Shimano Deore RD-M4120 Rear Derailleur - 10-11 Speed

I have been modifying a steel bike for light touring. Initially I installed this derailleur with an 11-36 10-speed cassette and a triple crank, but I wanted to simplify the drive train with a 46-30 and an 11-42. Although this combination exceeds the published chain capacity for the derailleur, it works quite well, with good chain tension, and able to reach all gear combinations, although I would never use it in 46/42. The derailleur cage rubbed slightly on the chain below the lower jockey wheel, but I bent it outward about one millimeter for clearance. It now shifts and runs quietly.

Did exactly what I wanted it to. Installed without any headaches, adjustments were straightforward. I upgraded from a 3x8 to 1x10 on a mountain bike. Well built for the cost. Deore is good.

Product was in perfect working order right out of the box. Rails the chain onto the gears in a smooth motion.

I bought this to build my budget gravel bike. Great cost and shifts just fine if your expectations aren't too high. Be sure to install it right and it'll work fine for you.

Bullet-proof. Value. Heavy like a rock. Huge. Meant for MTB systems. Can't say it'll work on a road bike with road shifters. But it won't make much sense using it that way.

Desviador trasero estupendo. Todo en su caja original y funciona perfecto y compatible con cassette y desviador de 10v 11-42. Muy conforme. No puedo decir nada de la durabilidad porque lo instalé recién hace un mes, pero aparenta un material shimano bueno como debe ser.

Works great, used it on my Roscoe 6

Shifts my 11x42 10 speed cassette very well