Derailleur Problem

[Sparks2056]

Now I have a much bigger problem. I just got back from a little ride and could not peddle my bike at all. Makes startin out kinda sucky. My rear derailleur is continually popping my chain off. It keeps shifting to a gear even lower than 1. And the chain gets caught in between the gears on the rear wheel and the spokes of the rim. (IF you haven't noticed, I don't know a lot of the "technical" terms of bikes, so bare with me and I'll describe it best I can.) I stopped and took a look at the derailleur arm and adjusted it all the way and when I got to where the screw wouldn't go in any more I noticed that the top of the arm where the chain goes onto the little gears in the derilleur was bent. A lot. I don't remeber running into anything that would have bent the arm like that, so I'm really not sure how it happened. The best Idea I have to take care of this is to get rid of the derailleur arm, shorten the chain, and just have a 1 speed bike that I can at least peddle to get started.

 

[Abeagle]

I hope I explain this clear enough. The rear derailler has 2 screws for adjustments, 1 marked L and the other marked H. The L adjuster screw is used for adjusting the max distance that the derailler will move as it goes to the lowest ( 1st ) gear. This is the one that you will need to adjust in to limit the over shift you are expereincing and run the chain inbetween the spokes and gears.. Adjust it in, in 1/4 turn increments until you get the over shifting to stop. The H adjuster screw is used for adjusting the max distance that the derailler will move as it goes to the Highest gear. it to should be adjusted so that the chain does not over shift and run the chain inbetween the frame and gears. The is one more unmarked screw on some deraillers that id used for adjusting the spring tension on the tensioner, sounds like you might have adjusted that one.

 

[Sparks2056]

the derilleur was bent. A lot.

I had read how to adjust them and understood it, the derailleur was bent and could not be adjusted.

 

[turkeyssr]

There are derailleur alignment guages, but in the meantime check this link out:
http://garynuke.homestead.com/derailleur.html
Lots of pix

 

[SirJakesus]

If the derailleur got bent from a fall or something the only thing you can do is take it off and heat that part of the frame or derailleur that got bent out of shape. Or get a new one. I bent my frame before in a large wipe and had to heat the mount and bend it out.

 

[bluegoatwoods]

There's an advantage to doing away with the derailleur altogether; the extra room you get for adjusting the axle back and forth will allow you to adjust the engine chain nice and tight. So you can do away with the engine chain tensioner. That's what I've done. (brand new build. only about 24 hours old. so I don't know what tomorrow will bring. but it seems to be working.)

easier starts. having only one pedalling gear is a small price to pay for it.