What went wrong with this upper pulley on Sram derailleur? #bikeservice

[thefucrew]

Directional chain ???
Wow !!!
I would never had known about this.

[silentumexcubitor]

On upper pulley, the "L" was for LEFT, not lower....

[ignaciosevil]

that still exist? that was sold in 2016..

[stuart]

I hate some of the names, berms, it’s a friggin bend

[jayfinch]

The direction of the chain is unclear. The opposite direction is correct or incorrect? Thx.