GT-1 45 & GT-2 45 Chainline Update



GT-1 45 & GT-2 45 : Gravel Chainline


Our most popular framesets, the GT-1 45 and GT-2 45 are getting a little update. Starting today, by default, all GT-1 45 and GT-2 45's will be built specifically for use with a gravel groupset/chainline. These groupsets include Shimano GRX, SRAM Force Wide, and all SRAM XPLR variations. So, what is a gravel chainline, you say? Learn more below...

When designing a gravel bike for riding fast over rough terrain, one of the biggest decisions to be made is tire clearance vs. chainring clearance & groupset compatibility. Big tires rock, and they continue to get smoother, faster, and more fun to ride. As tires get wider and the demand for clearance becomes even more important, the "window" that we have to slot the chainstay through between the tire and the chainring becomes narrower and narrower. Our solution to this has been to manually squish the chainstay and add a small dimple to the outside to give the chainring more room to breathe.


Moving forward, we will no longer be squishing/dimpling the chainstay by default. By requiring the use of a crankset with a gravel chainline, we gain up to 3mm of additional chainring clearance which negates the need for the dimple. This also comes with several benefits for you, the rider.


1: Increased Tire/Mud/Debris Clearance - By moving the GT-1 45 an GT-2 45 to a gravel chainline, we're able to squeak a few more millimeters of tire clearance out of the rear triangle. Whether that means you want to run a slightly larger tire, or just have more room for those extra muddy & sloppy days, you're in luck.


2: Increased Chainring Clearance - The GT-1 45 will now comfortably fit a 1x 46t chainring, so, mount up those big tires and big gears and let's go smash some gravel.


3: Improved chainline - I mean... who doesn't love a more efficient and quieter drivetrain?! By utilizing a crankset with a gravel chainline, especially if you're running a wide range 1x setup, you will benefit from a more efficient and quiet drivetrain system. In most gears, the chain is able to maintain a straighter line between the chainring and the cassette meaning less unnecessary friction and noise.

Upon request, we can still squish & dimple the chainstay for use with non-gravel chainline cranksets. If you're planning to build your GT-1 45 or GT-2 45 with a 2x crankset, or any other crankset such as Campagnolo EKAR, Cane Creek EEWings, White Industries, please work with your Mosaic dealer to make sure that is specified during the build process.


We'll see you on the dirt!


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