7 speed rear derailleur recommendation
 

Hello,

I am looking for a recommendation for a rear derailleur that is currently available for a 7 speed rigid MTB that uses Shimano index shifters (non-suspension frame, regular 26" x 1.9" rear tire, a top quality or proven derailleur).

I have recently started back into cycling after nearly 1/4 of a century to discover that what used to be the norm, that of a rigid frame MTB, is no longer. It appears that the industry has favored cheap suspension bikes which I suspect has been allowed because of their marketability.

Anyways, I found what I was looking for through Kijiji, a rigid MTB, and needed to replace the damaged rear derailleur. I was recommended an Acera by my local shop, which I find to be of poor quality. I can only get it to shift perfectly either going up the gears or down the gears; one or the other. As well to this it is hesitant to find its way back into the smallest cog.

Please do not insult my intelligence in reply. The cable and housing have been replaced. The limit screws and cable tension is correct. When removing the cable from the derailleur's pinch bolt it has no problems to finding its way back to the smallest gear. I blame the poor design of the derailleur as I have tried other cheap derailleurs with the same poorly misaligned housing/barrel adjuster to the pinch bolt cable design to discover that there is an unnecessary tension created by the misalignment. The shop where I had taken to replace the derailleur and who had initially installed it told me that this setup, that my 7 speed MTB, are "entry level" cycles which I just assumed them wanting me to purchase a new one with more gears. This was their response to my question of why I couldn't have crisp gear changes as what can be viewed online by people showing the public how to adjust their rear derailleurs; which none of them show with 7 speeds.

The problem I am having is that I live in a remote area and for me to get parts I either have to order them from online or by placing an order with my seasonal bike shop. That means in the off season, October -May, I am on my own to find parts. It is safe to assume I live very far north and in a very remote area. As well to my access to parts dilemma I would like a better derailleur that won't hesitate to go into the smallest cog (2-5 seconds). I can live with not having accurate shifts when coming to a hill as I mostly use the front derailleur for that transition. I am looking for something that has a better design so that the cable coming out of the barrel adjuster is aligned with the pinch bolt (is not offset) so that I can have a more responsive high gear. What I have, the 2015 or 2016 Shimano Acera (unsure as to which year modes it is as it had been opened which I assume someone did not like it or who wanted to see it prior to purchase; the fact that it was in stock), is not as good quality as what I had hoped for and I am hoping to find something that has a better design or just overall a better derailleur.

I had ordered a Shimano TX for $12 off ebay but after 2 months of cycling 1 hour/day (23km) the center of its wheels disintegrated. It worked fine, about as good as the Acera. I noticed that it failed after a recent ride when the drivetrain locked up. It had been doing that for quite some time intermittently and I was able to push through it in the past until one day after unable to pedal through it I stopped my ride, flipped my bike to check it out to discover the problem of my rear derailleur (the Shimano TX purchased from ebay).

*New users aren't allowed to post images*

Unfortunately with this cheap derailleur only the bottom wheel can be replaced because the top wheel has no fastener to remove to get to it.I believe it is riveted or stamped into place.

As well to my question of which derailleur I should be using to resolve my issue of a hesitant shift to the smallest gear, I would like to know if a 8,9,10,11 speed derailleur would work with a 7 speed? I see that there are rear derailleurs with 2 springs (8 or more gears) and that appear to be designed better (allow a correct aligned cable with no offset), but can't tell by the pictures.

This one will work well for your application: https://www.amazon.com/dp/B0165T3AXI/

In my experience, much better than any Shimano for less than twice the price. I have used this RD for 5, 7 and 8 speed applications to date.

EDIT after re-reading your post.
You may also have a worn out shifter. If the 7 speed index shifter is original to your bike, it likely needs replacement.

7 speeds was 80s~90s era..

rear derailleurs don't have "speeds" , they just go in and out ..as the cable pull demands.. its the hub with the (cog Count) 'speeds' and the shift lever with the clicks..

trick is you have to sync the lever clicks with the cog spacing...

Know.. friction shifting makes most any combination work

Please do not perceive insult where there is none.
Don't think 7 speed Dura Ace is currently available, however there are many millions of 7 speed Acera and Altus (lower than Acera) derailleurs still shifting perfectly after decades in use. Maybe check your setup and installation. Good luck.

