Thank you CRASH. Actually did a comparo of the different 1X Sting Rays. They're all SRAM drivetrains. The orange Fastback has a Campy headset and front hub. Here's the SRAM X0 9 spd mech on the orange bike. On this yellow one I used the next model down with a short cage. X9 9 Speed 10 Speed Scrambler has the X9 10-speed which also includes a clutch on the cage which prevents chain drops. They all shift great. The orange bike was a challenge using the stock Mag sprocket. Yellow bike is the smoothest mainly because it is using an narrow/wide front chain ring. Thanks chewy!!