Cheers!
In general terms, over the last five or so years, all the medium frames I’ve ridden have felt small where in most cases the larges have not felt too big.
Part of this is that steep seat angles really shrink effective top tube lengths (even some larges feel small sitting - Kona Satori was a prime example) and part of this is that local terrain is steep and technical and the body position between the wheels with a 40mm stem is better than with a 60mm stem. Certainly, to get most mediums to fit comfortably climbing I’m on a 60mm.
I find the 16° sweep SQLab bar my hands back a bit and can split the difference a bit, but it's more than just a change in the relative Reach so it makes less of a difference in stem length choice than most folks would assume. I'm happily running a 40mm stem + SQLab bar on the Lux but wound run a 30-35mm stem with a more traditional 7-9° bar on the Large. That's pretty standard for me on a modern large, though certainly if the average medium frame gets much bigger than for bikes without crazy steep effective STAs I could see myself on a medium with a 50mm stem.
Specific to the Lux, a big reason I went large is that the fit is very similar to my own custom Waltworks hardtail. My hardtail has significantly longer chainstays and a significantly slacker HTA, and doesn’t have the ridiculous seat mast, but when I sit on both bikes they’re instantly comfortable. I actually run a 1cm longer stem on the Lux with the same bar, which accounts for how much more the Reach grows on a hardtail through the travel.
The similarities to my own custom frame aside, the other reason I went large with the Lux is the wheelbase. With the relatively medium stays and the relatively steep head tube angle I knew there would be an extra degree of stability.
Personally, I think the only downside of the large is the seat mast. The bike would be more fun with a 150mm or even 170mm dropper.
Sept. 17, 2021, 9:05 p.m. - Andrew Major
Cheers! In general terms, over the last five or so years, all the medium frames I’ve ridden have felt small where in most cases the larges have not felt too big. Part of this is that steep seat angles really shrink effective top tube lengths (even some larges feel small sitting - Kona Satori was a prime example) and part of this is that local terrain is steep and technical and the body position between the wheels with a 40mm stem is better than with a 60mm stem. Certainly, to get most mediums to fit comfortably climbing I’m on a 60mm. I find the 16° sweep SQLab bar my hands back a bit and can split the difference a bit, but it's more than just a change in the relative Reach so it makes less of a difference in stem length choice than most folks would assume. I'm happily running a 40mm stem + SQLab bar on the Lux but wound run a 30-35mm stem with a more traditional 7-9° bar on the Large. That's pretty standard for me on a modern large, though certainly if the average medium frame gets much bigger than for bikes without crazy steep effective STAs I could see myself on a medium with a 50mm stem. Specific to the Lux, a big reason I went large is that the fit is very similar to my own custom Waltworks hardtail. My hardtail has significantly longer chainstays and a significantly slacker HTA, and doesn’t have the ridiculous seat mast, but when I sit on both bikes they’re instantly comfortable. I actually run a 1cm longer stem on the Lux with the same bar, which accounts for how much more the Reach grows on a hardtail through the travel. The similarities to my own custom frame aside, the other reason I went large with the Lux is the wheelbase. With the relatively medium stays and the relatively steep head tube angle I knew there would be an extra degree of stability. Personally, I think the only downside of the large is the seat mast. The bike would be more fun with a 150mm or even 170mm dropper.