>>1110455>But if you're talking about technical riding in a downward direction of any type, not a fucking hope, the chain retention benefit of 1x beats the shit out of any disadvantage it has in efficiency.When riding down you are most likely at the higher end of the gearing range, which is - smallest cogs on the cassette. Due to how rear mechs work - there is least amount of chain tension on those gears. Essentially you are down to how well N/W ring and the clutch can hold the chain.
That works up to a random point when wear overwhelms the ring chain retention capabilities. To safeguard against this you need a guide ( coincidentally, most people ride them ).
Moreover - due to lowest chain tension and long mech cage you get most chain slap on the 1x system.
Properely set up 2x with the same range will be deathly silent and have the same chain retention capability.
Don't let me start on the gear selection.
I owned both. My current mountain bike is a 1x only and it is the only thing I despise about it. Pic related - my mundy.