Bike Forums

Bike Forums (http://www.bikeforums.net/forum.php)
-   Bicycle Mechanics (http://www.bikeforums.net/bicycle-mechanics/)
-   -   terrible problem with rear derailleur (http://www.bikeforums.net/bicycle-mechanics/937272-terrible-problem-rear-derailleur.html)

jonnymc 03-08-14 09:46 AM

terrible problem with rear derailleur
 
Hi Everyone,
got a real problem with rear derailleur, which i cant fix. when the chain is on the largest sprocket, one click of the changer makes it jump to the 3rd sprocket, missing out the first, and its the same problem when coming back up. Any ideas on how to fix this?
Thanks

BikeAnon 03-08-14 10:09 AM

Welcome! Give us details on the model/type of der and shifters.

The setup PDFs on Shimano's site are great. You follow the steps to get things set up, and everything just plain works.

FBinNY 03-08-14 10:46 AM

You have to be more clear in your description.

Just guessing you mean with the chain on the outer chainring (up front), you're having the chain skip the 2nd smallest sprocket and jumping from the smallest to the third.

If so, it could be a simple trim adjustment using the barrel adjuster on the RD. There are plenty of turorials on how to adjust the RD so I'm not going to reinvent the wheel here. But I suggest that it's possibly related to a slightly bent hanger so before simply adjusting take the extra step of checking the inner gear limit. Do so by hanging the bike or having a friend hold it up while you turn the pedals and shift to low by pushing the inner body of the RD all the way in. It should be impossible to push so far that the chain shifts over the top of the innermost sprocket.

lopek77 03-08-14 11:22 AM

https://www.youtube.com/watch?v=g_bG...e_gdata_player

Google or YouTube for more...there is a lot of helpful resources online. I hope its an easy fix for you. Good luck and let us know.
[video=youtube;g_bGcuezsIo]https://www.youtube.com/watch?v=g_bGcuezsIo&feature=youtube_gdata_player[/video]

cny-bikeman 03-08-14 11:56 AM

For clarity's sake the items on the rear cluster (cassette or freewheel) are called cogs and the front are called chainwheels or chainrings. "Sprockets" is too often used for either and is therefore confusing. If you are saying that the chain skips over the 2nd largest cog in the rear when shifting in either direction yours is not a simple adjustment problem. But what you said is not clear, because you said it jumps to 3rd cog, missing the 1st - seems like it should be the 2nd it's skipping. Please use smallest, largest, 2nd smallest instead of 1st, 2nd etc. and explain the problem again. Thanks.

icon_cycles 03-11-14 03:53 PM

It could be that the shifter and derailleur are not compatible if one of them is new. Some Sram parts will not work with Shimano as the activation ration is different.

ickyicky 03-14-14 10:57 PM

If you have a replaceable hanger, be sure it's bolted on tight. I had a weird skip from 7-5 that was caused by that.

dabac 03-15-14 12:36 AM

Quote:

Originally Posted by cny-bikeman (Post 16560136)
For clarity's sake the items on the rear cluster (cassette or freewheel) are called cogs .

I don't like that. Cogs engage other cogs, sprockets engage a chain. The only ones who'll regularly call chainrings sprockets are the BMX crowd, and possibly some reformed motorcyclists.

3alarmer 03-15-14 01:14 AM

.
.
...terrible problems: My dog died, I'm being evicted, my wife wants a divorce, some ****er stole my bike, I have a terminal disease.

....relatively minor problems: my rear derailleur is out of whack.

lopek77 03-15-14 02:11 AM

Quote:

Originally Posted by ickyicky (Post 16579247)
If you have a replaceable hanger, be sure it's bolted on tight. I had a weird skip from 7-5 that was caused by that.

It's an excellent tip that I didn't see in any previous threads I saw so far. You right...that bolt likes to get lose from time to time, and it will create shifting issues.
I keep forgetting to put some Loctite threadlocker on that bolt.

cny-bikeman 03-15-14 05:10 AM

Quote:

Originally Posted by dabac (Post 16579345)
don't like that. Cogs engage other cogs, sprockets engage a chain. The only ones who'll regularly call chainrings sprockets are the BMX crowd, and possibly some reformed motorcyclists.

Yes but convention usually trumps accuracy. Sheldon didn't like the spelling of derailleur, but that did not change it. I wasn't saying one should use "sprocket" - the opposite. I said it's used too often.

xenologer 03-15-14 05:33 AM

Quote:

Originally Posted by cny-bikeman (Post 16579521)
Sheldon didn't like the spelling of derailleur, but that did not change it. I wasn't saying one should use "sprocket" - the opposite. I said it's used too often.

...well I call it a derailer...



assuming OP is correlating size with numeric indicator on shifter display
such behavior of skipping 2nd is common with a 'megarange' freewheel and rear derailer bent inwards

cny-bikeman 03-15-14 06:25 AM

Good point, but the problem is that the answers here contain words like "assuming" "just guessing," "could be" etc because the OP has not come back to clarify. Garbage in, garbage out.

HillRider 03-15-14 06:20 PM

Quote:

Originally Posted by 3alarmer (Post 16579377)
.
.
...terrible problems: My dog died, I'm being evicted, my wife wants a divorce, some ****er stole my bike, I have a terminal disease..

Sounds like the lyrics to any number of Country & Western songs. :rolleyes:

curbtender 03-15-14 06:41 PM

Quote:

Originally Posted by HillRider (Post 16580953)
Sounds like the lyrics to any number of Country & Western songs. :rolleyes:

Charles Barkley "That's Turrible." - YouTube


All times are GMT -6. The time now is 01:09 PM.