# Can't get the rear (Shimano) derailleur adjusted right



## jimigunne (12 Mar 2016)

I am trying to get my sons. mountain bike to shift right. It is a 21-spd Hyper Havoc P005 series 21 spd. It sat unused for around 3 years. I finally got the left 3- spd shifter working good. Now the rear derailleur doesn't shift. I thought that the cable was rusted and stuck, but not really. I thoroughly doused all teh shift cables, shifters, and derailleurs front and back with PB Blaster. If I have a lot of slack in the rear shifter cable, I can then run the shifter through 6 clicks to the seventh position and back, no problem--- the cable is going in and out freely as seen at the exposed part of the shift cable in middle of the top tube. So there is no binding at any point from middle of top post to the shifter itself! Also, if I release the chain from the gear cluster, I can pull on the shift cable at that same place where the cable is exposed in middle of the top post, and the derailleur will move from full out to full in, no problem. The derailleur spring has sufficient tension to make the derailleur pop back out ok when you release the cable. 
This would seem to prove that no part of the system--- from the derailleur to the shifter--- is bad/binding. But when I go to the lowest gear setting /full slack on the shifter, set the chain on the outermost /lowest gear, then adjust the cable so the derailleur is in straight alignment with the sprocket, and tighten the cable nut down at back of derailleur, then the shifter cannot move the derailleur! I might get 1 click toward more tension, that's it. In case it was the chain engaged on the small sprocket that was preventing movement, I had a helper pull the chain off the sprockets while I then tried to move the shifter through the gears, but it still would not move. If I then manually pushed the derailleur all the way in, like to high gear position, and then tried to move shifter to low gear, the shifter still would not move. So it seems that the shifter just does not have the power to re-position the derailleur. But I already checked the derailleur, and it can move freely all the way in and out. What could be wrong? it makes no sense. There is quite a bit of spring tension on this derailleur, but there has to be, to make it pop back out when tension is released, and I see no way to adjust it anyway. Solution? Throw it in the trash and buy a new one?


----------



## tincaman (13 Mar 2016)

There are loads of YouTube videos on this subject.
Your text is slightly confusing, its seems like you maybe doing the opposite way around to normal, have a look at this and then come back and tell us how you got on?


----------



## jimigunne (14 Mar 2016)

Yea, I have high gear and low gear reversed. Sorry, the "top of the casette" is low gear actually. I think I will probably switch to a new Shimano switch-type shifter. Thanks, I will figure it out by watching youtube videos on the procedure. (I hope)


----------



## fossyant (14 Mar 2016)

Try new cables first.

If the mech moves freely without a cable attached it's not that. With the outer cable removed and the inner just attached to the shifter, pull lightly on the cable, then shift gears. If the cable is moving freely as you change gears on the shifter, it's not the shifter.

Revoshift and Grip Shift need good cables. Cleaning them isn't enough. You should replace cables. You ideally need shimano ones with the PTFE coating/liner - make sure you get gear cables and outers.

Even if they look OK, I bet they are not. I bought my daughter a brand new Carrera MTB, and the rear disc brake was dragging. I replaced the brake cable for a quality one and it worked fine.


----------

