schwim

Hello everyone!

I would like to swap out the current derailleur for a better model. I found some Acera SGS that I'm pretty sure is compatible with my Tourney 7 spd brake/shifter combo lever. I wonder, however, what would be considered a great upgrade part number in this case?

I know I'm just dealing with NOS stuff at this point and it's not so much a relevant setup any longer but eBay seems to be great at keeping me in parts so I thought I'd just through a few PNs at it and see what I can find.

Thanks for your time!

Iride01 

What are you trying to solve? Does the current DR not shift well?

Not sure that any you replace it with will be an "upgrade".

Bill Kapaun

I wouldn't go beyond a DER rated for 8 speeds.
As the # speeds increases, cages get narrower and things like chain rub become more apparent.

Even a Tourney should work adequately for 7 speed if maintained.
Cleaning & lubing the cables may seem like an upgrade?

schwim

Slow to shift and the pressed steel cage is so flexible and sloppy that it flexes in cross-chain situations. The plastic cogs are so loose, they go cockeyed on their axles. It's a pretty crappy example of a derailleur.

Thanks very much for the help. The one I linked is a 7/8 speed der and if I remember correctly, the Acera was a pretty decent Shimano line. I'm not familiar enough with either road-specific gear or the era to know what was above that.

The cable system is a new Jagwire set. Shifting is nice, the tolerances are just so poor on the rear der that it makes it impossible to dial in.

Thanks very much for the help!

CliffordK

I'd probably choose up to 9 speed. Possibly even 10 speed.

Ultegra 6500 and 6600 are good derailleurs.

That appears to be a reasonably small rear freewheel. So, you could choose some MTB derailleurs, but you may not need a super long cage.

Jeff Neese

That Acera derailleur would be a fine upgrade, and perfectly compatible with your shifters.

veganbikes

I probably wouldn't put any money towards that bike, save up for something that is going to be more practical for your usage. Yes overall an Acera is an upgrade from what comes on it (even though Acera is lower end Shimano) but the bike overall is probably not worth the time and effort and cost of installing a new derailleur. Generally if the bike is coming with random tourney parts not typically found beyond those bikes the entire package probably isn't worth putting much money into it as it is a losing battle. If it were say a Specialized or Trek or something like that you might have a better case as you will likely have a slightly better frame and maybe some other components around it not by much because Tourney is not a great sign on anything but generally on that stuff it is an overall nicer package not by a huge ton of course but at least somewhat.

One should not cross chain ever there just isn't really a need for it that is the whole point of having two derailleurs. Learning to shift will aid greatly in keeping the bike in shape and not wearing things out prematurely. If you find yourself needing an easier gear and you are at the big ring at the front, you might need to shift down at the front to make it easier and if you are in the little cog at the back and finding you aren't getting enough speed you might need to shift up to that big ring at the front. It is just practice and training your brain and muscles to do it all : )

schwim

Thanks very much for the suggestion, I'll start keeping away from the situation in the future.

dedhed

Never had an issue running 6/7/8 chains through 9 speed derailleurs.

hokiefyd 

An RD-M310 (Altus line) and RD-M360 (Acera line) would both be fine units to replace the Tourney you have, and would be 100% compatible with your current shifters.

You could "splurge" with an RD-T3000 (newer Acera) or RD-T4000 (newer Alivio), but that M360 you're considering should be more than adequate.

schwim

Thanks very much for the help. Installed it today and unlike the one it replaced, it was a breeze to dial in. A huge jump in quality of shifting.