Rear derailleur shifting weirdly ?

R.dufy454773

I’ve recently noticed that when shifting up to easier / larger Cogs at the rear cassette when I shift up one gear, it shifts up to gears and then drops down one gear to the gear I want . (It’s a fairly new bike so chain/ cables couldn’t be worn )


Anyone know how to fix this ? Thanks

rollingscone

R.dufy454773 wrote: »

I’ve recently noticed that when shifting up to easier / larger Cogs at the rear cassette when I shift up one gear, it shifts up to gears and then drops down one gear to the gear I want . (It’s a fairly new bike so chain/ cables couldn’t be worn )


Anyone know how to fix this ? Thanks

Have you taken the wheel off recently?

If not, is the casette loose?

R.dufy454773

rollingscone wrote: »

Have you taken the wheel off recently?

If not, is the casette loose?

Hi, yes I have taken the wheel off recent and I think it was just skipping gears before but not sure because I didn’t try to fix it . And i don’t think the cassette is loose

07Lapierre

R.dufy454773 wrote: »

I’ve recently noticed that when shifting up to easier / larger Cogs at the rear cassette when I shift up one gear, it shifts up to gears and then drops down one gear to the gear I want . (It’s a fairly new bike so chain/ cables couldn’t be worn )


Anyone know how to fix this ? Thanks

They could be. How old is the bike exactly?

mp31

Sounds like the rear derailleur may need adjustment via the barrel adjuster.

Note that a small movement on the shifter will move the chain across one sprocket, a larger movement on the shifter will move the chain across two sprockets

R.dufy454773

07Lapierre wrote: »

They could be. How old is the bike exactly?

I bought it in November and have only done about 500-600km snd they don’t feel/ look worn

R.dufy454773

mp31 wrote: »

Sounds like the rear derailleur may need adjustment via the barrel adjuster.

Note that a small movement on the shifter will move the chain across one sprocket, a larger movement on the shifter will move the chain across two sprockets

Yeah I know but I only move it slightly and it moves up two then goes back one to where I want it

R.dufy454773

mp31 wrote: »

Sounds like the rear derailleur may need adjustment via the barrel adjuster.

Note that a small movement on the shifter will move the chain across one sprocket, a larger movement on the shifter will move the chain across two sprockets

Yeah I know but I only move it slightly and it moves up two then goes back one to where I want it

CrowdedHouse

Did the bike fall over or get a bump on the drive side? my one behaved kinda like that when I bent the hanger.

The Ging and I

Your drop out might be out of alignment and this is the biggest cause of rear mech problems. Bring it to a shop which has the tool to check this.

R.dufy454773

I don't think it's bent? The jockey wheels are directly under the chain ?🤔

What Username Guidelines

Could be new cables stretching and the rear derailleur just needs some adjusting

07Lapierre

R.dufy454773 wrote: »

I bought it in November and have only done about 500-600km snd they don’t feel/ look worn

500-600k? ...yep cables have stretched.

R.dufy454773

07Lapierre wrote: »

500-600k? ...yep cables have stretched.

Yeah I know they stretch but they don't need to be replaced do they ?


Btw* I just checked and I have only done about 396km but I still think they have stretched but not needing to be replaced

07Lapierre

R.dufy454773 wrote: »

Yeah I know they stretch but they don't need to be replaced do they ?

No, but the rear derailleur cable may need to be tightened.


https://youtu.be/Bbk5RcH0bbQ

What Username Guidelines

R.dufy454773 wrote: »

Yeah I know they stretch but they don't need to be replaced do they ?


Btw* I just checked and I have only done about 396km but I still think they have stretched but not needing to be replaced

No, no need to replace, they generally just stretch from usage when new and once adjusted it should be fine.

R.dufy454773

What Username Guidelines wrote: »

No, no need to replace, they generally just stretch from usage when new and once adjusted it should be fine.

