Altus Mountain Bike Rear Derailleur - Direct Mount - RDM310

A great derailleur for the price, shifts perfectly and quietly and is totally silent while operating on all sprockets. It is easy to install with a just a few allen wrenches, I didn't bother taking apart the chain, I just disassembled the cage slightly to get the chain inside it. Adjusting was slightly more difficult. The only issue is that there are no paper instructions for installation and especially ADJUSTING it. It is essential to adjust the low and the high limits to align the upper jockey wheels and chain with the low and high sprockets, THEN just as importantly, when derailleur is on smallest sprocket remove ALL slack on the cable by pulling the cable tight when the cable attachment bolt is loose, then retightening the bolt, and/or by screwing the cable adjustment barrel until the derailleur just starts to move inward to the next gear. Maximum rear sprocket size is supposedly 34 tooth, and I found it best the adjust the B tension screw inward quite a bit (the one on the bracket that limits the derailleur front and back swivelling) to help the upper jockey wheel clear the larger sprocket (28 tooth in my case) better. Once installed and adjusted, it worked PERFECTLY every time.

I bought this derailleur to replace the stock unit on a beach cruiser that I converted into a motorbike. I needed something sturdy and, most importantly, with enough clearance to fit around the HUGE sprocket that I have on the bike (34 teeth). This unit fit the bill perfectly - only required some minor adjustment with the set screws and within 15 minutes I was back in action. The only thing I needed to do we steal a longer B-screw (the screw that determines how far the derailleur's upper flywheel sits from the cassette) from the old derailleur, because the screw that came with this one wasn't long enough. This is ONLY because my bike is a beast of customization and I needed to improvise - but the longer B-screw worked flawlessly. In case anyone else out there is attempting to build a shiftable motorbike, I highly recommend this rear derailleur. It's super easy to install, came properly tuned right out of the box, is very sturdy and solid when riding, and most importantly it fits over just about any sprocket size you might have in the back! They make a ridiculous 42-tooth sprocket which I'm going to try putting on this bike (because the clutch doesn't like taking off even with the 34T sprocket...) and I'm confident this derailleur will even work with that.

Having a problem adjusting the gears but that's my problem not Shimano's. Fit easily, looks great, and a new Shimano quality derailleur for < $17 is a very compelling to change your old one out like I did.

Had to replace mine. Easy to install. Easy to adjust speeds. Works as it should.

This derailleur is pretty decent and is a cost effective and performance worthy piece of machinery. I chose this over Acera for price and performance. It is a little heavier. However, I feel that the performance is smoother and more accurate than Acera. In past experience, I found that Acera has less chain retention and is a little more snappy. This Altus is a bit more precise and smoother. This makes it an ideal upgrade or replacement. I like the larger lower pulley for the increased chain retention and quiet shifting. Also, like most Shimano derailleurs, it is easy to set up. For the price and quality, I see no problems here. Personally, I don't like the blobs of bright green grease used in the ends of the parallel spring. This is more of a minor annoyance. If you ever do trail rides, you know what I mean. However, I remove the grease with a small flathead and leave a minuscule amount. I wish I could rate this a 4.5 rather than a 4. Overall, it's really good for its quality and price. I highly recommend this for your needs. I will buy again.

Paired this with a Shimano Altus right side trigger shifter, 7 speed. Installed this onto a Mongoose Ardor due to the cheap Pro Rush derailleur binding the chain up real bad when hitting a small jump or bunny hopping a little higher than an inch. Like, the derailleur would skip the chain off one of the pulley cogs and it would stick between the metal guides and the cog. These two, once installed and tuned, are tuned to work perfectly with each other. My derailleur hanger was checked with my Park Tools DAG alignment tool, and the derailleur hanger wasn't really bent hardly at all, but it doesn't hurt to ensure good hanger alignment before installing any new equipment. This derailleur is working fine on the Pro Rush freewheel 7 speed gear set, since it's paired with its proper Shimano Altus shifter counterpart. That's where people mess up, is pairing a new derailleur like this Shimano with the older shifter like the Pro Rush that was on the bike. I'll update the review if the Shimano Altus just breaks or craps out, but the first ride out it shifted very very nicely, and even handled several little jumps with no chain slippage or binding. I just am not ready to upgrade the rear wheel to a free hub with higher than 7 speeds, so finding this derailleur and shifter combo worked out great. :)

The derailleur is awesome and sleek love the design and image it has on my bike along with my other shimano altus bike parts that was ordered from Amazon. Very satisfied Amazon customer plus shimano altus bike customer will always purchase again from Amazon very satisfied and happy 😊 customer! Thank you so much! Rob

Installation was quick and easy. It works perfectly and shifts smoothly. At only $17, it is hard to believe that Shimano has a lower tier groupset (Tourney). This rear derailleur works as it should. For this price, there is no need to even try and wrench on your old/bent/beat up one... just replace it! When you do, toss the old one because you will never need it for parts. Just buy another if/when the time comes.

Just got as spare but good quality recommend

Original parts and speed delivery

My bike had an old Shimano Nexus system and it was time for a replacement. This one works responsive and every screw does its job to adjust every part.

Het werkt heel goed en zonder problemen

Boa qualidade