true....but it doesn't get you out of the requirement to match cable pull of shifter and mech.
At the risk of repeating myself, I'll.....errr.....repeat myself.....
Now, I have never come across a front mech. which specifies seat tube angle, but when MTBs had 26" wheels and high bottom brackets, and Trekking bikes had 700c wheels and low BBs, Shimano used to make (eg Deore) front mechs. for 2 different "ranges" of chainstay angle, which is the included angle between the seat tube and the chainstay, which is governed by wheel size and BB height.531colin wrote: ↑13 May 2021, 1:33pm
I think the really important things are
the position of the mech....ie close to the teeth, not halfway up the seat tube, and parallel to the chain in middle ring/middle sprocket.
the right number of teeth difference between middle and big ring
the right chainline
matching mech and shifters; both MTB in this case so OK I think..........
So one way of getting a front mech. where the "tail" of the mech. fouls the chainstay before its close enough to the chainring teeth could be to use a mech. designed for a large chainstay angle on a bike with a smaller chainstay angle; but using a small chainring with a mech. designed for a big chainring will give the same problem.