Shimano Deore 9-Speed Mountain Bicycle Rear Derailleur - RD-M591

I'm on a budget and parts are getting scarce for the 9 speeds. I had a XTR before and loved it. Unfortunately, I sheared it and needed another which was not available. I bought this one and although the shifting isn't as crisp and it's not perfect (I ride a lot), it works. I'm a bit more careful with my shifts compared to before, but I'm not racing so it's been great. Great product, great seller and fast shipping.

I have two of these Shimano Deore 9-speed derailleurs that I use with newer Shimano Sora and older Shimano Tiagra 9-speed brifters on touring bicycles. I also use Sram 9-speed chains and Sram 11-34 9 speed cassettes. Those combinations work great with smooth and accurate shifts. Both of the derailleurs have so far been very reliable.

This was the first time I have changed out a Derailleur and I wanted it to be a definite upgrade. I went for the Prime and I was not disappointed. The installation was a piece of cake, the adjustment went precisely in step with the clear instructions, and my bike has been shifting flawlessly ever since.The cheapie OEM Derailleur that had worn out was a Shimano Altus, so the shifter did not present a problem and all I had to do was set the limit screws and the cable length. Since this was also a good opportunity to clean and lubricate the cable, I effectively, started over with a brand new system.The RD-M591 is a rugged, precision piece of equipment, unlike the sloppy, lightweight piece of garbage that it replaced. The amount of time I wasted trying to tweak the OEM Derailleur turned out to be a testimony to futility and absolute nonsense!My advice is this:If you are having trouble adjusting your Rear Derailleur, and you are following reasonable instructions, it's not you, it's your hardware. Spend a few bucks and replace it with the BLACK, all-metal RD-M591 (you don't need the gold-plated version) and then, you can lean back and just ride, ride, ride.

Bought this to replace a mid-90's LX rear running with a not-too-old Shimano 7-speed 12-28 rear, M361 48/38/28 front, and a no-name 5-6-7 speed chain. As others have said, although it's stated as a 9-speed, it works just fine w less, 7 in this case. The long cage is about an inch longer than the old LX, but no need to lengthen the chain in my app. The directions are good and should be followed no matter how much of an old hand you are. It shifts precisely and runs fairly quietly and smoothly. Not sure it is that much better than what I took off, or that it is really worth $50 (there are others cheaper), so 4 stars.

I got one of these to replace the Shimano Deore XT rear derailleur on my 2010 Giant Trance 26er. My old derailleur never worked well and was inconsistent in shifting up to larger sprockets. The new Deore unit shifts perfectly. It's a little heavier, but I don't care because I ride for recreation and excercise, not racing.

I have no idea what “Sheerness” means so no rating in that category, but this is a nice mid-priced derailleur that works well with my 9 speed cassette. I trashed my XTR derailleur but didn’t want to spend the money on such a high-end replacement since I had a new bike on order. This was just to get me through until the new bike arrived and it did a good job at that, and I expect it will last a good long time on my back-up bike.

I'm using this on a bike I built on a Mongoose Salvo frame. The wheels I'm using take a freewheel so, it has a 7 speed 12-28 freewheel on it. Setting the limiting screws was easy and, there was plenty of adjustment. It's paired with a 22-32-42 front crankset, a Shimano Altus front derailleur, and Microshift shifters. Shifting is smooth and fast. I would recommend this derailleur.

I bought this derailleur to use with some Shimano 5700 10 speed shifters so I could use a larger cassette 11-34 and the 9 speed mountain bike derailleur works great with Shimano 10 speed road shifters