ATB

Big tires and short chainstays create two issues. First, how do you fit the chainstay in the tiny gap between the tire and chainring? Second, if the chainstays are really short, how do you create enough tire clearance behind the seat tube? A curved tube is the obvious answer, but bending a 35mm Ti tube limits our flexibility to customize the tube’s wall thickness and makes it harder to create a precise seat tube angle. Our 3D Clearance System solves those issues.

The 1x specific yoke threads the gap between 29×2.6” tires and up to a 40t chainring with a 52mm chainline, all with super short 430mm chainstays. (The design also gives us flexibility to accommodate up to 42t chainrings with a 47.5mm gravel chainline, which just reduces tire clearance to 29×2.2″. Choose our Gravel model for bigger chainrings.).

The 3D printed seat tube knuckle then shifts the seat tube forward, creating space for the tire behind the seat tube while giving the frame a perfectly consistent seat tube bend for a precise frame geometry and saddle position every time. The short design of the knuckle also allows for a longer straight segment above the bend than with a simple curved tube, leaving plenty of space for long travel dropper seatposts.

Flat bars give you more control on rough trails, while drop bars give you more hand positions for long-ride comfort. As our vision for the dream ATB formed, we realized that building the bike to work with both handlebar styles would make it exponentially more versatile.

With the right component and design choices, including careful selection of handlebar shapes and widths, wireless shifting, and couplers in the brake lines, you can switch from mountain to drop bars in less than 10 minutes and without any brake, shifting, or fit adjustments. Any given ride, simply choose the bars that match the day, and you’re on your way.

Most mountain bikes have suspension forks or suspension-corrected rigid forks. Suspension forks are long, typically at least 10cm longer than gravel forks. The big downside of such long forks is that they can force the bars to be too high and limit our flexibility to customize the bike’s fit. That’s not usually a problem for a pure mountain bike, but for a bike like our ATB that is purpose built for longer rides on more varied terrain, a precise fit is just as important as it is on road and gravel bikes.

That’s why one key to the ATB’s versatility is using a relatively short fork without limiting tire clearance, allowing us to get the handlebar height correct for every fit and giving you the traction and comfort of wide tires. Our ATB will come standard with Whisky No.9 MCX+ fork, a great carbon option with a 430mm axle-crown height and space for 29×2.6” tires, cargo mounts, and internal dynamo wire routing. Or, for the best possible ride quality and handling, upgrade to our brand new ATB fork, with clearance for 29×2.6” or 27.5×3” tires, and available with custom offsets, cargo mount options, and finishes to perfectly match your Firefly frame. (Other forks available on request as well.)