Trouble with rear gears

[Orangey]

Hi, newbie here

The mech doesn't appear to be moving freely on the pivot - when you push/pull the adjustment screw, does the body of the mech swing freely? Very freely? I once had this on a well-used winter bike, the housing where the mounting bolt goes was full of crud. Worth checking.

 

[roubaixtuesday]

That derailleur cable angle... here are pics of my 10 speed 105. Completely different.

 

[Shearwater Missile]

OK. If you disconnect the cable at the RD does the RD go to the small sprocket ? It should do because there is no resistance of the cable. If it does`nt then set up the limit screw to move it into position over the small cog. Once that is done then manually push the derailleur towards the wheel and see it it will reach the large sprocket on the cassette. You may need a second pair of hands unless you have a bike stand. If it does move over far enough then the limit screw is OK, if not then that would need adjusting. This should have been done anyway, sorry if I am teaching you to suck eggs. If every thing is OK at this stage then re-attach the cable and adjust the barrel adjuster to maintain a nice clean silence of the chain over the sprockets. If you still have the problem then it has to down to the shifters but you have already said that you have the correct number of clicks. 105 is really no different to Sora and Claris really, just down to the number of gears and version. Good luck.

 

[Shearwater Missile]

That derailleur cable angle... here are pics of my 10 speed 105. Completely different.



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The angle of the cable does change and gets more acute in the smaller sprockets, I checked on my 11 speed 105.

 

[gazza81]

OK. If you disconnect the cable at the RD does the RD go to the small sprocket ? It should do because there is no resistance of the cable. If it does`nt then set up the limit screw to move it into position over the small cog. Once that is done then manually push the derailleur towards the wheel and see it it will reach the large sprocket on the cassette. You may need a second pair of hands unless you have a bike stand. If it does move over far enough then the limit screw is OK, if not then that would need adjusting. This should have been done anyway, sorry if I am teaching you to suck eggs. If every thing is OK at this stage then re-attach the cable and adjust the barrel adjuster to maintain a nice clean silence of the chain over the sprockets. If you still have the problem then it has to down to the shifters but you have already said that you have the correct number of clicks. 105 is really no different to Sora and Claris really, just down to the number of gears and version. Good luck.

Yep soon as i loosen cable it drops down, even when the cable is in if i give it a little helping hand it will go down, almost like there is not enough pull to drop it to the smallest cog if that makes sence.

 

[gazza81]

When its in the biggest cog the angle is fine

 

[gazza81]

Ive tried taking all the cables out and putting a little grease on them, still not changed anything, tried the cable at different angles, no joy.
Greased all the mech.

Like i say i just cant figure it out, i can get it going easy enough but on the way back down the cassette it stops around the 3rd gear from smallest and have to click twice for it to move, that's why its not going into the smallest when it gets there

 

[Ming the Merciless]

That derailleur cable angle... here are pics of my 10 speed 105. Completely different.



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Your derailleur looks well bashed and don’t you ever clean your wheels?

 

[Shearwater Missile]

Yep soon as i loosen cable it drops down, even when the cable is in if i give it a little helping hand it will go down, almost like there is not enough pull to drop it to the smallest cog if that makes sence.

It sounds to me that there is not enough tension on the derailleur because with the cable removed it would feel a fairly strong pull to the limit screw. With the cable attached that pull should overcome the friction of the cable. When in the smallest gear the cable should be slightly limp and you should be then able to put tension on the cable of your downtube by hand to pull the derailleur arm across. I think that I may have mentioned this in an earlier post. Of course with the shifters it pulls at the right increment of the cable to the next gear. Do you access to another bike so that you can feel the tension on another derailleur spring ?

 

[gazza81]

No wheels arnt clean, Ive not even ridden it yet since i bought it!!!

 

[gazza81]

It sounds to me that there is not enough tension on the derailleur because with the cable removed it would feel a fairly strong pull to the limit screw. With the cable attached that pull should overcome the friction of the cable. When in the smallest gear the cable should be slightly limp and you should be then able to put tension on the cable of your downtube by hand to pull the derailleur arm across. I think that I may have mentioned this in an earlier post. Of course with the shifters it pulls at the right increment of the cable to the next gear. Do you access to another bike so that you can feel the tension on another derailleur spring ?

I do have an old mtb I'll have a look at that tomorrow

 

[roubaixtuesday]

Your derailleur looks well bashed and don’t you ever clean your wheels?

Your off topic offer to clean my wheels and "unwellbash" my perfectly operating derailleur is accepted.

Let me know your availability.

 

[Nigelnightmare]

JMTPW
My advice is to check the shifter for any stiffness, & check for foreign bodies like frayed cable jammed inside.
After all you have re aligned the rear derailleur, replaced the hanger, renewed the cables & checked the routing of them.
And from the sounds of it there is something wrong with the shifter because you say that it drops down when the cable is removed and it will go in if you push the rear derailleur with the cable connected.
So as long as the cable is free & easy to move when disconnected its not going to be that causing the problem.
Check the shifter operation by holding the cable under tension and working it through the gears so that you can feel how much the cable moves and how stiff/easy it is for each click/gear.
If it doesn't move as freely/easily in 1 or 2 of them then you have found the problem.

HTH

Also,
It looks like the 'B' stop screw needs to be adjusted to get the top jockey wheel closer to the cassette, it should be around 5-6mm away from the biggest cog and stay as close as possible to the rest, without touching, as you drop through the gears (from big to small).

 

[gazza81]

Thanks, i just tried this i can feel it pulling equal amounts of cable through when i take the cable out and hold it.

Ive also adjusted the B screw.

So its not the cable, in or out, its not the shifter or hanger alignment, chain or cassette
Does that only leave a faulty mech?

 

[DCBassman]

Doesn't prove the cable isn t frayed in the shifter, unless it's a new inner. If it is, I'll shut up now!
My next step would be to remove the rear mech and give it a thorough clean and lube, and if that doesn't work, try and find a substitute and see if that does.