Gear change rub!

[Mal69]

I have been trying to fix this and ran into problems.

I attach a pic below but i have found the L screw was not moving the cage until i loosened the cable, it was set very tight and i have ended up having it come off whatever it was tightened to, i am not sure how to get it back on, or where it attaches to tighten it back on.

The other issue is no matter how hard i try, there are gears where the chain rubs the cage, i mean a lot of unusable gears, seems to me only putting the gearing onto the middle ring solves 95% of this chain rub.

Can anyone help me, i wish i was near a place which would fix this for me, does anyone know of a place in the Scottish Borders?

 

[Mal69]

Now i have accidentally took the back screw off the bit above after seeing where the cable goes to tighten it but finding it hard to put in.

How do,i manage to get that part on?

 

[Deleted member 4366]

I would love to be able to help you, but I'm too thick to understand what's come off.

To adjust the derailleur;
Loosen the cable clamp;
Adjust the L screw until the derailleur lines up with the small ring. turn the pedals to make sure that there's no rubbing when on the lower gears;
Turn the cable adjuster fully in;
Pull the cable until all the slack is taken up, then tighten the clamp. Check that the chain still doesn't rub when in the lower gears;
Shift onto the middle ring. Check that the chain doesn't rub in the middle gears. Make small adjustments of the cable adjuster to get it just right;
Shift onto the large ring. Adjust the H screw to stop the derailleur over-running. Make sure that it allows the derailleur to go far enough;
Check again in each shift position and make small adjustments of the cable adjuster to get it right.

 

[Gadfly]

Do you know the model of derrailleur you have? Fittings do vary a bit. As far as chain rubbing is concerned, ensure the derailleur cage is parallel with the chain wheel.

 

[JPGiant]

Those two square components are basically a clamp to hold the gear change wire.
They usually only go on the Rear Derailleur one way round by locating a lug into a flat section of the assembly whilst aligning with the other part where the cable slots in.
This is a good video of how to set the RD...
https://www.artscyclery.com/learningcenter/shimanorearderailleurs.html

 

[Mal69]

I spent half the day on this, watched youtube videos on how to do it, i hold my hands up, i am useless at mechanics, this is probably easy but i am finding it too much, i fixed the disc brakes from rubbing, was able to index the gears but i just cannot get this right.

I have phoned a shop in the next town, probably looking at £25 for thirty minutes work, some time late next week as they are busy.

I dont think i put those two parts back in right, its very hard to do while keeping it all attached to the bike and i see no way to get it off the bike without removing other things.

 

[JPGiant]

I have a feeling I need to apologise, is it the Front Derailleur at fault?

 

[Mal69]

I have a feeling I need to apologise, is it the Front Derailleur at fault?

I believe so, bit where the pedals are and chain rub when gears change, i have messed it up by trying to fix it due to those bits coming loose.

 

[D C]

The other issue is no matter how hard i try, there are gears where the chain rubs the cage, i mean a lot of unusable gears, seems to me only putting the gearing onto the middle ring solves 95% of this chain rub.

This is usually quite normal, with the chain on the centre chain ring all the rear cogs should be usable, the large chain ring should get the smaller rear cogs for about two thirds of the way across but shouldn't be used on the larger rear cogs and the small chain ring should get the larger rear cogs but shouldn't be used on the smaller rear cogs.
A crossed chain isn't good as everything will wear out quickly and a good chance of the chain jumping across or even coming off.
it sounds like some slight adjustment may be needed to get the 95% to 100%.
Dave.