Bicycle Mechanics - Shimano Tourney rear deraileur identification + information?

Hi, my Shimano Tourney derailleur needs replacing - could someone help me identify which I have? Also, what are the differences between TX35, 55, 75 and so on? Are they specific fits or do the numbers denote a higher spec derailleur?

Link to picture here: https://www.dropbox.com/s/cmmx4w0xjoqax7g/2012-06-14%2013.22.02.jpg

255917

Thanks!

Based on the pics this looks like a lesser Shimano long cage with a claw hanger. So most any decent long cage Shimano with a claw hanger new or used made in the last 20 years or so should work as a replacement.

Replace that bit of cable housing while you're at it; it's got quite a kink in it.

The model code is stamped into the back swing plate e.g. RD-Mxxx. Shimano Techdocs gives diagrams (EV = Exploded View) and SI = Service Instructions.

Replace that bit of cable housing while you're at it; it's got quite a kink in it.

It also looks like it was too short.

Yes, and it looks like there is a derailleur hanger on the bike, so virtually any of the Shimano mountain derailleurs will work. Altus, Acera, Tourney, Deore.

Looks like an RD-TX31 to me... Some of the other tourney derailleurs have a pulley where the cable goes in, though I'm not sure what purpose it serves, if any. I think as has been said any shimano mtb derailleurs should be fine, they can all handle a big enough tooth difference.

That said, although this is a 6/7 speed one, using say a 8 or 9 speed shoudn't be problem should it?

Looks like an RD-TX31 to me... Some of the other tourney derailleurs have a pulley where the cable goes in, though I'm not sure what purpose it serves, if any. I think as has been said any shimano mtb derailleurs should be fine, they can all handle a big enough tooth difference.

That said, although this is a 6/7 speed one, using say a 8 or 9 speed shoudn't be problem should it?

Good observation. That is a TX31. The 50-series have a pulley on the rear cable adjuster barrel. This version is withOUT a claw mount. It's designed for any bike that comes WITH a derailleur hanger. Only it looks like it needs a claw bracket because it uses a relatively heavy. stamped, black, thin steel tab for the mounting plate and I don't think there is a B-screw for this one. But I've verified it works fine with 8 speeds on indexing using a 6.9mm wide chain. I didn't splurge on a 9 speed chain but the pulleys seem relatively narrow.

I'm not sure if the RD needs replacing. Some lube, and a ft of new compression-less and lined der. cable housing with a fresh cable is likely to get the rear to shift fine. However, remember to check the der. hanger alignment. If the dropout/frame is steel, then it's possible to bend it back slightly. If it's aluminum, it may be hard to find a replacement hanger, or if that tab is integrated into the dropout, like it appears, it may not be easily repairable if bent.

I agree, there were so many "Tourney" derailleur models it's not worth the effort to figure out which one this is. What's important is that you find another one that is compatible with the cassette and that has the required max wrap and max large cog capacity.