Trouble with rear gears

[DCBassman]

It looks twisted out of line to me...

 

[gazza81]

I dont think thsts the best picture tbh, i think the chain was in the second smallest cog while the mech was in the smallest.
Just how i left it after getting fed up with it the other day!
I'll do a better pic

 

[raleighnut]

I cant see where its bent? Or what part of it needs straightening
Think im going to have to give in and take to a shop

It's not the mech that's bent it's the bracket that attaches it to the frame which is called 'the dropout' which has become deformed.These are designed to deform to save the derailleur from damage in a knock and are easily realigned with a tool or replaced if they are too badly bent. Oh and if you fit a new one then that will also need to be aligned correctly when fitted.

 

[raleighnut]

Best vid I can find,


View: https://youtu.be/hiebZLLn0h0

 

[confusedcyclist]

If you've ruled out insufficient cable tension, derailleur hanger alignment tools are cheap and accurate. As others have said, start with this task, otherwise you other attempts to adjust tension, limiter screws and cable clamping may be in vain and need repeating if the derailleur is realigned later.

Your hanger might get knocked out of alignment if you drop or lean your bike on the drive side, or it takes a whack at a bike stand, etc. You want to be confident you are starting from a clean slate when troubleshooting these issues, especially if it's not just something you've done wrong after tinkering. If you don't have the tool, borrow or get one! Get a cycling maintenance book and follow the rear mech setup to the letter, ideally with new cables and you'll know that if you still have the problem, it's got to be an issue with the mech itself. It may be worth lubing the moving parts of the derailleur. Salt on roads this time of year can lead to the springs seizing, in which case, heavy dose of lube and manual manipulation might work it out, but in most serious cases, you'll need to replace the mech. This of course, should be your last resort.

 

[gazza81]

Ok thanks guys now i think i can see it!
I will look at getting a tool or making one and have a go at bending it back

 

[gazza81]

So just to make sure im right, the bottom arrow is the dropout, which does look bent but also the top arrow where the frame is does that also look bent? It does a little to me...

 

[Smokin Joe]

Compare this cable run to yours -

 

[gazza81]

Compare this cable run to yours -

View attachment 496267

Yeah i know what you're saying but it really does look like its suposed to be where it is, you can see the grove for the cable to follow

 

[raleighnut]

Compare this cable run to yours -

View attachment 496267

Same as mine although I'm using friction shifting on that bike.

 

[gazza81]

Right ive straightened it up, still cant get it changing great though, but it is better.

I can get it to go up the cassette turning the cable retention as needed but when in the biggest cog it will come down 4 or 5 gears but then wont come down anymore untill i loosen the cable retention, once i do that it will go all the way down...but then it wont go back up haha

 

[roadrash]

when you say...Right ive straightened it up,...…...what did you do exactly

 

[confusedcyclist]

Unless you used an accurate tool, you won't know if it's in alignment. Then we are wasting our time! Even if the hanger is perfectly straight, it might not be in alignment with your wheel/cassette.

 

[screenman]

when you say...Right ive straightened it up,...…...what did you do exactly

Bent it a bit I guess.

 

[gazza81]

Hahaha well, i bent it with an adjustable spanner, used a straight edge on it and it looks alright to me?