Yeah that's what I thought

martyc5674

A stretched cable on your rear derailleur would manifest as a reluctance to go into the lower gears(larger sprockets)... your experiencing the opposite where it is actually pushing the derailleur towards the lower gears. Something else is causing this.
Marty.

R.dufy454773

martyc5674 wrote: »

A stretched cable on your rear derailleur would manifest as a reluctance to go into the lower gears(larger sprockets)... your experiencing the opposite where it is actually pushing the derailleur towards the lower gears. Something else is causing this.
Marty.

Hi Marty,


When I try to shift in to a lower/easier gear the derailur shifts up 2 cogs instead of one , so it is reluctant to go into lower gears. I think you think the opposite but correct me if I’m wrong .

I’ll look at tightening the cable in the morning

martyc5674

R.dufy454773 wrote: »

Hi Marty,


When I try to shift in to a lower/easier gear the derailur shifts up 2 cogs instead of one , so it is reluctant to go into lower gears. I think you think the opposite but correct me if I’m wrong .

I’ll look at tightening the cable in the morning

No I reckon I understood you correctly.
If it’s shifting 2 sprockets instead of one when down shifting (albeit momentarily and returning to actually only shift 1 position)... then a stretched cable is not the issue.
A stretched cable would manifest as a reluctance to go down gears.. yours is almost going down 2.
Marty.

R.dufy454773

martyc5674 wrote: »

No I reckon I understood you correctly.
If it’s shifting 2 sprockets instead of one when down shifting (albeit momentarily and returning to actually only shift 1 position)... then a stretched cable is not the issue.
A stretched cable would manifest as a reluctance to go down gears.. yours is almost going down 2.
Marty.

Yes that’s it but it’s when I’m shifting up gears in to bigger tooth cogs I’d thats what you mean?

martyc5674

R.dufy454773 wrote: »

Yes that’s it but it’s when I’m shifting up gears in to bigger tooth cogs I’d thats what you mean?

Yeah that’s what I mean... the bigger gears at the back are the lower gears. (Smallest being highest)

Just to be clear... the quote above ”shifting up gears to bigger cogs” is incorrect.
It should be shifting down gears to bigger cogs.... bigger = lower.

R.dufy454773

martyc5674 wrote: »

Yeah that’s what I mean... the bigger gears at the back are the lower gears. (Smallest being highest)

Just to be clear... the quote above ”shifting up gears to bigger cogs” is incorrect.
It should be shifting down gears to bigger cogs.... bigger = lower.

Yes exactly thanks for saving me doing that , do you know anything I could try to fix it ?

martyc5674

You could try turning the barrel adjuster clockwise a quarter turn at a time to take some of the tension out of the cable.


Before you do that though make sure your back wheel is sitting home in the dropout.

Loosen skewer(pull lever back)... push down on saddle keeping s little pressure and retighten skewer.

As others have said it’s normal for cables to stretch but yours seems to have somehow shrunk so I reckon something else might have happened.
Marty.

R.dufy454773

martyc5674 wrote: »

You could try turning the barrel adjuster clockwise a quarter turn at a time to take some of the tension out of the cable.


Before you do that though make sure your back wheel is sitting home in the dropout.

Loosen skewer(pull lever back)... push down on saddle keeping s little pressure and retighten skewer.

As others have said it’s normal for cables to stretch but yours seems to have somehow shrunk so I reckon something else might have happened.
Marty.

I was messing about with the barrel adjuster for some other problem a few months ago whichu for get which it was but anyway I went to turn the barrel adjuster and it was really tight and super difficult to move

Then i said I’d try tighten the rear derailleur cable and I unscrewed the bolt out all the way by accident and then during this the gears went from the third hardest gear straight down to the smallest / hardest cog and then the derailleur cable popped out .

