2021 Trek Fx sport 4 geometry and sizing
 

I bought a 2021 Trek Fx sport 4 carbon (new) in 2023 , to add to my n+1 which is a 2020 fx 3 and I always been confused about this generation fx sport carbon bike geometries. The Large Fx 3 bike, has a similar reach and stack to that of Medium 2021 Fx sport 4 carbon, why is the FX sport carbon (2021) one size larger almost for a given size ?

Is 2021 Fx Sport Carbon size Medium = Trek Fx 3 Large, interns of sizing ? I'm 6' feet tall and 32.5inseam

2021 Fx Sport 4 Carbon
https://www.trekbikes.com/us/en_US/b...ort-4/p/32262/

2020 Trek Fx 3

https://www.trekbikes.com/us/en_US/b...-disc/p/35021/

Because they're different bike types and are designed to fit differently.

The FX is for beginners who like to be upright so short top tubes and taller head tubes.

https://cimg6.ibsrv.net/gimg/bikefor...3e6e277ad2.jpg

thing is large fx 3 has 58.6 stack and 39.8 reach, large fx sport 4 has 61.1 stack and 41.1 reach so stack and reach is bigger essentially a bigger bike , no?

I'd say it's more a "different bike"