This year brought together 23 custom frame builders and brands to the Enve headquarters in Ogden, Utah to showcase the best that each builder could put together. The majority of the creations were road or gravel bikes, but there were also two mountain bikes that stood out.
Let us introduce you to Viral Bikes‘ first full-suspension bike. The Viral Optimist 160 featured 3D-printed titanium lugs with custom tubes to create a custom-geometry mountain bike. This isn’t Domahidy’s first time building a bike brand: he helped build Niner Bikes and its unique CVA Suspension as well. A lifetime of work on CVA guided him to what he feels is “the cutting edge of mountain bikes.”
Of note in this image: the bolted-on seatstay bridge is how Viral can install and remove a Gates belt drive without needing a breakaway point in the seat stay or chain stay.
The Optimist 160 has a whole lot going on, but there are two core tenants here: use of the new Pinion SmartShift electronic shifting gearbox, and custom geometry to suit a rider’s fit and riding style.
Viral Bikes founder Steve Domahidy touts three main benefits of designing the Optimist 160 around a Pinion gearbox. No derailleur removes two pounds of unsprung weight at the back of the bike. The back end of the bike is “wildly more active” as a result and far more tuneable as well. Additionally, anti-rise numbers are the same regardless of which gear you’re in. And as a bonus, there’s no pedal kickback from the Pinion gearbox either.
The Optimist 160 will come exclusively with the SmartShift gearbox. Rejoice, Gripshift haters!
3D-printed titanium generally has a set of lattices inside that add strength to the structure. Viral uses Electron Beam Melting (EBM) that prints parts at 700 degrees Celsius, the annealing temperature of titanium. As such, the titanium printed parts are already heat treated as they’re produced.
The Optimist 160 uses a single-pivot rear suspension with a flex stay out back.
Between the belt and controlling the final drive ratio, Domahidy says there’s no need to further deaden the bike or add complication to the frame. Titanium’s inherent flexiness and resistance to fatigue should aid in that performance as well.
Anti-squat at sag is about 115 percent, according to Domahidy. The suspension is said to be tuned with small bump compliance in mind, with about a 15% progression in leverage ratio, starting out at a little over 3:1 and ending at 2.44:1.
The details are killer. The inner custom bike geek within me loves how the rear brake caliper is elegantly integrated into the rear triangle.
3D printed 6/4 titanium lugs, carbon tubes, and a whole lot of love. As currently constituted with the SmartShift gearbox, Rockshox Zeb fork and Super Deluxe shock, and Enve M7 wheels, the Optimist 160 weighs in at about 35 pounds (15.9 kgs).
Expected availability of the Viral Optimist 160 is early 2024, with a turnaround time of about two weeks. More information: www.viral.bike
Chumba Bikes is a small company based out of Austin, Texas, spearheaded by Vincent Colvin. Steel and titanium are usually their mediums of choice for building a frame, all with an eye toward functionality and intention in their design. Chumba brought along a custom-painted Sendero hardtail paired with a color-matched ENVE rigid carbon fork. Chumba touts its frame’s capability in the lightweight trail segment, but many end up using theirs for bikepacking.
Just about every Chumba features sliding dropouts for use with either geared or singlespeed drivetrains. Singlespeed ain’t dead, folks.
This Sendero received a custom finish that extends to its stem, bars, and even integrated fender.
The Enve Mountain Fork features a flip chip at the dropout to modify the bike’s handling. We love just how the bolts are precisely painted in a half green, half blue.
Photos: Troy Templin
Want to ogle even more custom bikes? The road bike gallery is over on Velo at this link, and the gravel bikes can be found here.