So I went to put it back in but I couldn’t pull it as tight as it was before . I then tried shifting and it makes a horrible clicking sound and it takes two clicks to go up 1 cog and it won’t go up any more

So now basically I’m stuck with only 2 gears that makes a clicking sound

I just couldn’t pull the cable as tight as it was before

07Lapierre

R.dufy454773 wrote: »

I was messing about with the barrel adjuster for some other problem a few months ago whichu for get which it was but anyway I went to turn the barrel adjuster and it was really tight and super difficult to move

Then i said I’d try tighten the rear derailleur cable and I unscrewed the bolt out all the way by accident and then during this the gears went from the third hardest gear straight down to the smallest / hardest cog and then the derailleur cable popped out .

So I went to put it back in but I couldn’t pull it as tight as it was before . I then tried shifting and it makes a horrible clicking sound and it takes two clicks to go up 1 cog and it won’t go up any more

So now basically I’m stuck with only 2 gears that makes a clicking sound

I just couldn’t pull the cable as tight as it was before

Remove the cable again. Then unscrew the barrel adjuster and remove it completely. Clean it with WD40... clean it with a cloth, clean the treads on the rear derailleur as well. Then put the barrel adjuster back but only thread it 1/2 way into the derailleur. Recommect the cable and then use the barrel adjuster to adjust the cable tension (that’s what it’s for)

R.dufy454773

07Lapierre wrote: »

Remove the cable again. Then unscrew the barrel adjuster and remove it completely. Clean it with WD40... clean it with a cloth, clean the treads on the rear derailleur as well. Then put the barrel adjuster back but only thread it 1/2 way into the derailleur. Recommect the cable and then use the barrel adjuster to adjust the cable tension (that’s what it’s for)

Remove just the plastic housing or the entire thing of the barrel adjuster thanks

07Lapierre

R.dufy454773 wrote: »

Remove just the plastic housing or the entire thing of the barrel adjuster thanks

the whole thing.

should look like this:

https://images-na.ssl-images-amazon.com/images/I/51G9hoT7X0L._SL1081_.jpg

R.dufy454773

07Lapierre wrote: »

the whole thing.

should look like this:

https://images-na.ssl-images-amazon.com/images/I/51G9hoT7X0L._SL1081_.jpg

Yes it’s like that thabks a lot



Edit : I am turning it away from the bike but the outer plastic housing won’t stray over the barrel adjuster it just springs out

07Lapierre

R.dufy454773 wrote: »

Yes it’s like that thabks alot

Watch this:

https://www.youtube.com/watch?v=Bbk5RcH0bbQ

R.dufy454773

07Lapierre wrote: »

Watch this:

https://www.youtube.com/watch?v=Bbk5RcH0bbQ[/quote

I think I’ve got the barrel adjuster sorted but the cable is still not as tight as before so that’s normal ?

R.dufy454773

Now I think I’ve got the barrel adjuster sorted ( the plastic housing is only covering half of the barrel adjuster) and the cable connected when I’m in the smallest ring and try to shift up the shifter moves but there is no tension it is really light and NOTHING. Happens at all until I get to the second last gear and then it changers


* at first it was in third gear and then changed to the lowest gear when i very first removed the cable

martyc5674

1. Click your shifter repeatedly towards the smallest cog.
2. Slacken the cable grip.
3. Screw the barrel adjuster all the way in.. then turn it back maybe a turn or 2.
4. If you have a barrel adjuster on your frame do the same.
5. Pull some tension on the end of the cable with a small pliers whilst tightening up the cable grip.
6. Shift up and down whilst spinning the cranks, you’ll likely find you need to tension cable with barrel adjuster a few turns.

That should get you into a good position.

R.dufy454773

martyc5674 wrote: »

1. Click your shifter repeatedly towards the smallest cog.
2. Slacken the cable grip.
3. Screw the barrel adjuster all the way in.. then turn it back maybe a turn or 2.
4. If you have a barrel adjuster on your frame do the same.
5. Pull some tension on the end of the cable with a small pliers whilst tightening up the cable grip.
6. Shift up and down whilst spinning the cranks, you’ll likely find you need to tension cable with barrel adjuster a few turns.

That should get you into a good position.

