Upgrading the derailleur?
 

Have a ’12 Trek DS 8.3 with a Shimano M191 front derailleurand a Shimano Acera M360 rear derailleur.
Upon replacing the front derailleur’s cable, it seems the derailleurhangs and does not retract under its own spring tension. The derailleur is completely free of debrisand very thoroughly cleaned. The derailleurhas been lubricated after the cleaning leaving only one assumption left as aresolution, and that is to replace it.
My question is, what is the upgrade from the M191? I want to retain the same cable layout if itmatters yet increase the reliability (durability) of the derailleur. Since new, it seemed to have a sloppy up/downshift for the 48/38/28 crank set and if that can be resolved with a better mechanism,I’d rather do that now. The rear derailleuris fine, but if the alignment can be better supported to accommodate a newfront unit by replacing the rear derailleur as well, I am not opposed to thateither. Have an 11-32, 8 speed rear cassette.

Before you start replacing derailleurs, I'd look for something else going on. A front derailleur doesn't suddenly stop working because you changed the cable. If anything it should have helped.

Also, front derailleurs don't generally just stop retracting unless there is something broken. I think you could take the front derailleur off the oldest crappiest Schwinn Varsity from the Salvation Army, and it would at least still have spring tension and probably work just fine.

What happens when you disconnect the cable? Can you move the derailleur by hand, and does it spring back to the inside position? If not, is it "stuck" or is it "loose" (no spring action)?

How is your bike's front derailleur cable routed -- from the top or bottom? The M191 is a dual pull derailleur, meaning the cable can be routed either way. I'd want to know your particular cable routing before suggesting replacements. I'd also suggest, especially since you have a dual pull derailleur, that you re-check your cabling before ordering a replacement derailleur.

Since front derailleurs are pretty simple devices, they don't break often. When they do break, the failure mode is typically apparent. Since this one stopped working when you replaced the cable, the cabling is a whole lot more suspect than the derailleur.

As for "better" derailleurs, high-end parts aren't typically available for 8-speed drivetrains anymore unless you find used or "new old stock" derailleurs from sources like eBay. New replacements are likely to be of the same "a-series" (Altus/Acera/Alivio) quality level as your original derailleur. They're reliable parts, though, especially for something simple like a front derailleur.

This one?

https://www.amazon.com/SHIMANO-Alivi.../dp/B00BQ7UGVO

Have to make sure you get the right size clamp of course. Of and they tend to have difficult configurations depending on where the clamp lies compared to the shifting mechanism, called "top swing" or "bottom swing". Just try to buy one that looks like your old one.

I agree, a FD is a cheap part, if it's giving you issues, just replace it.

I am going with the later FD used on new 8.3's. It's a Tourney, so same level of expectations, just new.


Messing with old equipment is just not wise when cost is minimal.

Tourney is lower quality than what you had on their before, FYI.

Factory, bottom routed. FD is the issue. Everything going to it moves with ease.

That's what I concluded. However, if I were to compare the tourney to what I have now, the tourney might exceed quality over my factory broken one. lol

This what You Have? https://www.evanscycles.com/shimano-...riple-EV175165

there is top swing types that pull from the bottom. too..

Well of course any FD is better than a broken FD.

Personally Alivio is as low as I'd want to go in Shimano mountain parts, as the cost savings of going lower are minimal usually. Heck, for a front derailleur you can usually get a Deore one for $20.

That one looks like the 2015 Trek model. Similar to what I am going with, yet there is something different about that one compared to one I am putting on now to replace the original one. Don't have it in front of me to see exactly what is different. I may just need more coffee to wake up and realize it is the same one bought. lol

For the cost, I agree. I would have went balleriffic and purchased the most bedazzled FD I could find (within reason) .
Due to current events, went with supporting a lbs by picking up a run of the mil FD that works as intended. Little higher cost B&M vs online, but same day part in hand over a minimum of a week shipping time.

Certainly that's a fine reason to go with the FD you bought.

Please excuse me if this isn't it.

Examine where your shift cable attaches to your front derailleur. Sometimes there's a little finger there perpendicular to the cable. The shift cable has to go OVER that finger. If you route the cable under the finger it'll make it real hard to shift.

Your other advice is solid but not this. There is no need to stick with an "8 speed" front derailer. It doesn't matter. A 9 speed or even 10 speed front mountain bike derailer should work just fine. You can mix and match as necessary.

While the Tourney is a bit too low in quality...Acera or Alvio would be a better choice...Shimano's front derailers don't improve with cost. If anything they get more finicky as you get to the higher levels. Alivio or Deore are good front derailers that are relatively easy to set up and keep running properly. The higher end stuff like XT and XTR (this holds with road front derailers as well) are horrible! Shimano sculpts the higher end derailers like they are Michelangelo and the derailer is an 17' foot tall piece of Carrara marble. It's way over the top and makes the derailer difficult to adjust properly so as not to be rubbing in lots of combinations.

Since you want to replace it, I would change brands entirely. Shimano's front derailers are generally awful in my opinion. They just try too hard (see above). Sram's triples are far superior to the Shimano's in function and in set up. It doesn't matter which level you want...X5 to X9...they all work flawlessly and with more positive action than anything from Shimano, even with Shimano shifters.

FWIW, went from the oe m191 to the tx51. Only put the x51 on without aligning it, and now the FD extends out and retracts smoothly. Tomorrow I will try to get back early to adjust it and then, well... test it out! :D


Thanks all!