCU's (6.5kg)
Cervelo P4 + G3 Powertap (7.78kg)
Cervelo SLC + SRAM Red 2013 + Red Quarq (6.8kg)

7800 shifters and r.mech, everything else is 3rd party, FSA chainset and f.mech.

Not very weight-weenie but it did cost me less than a 105 group a few years ago just after 7900 came out.

Shimano Ultegra 6700 on my SuperSix. FSA SL-K Chainset.

Tiagra 9sp on my Giant. Truvativ Chainset

Sram Red on bike one.
Sram Rival / Force combo on bike two.
Sram Apex on bike three.

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