When I screw the barrel all the way , do I screw towards the bike ? And what exactly do you mean by cable grip , I thought screwing the barrel adjuster would slack off the cable? Thanks

martyc5674

R.dufy454773 wrote: »

When I screw the barrel all the way , do I screw towards the bike ? And what exactly do you mean by cable grip , I thought screwing the barrel adjuster would slack off the cable? Thanks

Yes screw it clockeise so that it shortens/threads into frame/derailleur.

Cable grip is the little guy that grips the cable on the derailleur.

R.dufy454773

I got messing around with the barrel adjuster and now it shifts smoothly however when I'm in my smallest cog, and I go to shift up one then nothing happens at all. I pressvit again and then it goes up but when I get to the second highest gear the shifter won't let me Shift up any more ( because the shifter "thinks" I'm already in the highest gear.

Any help would be much appreciated and thanks for all the responses so far

martyc5674

Yeah your out a full gear...
wind the barrel adjuster out until it skips up to the next gear and fine tune as per video.

If you can’t get it using the barrel start again... slackening the cable off the grip when in highest gear etc as per above.

R.dufy454773

martyc5674 wrote: »

Yeah your out a full gear...
wind the barrel adjuster out until it skips up to the next gear and fine tune as per video.

If you can’t get it using the barrel start again... slackening the cable off the grip when in highest gear etc as per above.

I’ve got the gears shifting pretty smoothly now but I’m out 3 gears I think or maybe 2.


When I try to unscrew the barely adjuster all the way in like u said , the housing falls off the barely adjuster so I have to pull the cable to keep the barrel adjuster on to turn it . Is that what I’m supposed to be doing

And even when I’m doing that I was unscrewing for about 7 mins and it kept going and didn’t really start to stop/ I couldn’t feel it being screwed in the whole way ??

martyc5674

The barrel adjuster is for fine tuning.
If your out by a gear or 2 you have to start again.

Some barrel adjusters have a clutch built into them to prevent you accidentally adjusting your gears by rubbing off the adjuster... I’m guessing that’s why your having some issue screwing it into the derailleur... if so you need to pull the thumb wheel towards you to engage it with the threaded section and then turn. (The exact opposite of a child safety lock in a bottle of calpol... you pull instead of push)


So start again...
Small ring... go to highest gear/smallest cog on the back...slacken cable grip.
Screw in barrel adjusters most of the way, tighten grip whilst pulling a little tension on the cable so there’s no slack between it and shifter.

Then try indexing it using the barrel adjusters.

R.dufy454773

If your saying undo the cable at derailleur, screw the barrel adjuster most of the way clockwise no then pull tight again at cable grip and start to use the barbell adjuster to fine tune the gears , then unfortunately,

I have just tried that and the gears are a bit out, I will try again

(I'm guessing I turn the adjuster anti clockwise when I'm fine tuning , correct?

Thanks

martyc5674

Yes initially you’ll be turning it anti clockwise to tension the cable...obviously if you over do it you’ll need to go back.

Make sure your shifter is clicked all the way down so that it’s expecting to be on the smallest cog/highest gear.(and that’s obviously where your derailleur should be..then tension the cable from its very tip and nip up the cable grip. Then go indexing.

I can’t say a whole lot more than that on the subject. YouTube surely has heaps of vids.

Look at this from about 3:20
https://youtu.be/-7ea5tpiM7I

He nips up the cable a few cogs up but that’s more likely to see you out a cog or two, I’ve always done it on smallest cog and not had a problem getting the tension in the cable but it is probably the trickiest bit.

magicbastarder

in all sincerity - don't rely on people online trying to explain in text how to adjust your rear derailleur - it's better explained in several of the videos linked - and if you're still having trouble, just bring the bike to a bike shop and pay the ten or fifteen quid to have it done professionally.

Type 17

If you don't find the GCN video easy to follow, try Park Tool's one instead - https://www.youtube.com/watch?v=UkZxPIZ1ngY