Any 6-9 speed SIS Shimano mountain bike RD will work (Tourney, Acera, Alivio, Altus, Deore, LX, XT, XTR). Anything Mt. that says Dynasys or is 10 speed or higher won't.
Rapid rise means a "low normal" and the shifters will work opposite of a "high normal" (where the RD defaults to without cable tension)
IMHO LX is the spot of value/$$

6-10 speed road will also index but won't have a long enough cage for Mt gearing. FD only mountain series.

Make sure your RD hanger is aligned properly.

Flush your shifters before you think about replacing.

Yes, any Shimano 7-8-9-10 speed road series rear derailleur will work with your shifters.
It's important to select an RD that can handle your gearing setup, so OK to use a regular road RD (10, Ultegra, etc.) if the largest rear cog is no bigger than a 28 and you are using a double crankset.
If larger than that or using a triple crank, might as well go for a Deore RD- any of them through 9 speed will index properly with your shifters. Plus, they are built for off road use and are super sturdy.
Easily obtained through eBay at a very reasonable price, shipped to your door.

I think that you may be on to something here. Older shifters can become sluggish as grease in the mechanism congeals over time. This particularly affects shifts from larger to smaller cogs. Incidentally, Acera derailleurs are fairly good quality and should function very well if other shift components are up to par. As well, and Shimano rear mountain bike derailleur designed for up to 9 speeds should work perfectly on the OP's bike

I second the derailleur hanger alignment.

Also note that Shimano suggests that the center of the pulley be aligned with the outside edge of the small cog when setting the high limit screw.

I used to set it center to center for years before I watched the Shimano video on RD setup.

Oh, bigger problems than der quality or barrel-adjuster-cable-anchor-alignment.

"the drivetrain locked up" Depending on the situation, that sort of problem could destroy any rear derailleur no matter how good it is. If you notice a problem during a ride and simply push through it without figuring out why that happened, eventually you won't be able to push through and a component will fail. In that case the problem that caused the derailleur failure may not reside with the component that failed.

Lockup sounds bad alright. Check chain length perhaps.

Check for twisted chain links (due to power on shifting?). Andy

This indicates to me that the problem isn't with the rear derailleur but is more likely a worn out or broken shifter.

Try a set of SunRace SLM-10 friction thumb shifters. Costs $10 or less and includes some functional cables and housings. If your existing derailleurs work with those thumb shifters, the trouble was probably with the old STI shifters.

The early 1990s Shimano STI thumb shifters on my old school MTB broke within the past couple of years -- looks like the bearing surfaces wore just enough that the pins popped out. Not worth the hassle of repairing. I replaced them temporarily with those SunRace SLM10 friction thumbies while deciding on a new handlebar and better shifters. Now the bike has albatross bars and bar-end shifters in friction mode -- I used a MicroShift cassette that wasn't perfectly compatible with the Shimano shifters and derailleur, so friction mode was easier and works fine.

Also, my old Shimano Exage 500CX could be adjusted enough to upgrade from 7-speed to 8-speed cassette. I had to change the spacing a bit to be sure the rear derailleur could swing enough to cover the 8-speed range but it works fine. Otherwise I'd have gotten an Acera or Deore long cage RD. Very affordable via Amazon, Jenson USA and many others. Even the Altus derailleur is functional but cheaply made with some slop -- good enough for my errand bike with RevoShift twisty grip shifters, but I wouldn't put Altus on my city bike.

I've got a bunch of old 7 speed bikes that I keep running. This is my favorite rear derailleur : https://www.amazon.com/SHIMANO-RD-M5...ear+derailleur

I keep an eye out for sale prices. I never pay more that about $30 - $35 for one.

I am a fan of the late 1980s/early 1990s Deore LX/DX/XT rear derailleurs. I look for them at co ops, or seek out donor bikes. I also avoid any of the rapid fire shifters out there, instead either using vintage thumb shifters, or the Tourney 7 speed shifters. The sets like the one below usually come with all the cables and housings. Good deal, although I have seen them at times as low as $10.

I've got several 7 speed MTBs from that era, and have provided friends with several more.

Now if you have to buy the vintage stuff on eBay, then the price does not merit it.

