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So far it’s a solo ride.

BOTW: Brennan's Back-to-Business Mosaic GT-1 AR

Peter Harrington |

This edition of Bike of the Week isn't just about a new set of wheels we're rolling out of the door to a happy client. It's also the day AC's gravel pro Brennan Wertz unveils his new rig for his hotly anticipated assault on the 2023 off-road race season. And this year, changes are afoot. After riding for Pinarello in 2022, Brennan is returning to the bike that helped launch his racing career in 2021, a freshly updated GT-1 from none other than Colorado's Mosaic Cycles

"For years, I've dreamt of designing and building my own titanium 'do-everything, go-everywhere' all-road bike," Brennan tells us. "I've spent countless hours considering ideal geometries, contemplating perfect wheel/tire combinations, and obsessing over gear ratios for this hypothetical dream all-road bike. It would be capable and compliant, with clearance for at least a 35c tire, while maintaining the snap and liveliness of a pure road bike." 

Brennan's race-proven spec is a lot to ask of any bike. But the Mill Valley local, who AC backed in his debut gravel year atop an earlier iteration of the Mosaic GT-1, is happy to report that Mosaic's new GT-1 AR (short for all-road) - the first Mosaic with internal cable routing no less - checks all those boxes and more. "The new model of GT-1 from Mosaic is truly something to behold," Brennan enthuses. "And it seems only fitting that I should celebrate signing with Mosaic Cycles for the 2023 season by helping them launch the bike of my dreams,  built to my exact specifications. I cannot wait to begin stacking up some mega all-terrain mileage upon this trusty steed!"

Above Category's relationship with Mosaic goes back a long way. Twelve years, to be exact. As our co-founder Chad Nordwall recalls, they've been a great partner to work with, keen to collaborate whenever a fun project comes up. "A couple of years back, we needed a bike in a pinch after finding out Brennan had got an Unbound race entry," he says. "Mosaic stepped up, and after seeing the success of that, it was natural to start working on more projects with them, like the bikepacking trip that Derek and Brennan did with Mosaic's Aaron and Mark. These sorts of things make working with builders like Mosaic so rewarding. Also, they make fantastic bikes!"

And like all of us here at Above Category, Chad is equally enthused about seeing Brennan rock the off-road scene on a metal machine, which will include the GT-1 AR, and Mosaic's MT-1 for the mountain bike races on his calendar. "This is going to be a really fun year," Chad notes. "I'm super excited to have Brennan back on Mosaic for 2023. It just helps show these bikes aren't just works of art to be hung on a wall somewhere, but equally, hardcore bicycles for racing at the highest levels."  

Without further ado, let's turn to the build details of Brennan's GT-1 AR. "This particular Mosaic is one of the first the brand has built with a fully integrated and internally routed frame set," Chad notes. "It looks super clean. It looks pro. And with the 54/40 chainring combination, you know the person riding it is putting out some serious watts."

And then there's the paint and complementary components. In Chad's opinion, it pops. "Everything looks balanced, in the right place - neat. And the Lightweight Pfadfinder Evo Schwarz Edition wheels and Rene Herse tires finish the look perfectly." 

The Build

Frameset: Mosaic GT-1 AR Integrated
Handlebar/Stem: Enve Aero Bar (42cm) & Integrated Aero Stem (120mm)
Seatpost: Enve 27.2mm seatpost
Group: Shimano Dura Ace 9270 Di2 Disc w/ 11-34 cassette
Drivetrain Upgrades: CeramicSpeed Coated OSPW, Coated BB, Coated Headset, and upgraded pedal and hub bearings
Crank: SRM Origin PM9 with Shimano 9200 54/40t Chainrings
Road/Allroad Wheels: Lightweight Pfadfinder Evo Schwarz Edition
Gravel Race Wheels: Enve SES 4.5
Tires: Rene Herse Bon Jon Pass 700 x 35c Endurance Casing
Cages: Arundel Mandible Cages, Team Edition
Pedals: Shimano Dura Ace pedals with Ceramicspeed opgrade
Saddle: FormCycling Throne RS Carbon


Brennan's Mosaic GT-1 AR

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