Trouble with rear gears

[gazza81]

I'm having trouble adjusting my rear gears, I've set the limit screws for the smallest cog and the biggest cog.
What seems to happen is with the chain in the smallest cog I change up one Gear to the next biggest cog if it doesn't change i tighen the cable via the cable retention screw.
Once it gets about 3 or 4 up the cassette I have to adjust the retention screw a little more but once I get to the last gear, the biggest cog it won't change into it?

Basically I've lost a gear either the highest gear or the lowest Gear I can't get them to change into all 10 gears.

I hope that make some sort of sense!

 

[MichaelW2]

How old and worn out is your rear derailleur?

 

[gazza81]

No idea I bought the bike last week is 2014 Marin argenta, I'll try and pop up a picture of it later as I wouldn't know a worn rear derailleur if I saw one!

 

[Slioch]

Need pics, but initial thoughts as to possible reasons include....

1. Rear mech has been bashed and is out of alignment.
2. Cables (inner & outer) need replacing. Cable could be frayed inside the shifter where you can't see it.
3. If you loosen the cable retention bolt and hold the loose cable with your fingers, do you get the required number of "clicks" on the shifter. i.e. if it's 10 speed do you get 10 clicks?

 

[Shearwater Missile]

Need pics, but initial thoughts as to possible reasons include....

1. Rear mech has been bashed and is out of alignment.
2. Cables (inner & outer) need replacing. Cable could be frayed inside the shifter where you can't see it.
3. If you loosen the cable retention bolt and hold the loose cable with your fingers, do you get the required number of "clicks" on the shifter. i.e. if it's 10 speed do you get 10 clicks?

I think there would be only 9 clicks on a 10 speed as you would already be on the extreme cogs in either direction.

 

[robgul]

My 2p
1 Is the chain worn (i.e. "stretched")?
2 Are you cross-chaining? - a lot of systems don't like big chainring to big sprocket and and vice versa

... and the other comments already made

Rob

 

[screenman]

Certainly a rear mech alignment problem, should always be the first place to start before doing anything else on the rear mech.

 

[Globalti]

No, start with the cable. If you haven't replaced the read cable outer in the last 6 months that's the likeliest problem. They get crudded up with rust and dirt.

 

[Racing roadkill]

Start the process again making sure any barrel adjusters are wound right in, before you start, then hold the mech open a bit ( pinch the joint ) and make sure the cable is taut when you clamp it down ( whilst pinching the mech joint open ).Then start the indexing process again. It’s more than likely the slack in the mech spring, isn’t being accounted for, pinching the mech open a bit takes this ‘slack’ out.

 

[Smokin Joe]

My 2p
1 Is the chain worn (i.e. "stretched")?


Rob

A worn chain won't prevent the gears from shifting.

 

[gazza81]

Start the process again making sure any barrel adjusters are wound right in, before you start, then hold the mech open a bit ( pinch the joint ) and make sure the cable is taut when you clamp it down ( whilst pinching the mech joint open ).Then start the indexing process again. It’s more than likely the slack in the mech spring, isn’t being accounted for, pinching the mech open a bit takes this ‘slack’ out.

Sorry what do you mean by pinching the mech joint open?
As in when ive taken the cable out of the retaining screw, push the derailleur away from the frame towards the wheel before clamping the cable?

 

[Racing roadkill]

Sorry what do you mean by pinching the mech joint open?
As in when ive taken the cable out of the retaining screw, push the derailleur away from the frame towards the wheel before clamping the cable?

With the cable through, in position and un clamped, pinch the joint in the mech, so that it opens up ( just a little bit, not all the way to the stop), hold that with one hand, tug the cable gently, with the other hand, then clamp the cable down, whilst keeping the pinch on the mech. It takes a bit of practice, but it solves the problem you mentioned.

 

[roubaixtuesday]

A worn chain won't prevent the gears from shifting.

I think it can make a bit of a difference, a worn chain is a bit slacker sideways, as well as "stretched" if you see what I mean?

 

[Smokin Joe]

I think it can make a bit of a difference, a worn chain is a bit slacker sideways, as well as "stretched" if you see what I mean?

I see what you're getting at, but it isn't the case. The chain will go where the derailleur takes it no matter how worn it is.

 

[I like Skol]

Second hand bike with wrong rear wheel/cassette fitted maybe? What model is it, the Sora gears? Could be 9spd gears and a 10 spd cassette which would explain the problem.