live_dont_exist

Hi All,
This is a problem with the piece on the back wheel through which the chain goes. I think that is called the "rear derailluer". So the short story is the following:

- Torker bike. 2012 model. Simple commuting bike.
- Riding on 2nd gear in the front and 5th or 6th in the back
- Change gears, stop at a signal
- Then the light goes green and I cant pedal
- Take bike over to pavement, and the rear derailleur is completely bent at 90 degrees to its position
- Chain wont move
- Bend it back etc... get everything into position again
- Chain moves now but it keeps clicking as if I'm changing gears all the time while pedaling (which I am not)

So basically its still in some bad position and barely functional. I think I'll take it to the LBS but is there something I can start off trying to so. Do you need any more information/pics?

Thanks
Arvind

CliffordK

Put your bike on a stand, or flip upside-down on a soft surface, and slowly pedal.

My guess you'll notice a point in the chain that it is kinked when it goes through the derailleur pulleys. You may also find it by manually bending the chain with your fingers.

Sometimes you can work out the kinks with oil, WD-40, and wiggling them. Is the chain rusted? Lubed?

If you have a chain tool, the middle notch is designed to gently expand the plates on the chain which can help some too (not too much).

If you have a removable aluminum derailleur hanger, it may need to be replaced. And, look up notes on aligning your derailleur hanger.

You will have to adjust the top and bottom derailleur stops after messing with the hanger.

FBinNY 

If it's happening on a fairly large rear sprocket, and when shifting at low or no speed, it might be that the derailleur is high, and hitting agianst the larger speocket and getting pushed back as you start out. This is usually fixed by adjusting the "B-screw" at the back of then upper body. Search "adjust rea derailleur" for tutorials before tinkering blindly.

Other than that, I don't have much to offer because the description of the problem is so vague. But since you're seeing the dealer, let him walk you through the basics.

fietsbob

Questioning the RD , Step !1! Check the derailleur hanger alignment on the Bike Frame dropout. (Bike Shop Tool)

CafeVelo

Based on the fact OP is unsure of what exactly a rear derailleur is, I'm assuming he doesn't have tools or the knowledge to diagnose or repair. I assume he needs an LBS to accomplish much of anything in the way of repair. It sounds like the RD and possibly hanger bent significantly, but didnt break, which is surprising since in my experience the cage rips off the parallelogram pretty easily.

OP: you probably need a new rear derailleur and possibly a hanger for it, if yours is brazed on or part of the dropout you could be fubar if it's too bad, since the alignment tool only gets you so far. You may also need a chain. I didn't when I ripped a derailleur up, but some of the links were bent. Take it to your LBS, expect upwards of $50 in parts, and an hour or so of labor at least.

live_dont_exist

Thank you all for your suggestions.

@CliffordK: I will go buy a chain tool tomorrow, I probably need one anyway. I turned it over and tried taking the chain off and putting it back but it seems to have gotten much harder to do, than normal - when the chain just slips off while riding. I will try again though.

@FBinNY: I have attached a couple of pics. Does that help a bit?

@fietsbob: Sadly, greek and latin at this point. Thanks though.

@CafeVelo: Yeah, I'm guessing its the Shimano attachment at the back which the chain goes through a couple of tiny metal wheels. Basically, that's what is keeping the chain moving on the back wheel. That sounds very expensive though - I needed this bike to last only 4 more odd months .. too bad it conked before that . Hopefully I can repair it or something. Do take a look at the pics though.

If anyone needs nicer pics or more info, please ask me - I'll try my best.

CliffordK

I'm assuming you have your bike upside-down.

Something is seriously wrong with your chain path.

Here is your image, and what the chain path should look like.



Did you take the rear wheel off? If yes, is it back on right? If not, you may need to to get everything unjammed.

You could have bent the derailleur or hanger.

Many new chains come with a "quick link", but I always use a chain tool to install/remove mine. Your may be difficult to remove without a tool.

