I have trek bike and use it occasionally. My rear derailleur is broken and part of it hanging. I tried it put it in but it doesn't hold on anymore.
Please suggest if it can be easily fixed or need to take to a bike repair shop. Added some pictures
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
rd-m360 is the one in my link. it will work on 7,8 speed
you can look on the back plate to see what yours is. It will start with RD-
there are others that will work too. just happened to see this one on ebay.
It is a decent price, you could even go alivio if you want to spend more money
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
Could just be a trick of the photo, but your derailleur hanger looks bent in to me (part of the frame that the derailleur screws in to.) If that little threaded tab on the frame isn't perfectly vertical you may want to check it or have it looked at. It will make it very hard to get your gears adjusted if it is bent.
can't tell from the pictures - we are talking hundredths of a mm off at the hanger. Hanger alignment tools register off the rim, which in your case is 280mm away from the hanger, and is easy to adjust to within 1mm of the rim. 3mm off at the rim - 0.01mm at the hanger - results in very rough running.
Nigel