Ground-up redesign delivers Mosaic’s most capable gravel platform yet with 55mm tire clearance, in-house designed fork, and modern integration.
Gravel riding has changed. Courses have become rougher (and muddier), riders are venturing farther from pavement, and wider tires have become an essential tool for riders seeking more speed, comfort, and confidence over unpredictable terrain. The new Mosaic GT-1 i55 and GT-2 i55 were built for exactly this evolution.
Representing a complete redesign of the company’s gravel platform, the GT-1 i55 and GT-2 i55 become the most capable gravel bikes Mosaic has ever produced. Engineered around clearance for up to 55mm (700c x 2.2”) tires, the new platform combines a completely reimagined rear triangle with a 3D-printed yoke, a new Mosaic-designed gravel fork, updated frame standards, and geometry refined through years of experience building race-proven titanium gravel bikes.
“The goal was never simply to build a bike that fits bigger tires,” says Aaron Barcheck, Founder and Lead Designer at Mosaic Cycles. “Every change had to earn its place. The rear end, the fork, the frame standards, everything was designed together so the bike would feel every bit as lively and responsive as our previous gravel bike while giving riders the capabilities they’ve been asking for.”
Mosaic GT i55 Gravel Platform Key Updates
- 55mm Tire Clearance: Mosaic’s most capable gravel platform to date.
- New Mosaic-Designed Gravel Fork: Designed in-house with 55mm tire clearance, fully internal routing, suspension-corrected geometry, and fender mount-ready.
- Ground-Up Rear Triangle Redesign: New frame architecture increases capability while preserving responsive handling and ride feel.
- First 3D-Printed Titanium Component: An exclusive titanium rear yoke meets the tire-clearance demands of modern gravel bikes while maintaining stiffness and drivetrain clearance.
- Modern Integration: Updated routing, UDH compatibility, T47 bottom bracket, and clean cockpit integration across both models.
- Batch Built or Made to Order: Available for fast delivery through the Batch Built program (ships in 3-5 business days), or offered as a Made to Order bike where riders can fully personalize the build with custom geometry and finish work.
Designed around the Modern Gravel Rider
Since the introduction of Mosaic’s original GT platform, gravel riding has continued to evolve. Races have become rougher, adventure rides have become longer, and riders increasingly expect a single bike to handle everything from fast dirt roads to muddy backcountry terrain. The GT-1 i55 and GT-2 i55 were designed around these changing demands.
Accommodating a 55mm tire required far more than simply making room for a bigger tire. Mosaic completely redesigned the rear triangle, shortening chainstay length from 435mm to 430mm while simultaneously creating clearance for significantly larger tires.
At the same time, Mosaic developed a new in-house designed gravel fork after finding that existing options no longer met the performance, integration, and geometry requirements of its next-gen gravel platform. The result preserves the responsive handling Mosaic riders expect while dramatically expanding the bike’s capability across a broader range of terrain.
Engineering that Solves Real Problems
At the center of the redesign is Mosaic’s first-ever 3D-printed titanium component with a exclusive rear yoke. The new design provides clearance for up to a 55mm tire while accommodating modern 1x gravel drivetrains with chainrings from 38 to 50 teeth.
Working together with a newly offset seat tube, the system allows Mosaic to fit substantially larger tires without increasing chainstay length or compromising ride quality.
A Fork Built for Where Gravel is Going
Increasing tire clearance wasn’t simply about redesigning the frame. It also needed a fork capable of supporting the way modern gravel bikes are ridden, and the conditions we sometimes find ourselves in… ahem Unbound ‘26, ‘23, ’15, ‘08….
Unable to find an existing fork that met every requirement for the new platform, Mosaic designed its own fork, developed specifically around the GT i55. The new fork provides generous clearance for 55mm tires with room to spare for muddy conditions, while incorporating fully internal brake routing and suspension corrected geometry with a 415mm axle-to-crown length.
That geometry also makes the GT i55 compatible with modern gravel suspension forks, giving riders the flexibility to tailor their bike for everything from high-speed racing to rugged backcountry adventures.
Modern Standards Throughout
Alongside the redesigned frame, the GT-1 i55 and GT-2 i55 incorporate the latest generation of frame standards introduced across Mosaic’s 2026 lineup.
- The GT-1 i55 features an oversized IS52 head tube, fully internal cable routing, a T47 bottom bracket, UDH compatibility, and is delivered as a frameset with an ENVE In-Route stem and seat post.
- The GT-2 i55 utilizes semi-integrated routing through a Cane Creek HCR cockpit while maintaining the clean aesthetic and serviceability that define Mosaic’s Level-2 platform.
Availability & Ordering
While engineering has evolved, the philosophy behind every Mosaic bike remains unchanged. Each GT i55 is still hand-built in Boulder, Colorado, and can be tailored to its rider through Mosaic’s Made to Order program with custom geometry, personalized builds, and any current finish work, including Mosaic’s Artist Series colorways.
Visit mosaiccycles.com for availability, lead time, and to find a partner near you.
- GT-1 i55 framesets starts at $8,250
- GT-2 i55 framesets starts at $5,000
For riders looking for faster delivery, both models will be added to Mosaic’s Batch Built program later this fall, which offers eight standard sizes and several paint options. Once available, in-stock bikes ship within 3-5 business days, with backordered models shipping in approximately 4-6 weeks.
Color options and pricing will include:
- GT-1 i55 Batch Built framesets:
- Pearl Dark Graphite Matte
- Starting at $7,500
- GT-2 i55 Batch Built framesets:
- Ghost Finish
- Starting at $4,250
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About Mosaic Cycles
Mosaic Cycles builds handmade titanium bicycles in Boulder, CO. Excellence in precision fabrication and efficient business practices balance Mosaic as an industry leader, creating meaningful cycling moments and enduring products. Mosaic partners with select bicycle shops around the world to help share the experience of riding a titanium bicycle.