Bicycle Mechanics - Bike Rear Derailleur Broke, Need Help Replacing

Well, I bought a Schwinn bike back a few years, and well today, riding home from school, I switched to a lower gear, and then BAM, my derailleur broke.

Well, I'm a complete bike NEWBIE but from what I know about my bike is:
7 speed
MF-TZ07 multiple freewheel
RD-TX70 derailleur

Well I need help finding a new high quality derailleur. Price doesn't matter. Thanks.

Do you use it just for going to school? If such is the case, any low end shimano RD will do the job just fine. Look for the Acera or Alivio Rear derailers. They are inexpensive and reliable.

Ricardo

I should think price would matter. Why (so to speak) buy a $100 part for a $100 bike? Buy to the level of your bike unless you are planning a build in the very near future.

Well my bike cost about $300. And Ricardo, can you help me find one online that's compatible with my parts? I am a complete biking part newbie.

You really don't need an overpriced derailleur unless you need precision shifts for racing. Most of what everybody has is overkill. The derailleur on my 25 year old Raleigh Super Course was bent and had to be replaced. So I figured the shop would replace it with a 105 or Tiagra. When I saw he put on a Sora I was a little disappointed thinking it wouldn't work all that well. Well much to my surprise it shifts very smoothly better than the one that came with the bike was new. The bike has friction shifters and probably they are less of a challenge to a derailleur.

Well can anyone help me find a good one that's compatible with my bike? I don't want to stick with tourney derailleur.

Well I need help finding a new high quality derailleur. Price doesn't matter. Thanks.

Well, then, a 1980's NOS NIB Campagnolo Super Record/C-Record would look great on your Schwinn. Check Ebay.

If the derailler broke when you shifted into bottom gear, my guess is that the hanger at the rear drop-out was bent. You should get the local bike shop to check the alignment before you break your new one. Search for prices on the Nashbar website, and adjustment instructions on the Park Tool website.

If you have any shops that sell used parts, you might be able to get one for next to nothing. Pretty much anything should work. I recently picked up a 9-speed 105 derailleur for $20.

Well can anyone help me find a good one that's compatible with my bike? I don't want to stick with tourney derailleur.

Why not? You have a cheap bike. Putting an expensive derailleur on it would be a waste of money. A tourney derailleur is about $10-$15. If it lasts three more years, you buy another. But chances are that three years from now, you won't be riding that bike.

all deraillers are fine when adjusted properly, the change in price comes from using better materials/ making it lighter.

all deraillers are fine when adjusted properly, the change in price comes from using better materials/ making it lighter.

I don't agree with this completely. All derailleurs shift properly when adjusted properly. However, I have found higher end derailleurs to shift more smoothly, especially under load.

I don't agree with this completely. All derailleurs shift properly when adjusted properly. However, I have found higher end derailleurs to shift more smoothly, especially under load.

Actually, I think that derailleurs work best when they match quality of the shifters. Low end shifters have a little slop built into the detents that allow you to overshift a scosh to match the imprecision in the derailleur. The upper end shifters don't have that overshift capability and the better derailleurs don't need it.

As you are new to bike repair, I suggest that you just go into a shop and ask for a reliable 7 speed compatible rear derailleur. They will make sure it works, install and adjust it. It should be a cheap part.

As you are new to bike repair, I suggest that you just go into a shop and ask for a reliable 7 speed compatible rear derailleur. They will make sure it works, install and adjust it. It should be a cheap part.
Good suggestion. If you have a bike shop fix it, ask the mechanic if you can watch so you can learn. The guys I go to take the time to explain what they are doing, it helps me quite a bit.

Well, then, a 1980's NOS NIB Campagnolo Super Record/C-Record would look great on your Schwinn. Check Ebay.

Then he'd look like all those 1980's [sic] dorks who thought replacing the rear derailleur on a crappy bike would make some kind of difference.

Talk about retro!

I second Alivio. I put one of those through a few thousand miles and 2 Wisconsin winters and it was still going strong.

If money is no object, just have the LBS do the work. Low and medium-end derailleurs grow out of the ground like mushrooms after a long warm rain.

Or, buy it here and install it yourself: http://www.jensonusa.com/store/product/RD406A02-Shimano+Tourney+Rd-Tx70+Rear+Derailleur.aspx