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I replaced the rear derailer on my bike after Schwinn sent it to me. The old one had a bent piece.

I can't shift onto the largest 2 rear gears. I set the shifter to the lowest setting, but the chain won't shift onto either of the 2 largest gears.. It looks like the rear derailer isn't aligned straight with the rest of the bike.

In comparing to another similar bike I have that works fine, I can see that the rear derailer on the properly working bike is perfectly aligned compared to the gears.

Update : I just fixed this (thanks to the suggestions) by tightening the tension cable and also by loosening the H Screw (assuming that is what it is called)...it works perfect now..

update 2 : This question seemed to have got a few views and so updating with some additional information.

The first video sent to Pacific cycles

They were awesome and sent the derailleur (I did not know what this part was called earlier) to me and I put in the new derailleur and then asked this question on stack

I sent the question above to Pacific cycles also and they also replied

with the help of folks here and Pacific cycles I was able to fix this Luckily in my case it was a simple issue

Thanks,

  • Welcome to Bicycles @Naresh. I haven't seen a question posted by video before! It will be interesting to see how it goes. My Gen BB preference is for text, since I can scan it quickly to get all the info, whereas with a vid I have to watch it all, at the pace you set. But most users are Gen X or Gen Y, so we'll see :-) – andy256 Aug 14 '15 at 5:04
  • thx andy ! and agree let us see how folks take it...me personally am hooked to videos instead of typing...yes I understand it might have it draw backs – Naresh MG Aug 14 '15 at 20:00
  • It's pretty hard for people to search for related questions with a video and for people who use mobile devices, the video can add to data usage. It would be good if you summarized the video and put the video there. – Batman Aug 15 '15 at 15:26
  • Good point batman, the search would not work.. I will try and put is some words after I figure out the various part names – Naresh MG Aug 15 '15 at 17:02
  • I edited the gist of the question in the video into the question, with some of the terms. If you don't know the right terms, that's fine; just try to describe the thing or what it does. Questions like that will be found by others in the future having the same trouble describing their similar problem. – freiheit Aug 15 '15 at 21:15
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I didn't see the video but if your talking about the last 2 lower gears you may need to loose the tension cable. if its the top 2 big gears then you may need to tighten.

make sure you derailleur is installed correctly. make sure the last pulley lines up at all cogs especially the biggest one, using your hand and pushing this up and down the cassette, make sure it clears.

try to unbolt the cable, back out on the gears with shifter and back out the fine tune barrel adjuster located on cable/derailleur. pedal, then chain should drop to last small cog. then pull cable hand tight and screw bolt back on cable. make any fine tuning with the barrel adjuster when shifting up.

those are some tips from what I would assume...maybe others can help :)

  • from the video preview, it looks like the hanger is bent? is it? take it to a shop and let them look at it, they probably can solve it in a minute free of charge! – ChineseCowboy Aug 14 '15 at 18:13
  • it previously did have a problem where it was bent as seen here youtube.com/watch?v=MjdlIOJ0PQs – Naresh MG Aug 14 '15 at 20:01
  • I also just got this information from Pacific cycles "It doesn’t look as though your high and low adjustment screws are set quite right. Please see parktool.com/blog/repair-help/… for detailed instructions with pictures for further adjustment instructions."...so have to try it out – Naresh MG Aug 14 '15 at 20:02
  • and thx for the suggestions...I will try out ..and I believe what @chineseCowBoy is saying is same as what Pacific Cycles are saying – Naresh MG Aug 14 '15 at 20:03
  • @NareshMG: I don't think Pacific Cycles watched your video. They're probably right that the adjustment screws are off, but I think the bigger problem is that the hanger is bent. You'll want to straighten the hanger before trying to do any other adjustments. – freiheit Aug 15 '15 at 21:16
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After watching both videos, I believe that whatever bent the rear derailer also bent the derailer hanger, which has your rear derailer out of alignment.

The rear derailer/derailleur is that complicated part you replaced that moves the chain between gears on the rear, and also keeps the chain from getting loose and falling off.

On most bikes, the rear derailer isn't bolted directly to the frame of the bicycle. There's a small piece of metal bolted to the frame of the bicycle, and the derailer bolts to that. That's a removable derailer hanger. Typically the hanger is a softer metal that will bend easier than the frame. It's done that way to help protect the frame from damage if something happens to the rear derailer. Some bikes that hanger is built right into the frame and can't be replaced.

You probably need to bend the derailer hanger back straight. Even if you replace it, new ones often need a small amount of alignment adjustment (bending). Because it's a small piece, it's difficult to bend it back straight just perfectly. In a shop, they'd use a hanger alignment tool which is basically a strong bar that bolts to where the derailer bolts into the hanger, has alignment gauges that are compared against the (trued) wheel, and can be used to bend the hanger back to the correct alignment. You use a large adjustable wrench, like this answer suggests, to bend it straighter, but it's likely you'll have trouble getting it quite as perfectly aligned as your other bike.

Here's an article on aligning the derailer hanger: http://www.parktool.com/blog/repair-help/rear-derailleur-hanger-alignment

While the misaligned derailer indicates a bent hanger, it's also likely that your derailer high and low adjustment screws aren't set right, and/or that the cable tension is off. Those things should be adjusted after the hanger is straightened (so that the derailer is aligned perfectly like on your other bike). The adjustment screws on the derailer are small screws you use to adjust how far it will shift in either direction. The cable tension slowly goes bad over time as the cable housing compresses ("cable stretch"), and can be easily adjusted with a small twist of a barrel adjuster on the cable.

Here's an article on adjusting almost everything else on the rear derailer: http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

  • thx for the detailed reply. I have updated my queustion...but guess the right place is here (as the question is waiting moderation)...I think I am good now...actaully they (Pacific) did send me the whole part with (I am assuming) what is the hanger also. I tightened the tension wire and adjusted the H screw and that seems to have fixed it. once again thanks you very much ! – Naresh MG Aug 15 '15 at 21:45

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