We threw up a flash poll for Slowtwitchers a few weeks ago, asking, “What's your preference? Parting up a new tri bike the way you want from a reasonably-priced bare frame, or buying a complete bike several hundred dollars cheaper than that bike would cost parted up?”
The results were almost 50/50, and this is a big change from a half-dozen years ago, when almost no one wanted to part-up a new bike.
Obviously saddles, tires, pedals, wheels top the list of products that riders are particular about. Some prefer Shimano electronic, SRAM's eTap is a very compelling new option and this has the advantage of being easier for end-users to install, as it is largely wireless.
The two new compelling handlebar options are TriRig Alpha series bars and 3T's new Revo (though possibly with a different extension).
Brakes? External (not integrated) would be the solution for popular frame+build platforms like Felt's IA10, Cervelo's P2/3, QR's PR5 and one of my favorites for this, Orbea's OMP. This often means Magura's hydraulic centerpulls found on Cervelo's P5, but these need a little aftermarket work: you take the brake blocks out and shave down the pads a bit, maybe on the flats of your bench grinder wheel, to make room for wheels with a brake surface width greater than 25mm. The other option is right back to TriRig.
These TriRig rigs are popular, and the build-from-scratch bikes are popular. Here's a galleries of Trigged bikes.
Crowie's Shiv was built, with PRO bars and TriRig brakes.
Mr. Alexander has decamped for a new sponsor. in Crowie's case it's Argon 18. It is unlikely he can use TriRig on an E119, which is soup-to-nuts Argon 18 in brakes, stem and bars.
Ben Hoffman's bike is another TriRigged Shiv.
Ben's is one pimped bike.
Above and below is Team Cofidis on 3T bars and TriRig brakes.
Cofidis rode Look bikes in this photo but now is on Orbea. I don't see any reason why one wouldn't also ride these brakes on Orbea's TT bikes.
Above is great TT and hour record rider Jack Bobridge, rockin' TriRigs on a P5 more typically seen sporting Magura hydraulic center-pulls.
Nick Salazar riding his own stuff. (I know exactly what that feels like, Nick.)
Above are TriRig brakes on a handcycle.
Pat Evoe is fully TriRigged: brakes and bars. If you look at the pads bove the pursuit bar centerline, you see why these bars are the choice for riders looking for lowness beyond, perhaps, what the bike frame grants.
Above is a TriRigged (bars and brakes) Cervelo P4. The P4 never was fully appreciated, and this customer treated his P4 well. Note that this customer was also budget-minded: Renn rear, FLO front.
The Orbea OMP above may be the best looking frame on which to hang TriRig components.
Here's a customer's Dimond with TriRig's parts.
If you've got a couple of bucks to burn, TriRig on a Dimond is a good way to burn it. But where are the carbon wheels?!
Tim Don, ENVE and TriRig conspire to make a Shiv look especially good.