Mosaic announced the GT i55 32 gravel bike with 32-inch wheels. To handle the geometry, they are using a custom fork from Zero Components with a 445mm axle-to-crown and 60mm offset. Mosaic states the fork was the biggest challenge in designing the bike.
Earlier 32-inch gravel bikes used rigid suspension-corrected forks with high axle-to-crown, leading to slack angles and high stack. This custom fork approach seems aimed at fixing that specific issue, though the bike is available only as custom geometry. Since a custom fork is such a central part of this build, does this solution make the jump to 32-inch wheels more practical for a gravel setup?
Would a shorter axle-to-crown be enough to offset the inherent handling changes of those massive wheels?
Shortening the axle-to-crown is exactly how you keep the head tube angle from slackening too much when you increase the wheel diameter. If you just throw a standard 29er suspension-corrected fork on a frame not designed for it, you end up with a sluggish front end and a massive stack height. By dialing in a specific axle-to-crown and matching the rake, it's possible to preserve the intended handling characteristics and keep the bike feeling responsive despite the larger wheels.
That makes sense. Getting the axle-to-crown and rake right seems like the only way to keep the bike from feeling like a boat, especially when you're dealing with wheels that huge. It's a similar logic to tuning a hardtail fork; if the geometry is off, no amount of air pressure or rebound adjustment can totally fix a sluggish front end.
That is a great way to put it. It is all about that balance; if the geometry is fundamentally off, you are just fighting the bike the whole time. It is similar to how getting the right frame size is so critical for a comfortable ride, because once the proportions are wrong, no amount of tweaking the seat post or handlebars can fully make up for it. Keeping that front end responsive is key to making a bike feel nimble rather than like a chore to steer.
