Omni Prime: an Ultralight Build at 15.98lbs
Sep 13, 2017
article & images by Nick Salazar
Over time, we have done quite a few bike builds. A subset of those are what we call our "Service Course" builds, extra-special projects done with particular care taken to make the bike as snazzy as possible. Today, I'm happy to show off a bike I'm calling "Omni Prime," basically the lightest sprint-ready build I could come up with for our flagship Omni bike. This build comes in at a feathery 15.98lbs as pictured. That's a pretty darn light weight to achieve. We figured 16lbs would be a tough but exciting goal. And while Omni isn't exceptionally heavy, it isn't considered an ultralight frame by any means, so we had to take some special care to shaving grams down to hit the target weight. We began, of course, with the Omni Complete Frameset, including Alpha X aerobars, Omega X brakes, etc. Then we got to work.
First, we start with the obvious choices. Dash Cycles takes care of the wheels, a 60/Gretchen Disc tubular combo that is amazingly light but as aero as they come. For tires,we used the beautifully-smooth-rolling Vittoria Corsa Speed Tubular 23mm up front. In back, it's nearly the same model - a Vittoria Corsa Tubular 25mm rear. The Corsa in back (as opposed to the Corsa Speed up front) has slightly higher rolling resistance, in exchange for a wider tire (more air volume, more comfortable ride), and presumably an aero benefit from filling in the rear wheel cutout more). This is one of the fastest tubulars ever made, and it rides like a dream.
Dash also provided the Tri.7 saddle and seatpost combo. Even if we didn't have the integrated seatpost combo, the Tri.7 (and its successors the Stage.9 and TT.9) has been my saddle of choice since it was launched, and I still absolutely love it. To anyone who has saddle discomfort issues, I tend to point straight to Dash as my immediate recommendation. That's why it comes stock on all our complete Omni builds.
Crankset: Lightning Cycles crank in 165mm, with a custom Fibre-Lyte chainring in 50t, with TriRig logos etched above each chainring bolt.
Drivetrain: custom SRAM eTap 1x setup. To save weight, we skipped the Blips and just attached the BlipBox right onto the right-hand Gamma extension. The end result ended up being lighter even than a mechanical RED 1x setup once shifter cables/housing were included. Then we put on a CeramicSpeed OSPW cage, UFO Chain, and PressFit bottom bracket, to minimize drivetrain friction. The now-discontinued blade levers from 3T are the lightest I've ever seen, at 60g for the pair. They aren't my favorite in terms of function, and I much prefer the Shimano BL-TT79 levers that we normally stock with Omni. But for an ultralight sprint-tri bike, they offer more than enough stopping power. Just a mushy feel, and a pretty weak return spring.
Additional customizations: One big project for the bike was the creation of one-off arm cups. We aimed to make the same basic shape as our well-loved Ergo Cups, but we were able to save a LOT of weight by eliminating all adjustability from the cups. These offer only one position, and not a ton of padding. These work great for short efforts, but would not be fantastic for Iron-distance racing. I'd probably swap back to the Ergo Cups for distance events. Next up, we machined some custom alloy skewers with custom titanium bolts (the stock versions of our aero-matched Omni skewers are steel). We haven't done long-term testing to know whether these are safe as a regular consumer item, but as a custom one-off race item they do the trick. The Omni's storage box (behind the stem) has had its bottom cut off, and it was glued in place, saving the weight of the bottom half of the rubber, and the attachment hardware. Harder to clean, but lighter on the scale. The Front Derailleur Replacement Cap (the part that completes the aero shape of the bike when the FD hanger is removed) was glued in place rather than bolted ... again in the name of saving a couple grams. And to finally get over the finish line and under 16lbs, standard housing was swapped for Alligator i-Links.
This was such a fun project to put together. In terms of a day-in, day-out build, I certainly prefer the creature comforts of the Ergo Cups, the Shimano brake levers, and of course putting some hydration on the bike. All of that might add maybe 200-300 grams to the bike, and still keep it in the 16lb range. But for a sprint, this is an absolute killer machine, and it's just fun to build up a sub-16 bike once in a while.
Thanks for reading! To learn more about the Omni, check it out in the TriRig Store.