Anyway, you might either take it into a shop, or find a local bike co-op that might be helpful in explaining how to configure the derailleur. Be very careful of the upper and lower stops which determine how far the chain can shift.

fietsbob

I dont know "Where is a Good Bike shop?" in either of those languages , But google translate did.

Greek: Πού είναι ένα καλό ποδήλατο κατάστημα

Latin: Ubi cursoriam tabernam bonum?

live_dont_exist

Thanks CliffordK. Yeah, it seems awfully bent and jammed up. I guess I will buy a chain tool then. I'll try and fix it like you showed and if not go to a shop. It looks just awful at this point.

fietsbob: . Thanks

Bill Kapaun

If you bent the RDER over 90*, you can pretty much count on having to replace it.
They just don't bend back correctly.

live_dont_exist

@Bill:

I managed to put the 2 "wheels" in the derailleur back as per Clifford K's instructions and took a couple more pics. It looks a little better now, but the things still seems pretty bent. I took a couple more pics after I fixed the chain, anything you guys can tell from them?

If not, I'll just take it to the LBS next week. I did go in there and ask but they said they'd need to look at the bike.

CliffordK

Whew, your pictures look dark and grainy. This is the best I could do.



Either:

• Your chain has fallen off of the chainrings up front.
• Your chain is way too long
• You are cross chained.

The general rule is to go from the big ring up front to the small sprocket behind.
And from the little ring up front to the big sprocket behind.
Obviously using the sprockets in the middle too, but to avoid Big --> big and Small --> small.

However, your chain length and derailleur size should be adjusted so that it is possible to go Big-->Big without tearing the derailleur apart, and small--> small without dragging the chain across itself.

Looking at the first top view photo, it also looks like your derailleur cage is bent (or possibly a bent derailleur hanger). The derailleur cage should be perfectly parallel to the wheel's axis at all points.

You can fix it yourself, but since you're struggling, I'd take the bike to a shop and talk to a mechanic.

live_dont_exist

So just a quick update. I went over to 2 LBS's in the area. Apparently its bad news.

- The derailler has a spring which is busted and is totally bent. Meaning I need a new one.
- The chain is also bent. Meaning I need a new one.
- Now since the chain and the rear sprockets? wear at the same time, I need new sprockets too else the chain will keep slipping off.
- And they say, might as well put a new cable on as well.

All that, as mentioned by @CafeVelo earlier in the thread comes to between 50 and 60$. And around 40$ labour. Meaning around a 100 bucks. If I do it myself, the tools still cost a fair bit - ending up being more expensive. In short, I'm screwed . The overall bike itself was a cheapish bike at around 270 bucks...probably 300 now. So I don't want to spend that much on it, honestly.

All the same, just thought I'd thank all on the thread for their help and let them know the status. Thnx.

CliffordK

Like a car, any bike will require periodic maintenance. It is hard to determine when the maintenance exceeds the value.

You don't have to replace the rear freewhee/cassette with every chain. Perhaps a few chains, and many thousands of miles before replacing it.

Your photos are dark and grainy. It is hard to tell the condition of the parts without seeing them directly.

A good bike can last a very long time. Mine is nearing the half century mark. But, that isn't without periodic maintenance, and I have no doubt that I've spent more on tires than I spent on the original bike purchase.

CafeVelo

I've bent chains back and used them afterwords, you don't always have to replace things. If it's incredibly fubar you do need to change it. Try to find a bike co-op, you can likely get a new derailleur and have it installed for a few dollars. Bike shop prices will be more as I described.

live_dont_exist

So...a bit of an old thread bump (sorry) but didn't make sense to start a new one.

I went out of town etc etc and didnt need the bike but now am back and need it to last for another 3 months . And in the spirit of learning more.. I decided to fix this myself. So went and bought a derailleur... and the kind LBS (as suggested here) just bent the chain back and said it was good enough. So all I need to do is fix the derailleur, re route the chain..and am good.

I tried doing so now....but was having trouble putting the chain back, so thought I'd check if I have the derailleur setup correctly? (Please see image attached) If this is okay...then I'll try doing the chain again.

Thanks