Now functionally, even the cheapest Shimano MTB derailleurs work fine.

Live in a remote area? Do you ever go on vacation or a road trip? Thats when I find most of my stuff. I do not find it locally.


Found a bike with a damaged rear derailleur? +1,000,000 First thing to check is a bent derailleur hanger. IME, do not trust that it "looks" straight. Looks can be deceiving. A good shop can check your hanger for very little.

https://www.amazon.com/INKESKY-Shimano-Tourney-SL-TX30-Shifter/dp/B07G776FP6/ref=sr_1_4?ie=UTF8&qid=1546437857&sr=8-4&keywords=tourney+7+speed+shifters+tx30

Thanks for the responses. Had I been able to post the original picture and the original message the reader would have seen that the worn wheel of the rear derailleur was pushed to one side, allowing the chain to bind between the cage and wheel. In this case the picture could have relieved everybody's expectations of continuing to diagnosis the problem instead of just responding to my request for a recommendation for better gear. It is safe to assume that a bike designed to be used with gears may work better for the obvious reason of .....

I didn't want to write a book but originally the Acera was installed by the shop that I had purchased it from; with poor shifting both up and down which I resolved to my preference since I could use the front derailleur. My next post will hopefully include pop-ups for those who are in need of a better understanding. Yes the shop checked the alignment of the hanger the first time when I brought it in for the Acera to be installed, and everytime after when I brought it in to complain that the shifts were not crisp and were hesitant. A hanger is durable, or at least my frame is. Unless a car side swipes me or I take off the rear wheel and drop it a hanger is not going to become out of alignment or have any distortion.

This is the exact derailleur I am referring to that I had ordered in hope to find a better one than the Acera, but had the same results until the wheels disintegrated.

http://www.ebay.com/itm/Shimano-RD-T...fRLH:rk:5:pf:0

I now notice that the current derailleur I am using has a center that is mostly metal. Sure wish I could have posted the picture. The center of the wheels of the one above bought from ebay are about 1/2" dia worn, there is a big hole 1/2" in dia in the center of each wheel. You can see in this add how the top wheel can not be accessed to replace.

Unfamiliar with how derailleurs limit screws worked of the ones that are rated for 8 speed and higher I thought it appropriate to include the description of 7 speed derailleur in the original post. If a higher rated speed derailleur would work I question why it wouldn't state. The one that I am currently testing is rated for higher than 7 speeds and its limit screws does meet my needs.

Currently I am testing another derailleur from ebay ( I bought a bunch of different ones at the same time) that I had hoped would have been suitable but that has failed http://www.ebay.com/itm/Bike-Cycling...sAAOSwJwpZwKzV The barrel adjuster feels good in the hand but its shifts are hesitant and getting it to shift back into the smallest gear is pointless. Only after minutes of shifting into the smallest gear will it react. I had replaced the index shifters with no difference (with both pod index and brake/shifter index). There is subtle difference between using the different shifters with only one constant, poor response between shifting gears and difficulty getting the chain back into the smallest gear with the ones that had the problem to begin with.

I do use a triple pre-stamped crankset which I believe to be 48-38-24 and the 7 speed is 12(smallest) and 28 (largest).

I had a vintage Raleigh with original equips that gave the same problems as the Acera RD, poor unreliable shifts. It had Alivio 10 type components originally. The original shifters were worn and I replaced all of its original worn components (front derailleur didn't need but I did it anyways because I didn't like the pinch bolt location), leaving me with more parts to play with for my current. I had to chuck it at the beginning of last fall because the frame had been falling apart because its frame was rusted out and had finally rusted through behind the BB on the drivetrain side. The parts stripped form it were only two years old from riding an hour a day, nearly every day, which I assume they are fine as they work as good as when I had ordered them.

I believe that story is over. Now just gotta use what has been given on this post to see which will work best for my needs.

I want to thank those who did respond to my request for help. I will, as usual, begin with the cheapest and work my way up, in hope to find the right fit for my MTB. I had seen derailleurs with dual springs but I don't see any in the list recommended. I had thought XT would have been the best choice because that was the rage in the late 80's but thanks for steering me in the right direction. It would appear what I may end up with is a Deore LX 9 speed, if by the time I get to ordering from that price range the frame for this MTB hasn't rusted through.

Cheers!