GX 12sp Shifting

[love2fly]

My Eagle GX 12 speed has always behaved impeccably and has only needed attention in the form of new shift cables and housing and maybe a tweak to the B screw once or twice.

Recently I've had a skipped gear on shifting down the cassette, around middle gear. I replaced the housing and cable and all is ok except the last 2 gears (second smallest and smallest) where on one cable tension it will skip straight to smallest or on the other it won't go beyond 2nd smallest. I checked my (XX1) chain and it's still perfect. B screw is as per Sram tool at 35% sag and I have played with B screw on either side of spec.

I was told it could be the hanger that's bent....admittedly my cassette is quite high mileage but I haven't had any slipping whatsoever.

Any well educated guesses or thoughts?

Thanks in advance.

[RobertWhitehead]

22 minutes ago, love2fly said:

My Eagle GX 12 speed has always behaved impeccably and has only needed attention in the form of new shift cables and housing and maybe a tweak to the B screw once or twice.

Recently I've had a skipped gear on shifting down the cassette, around middle gear. I replaced the housing and cable and all is ok except the last 2 gears (second smallest and smallest) where on one cable tension it will skip straight to smallest or on the other it won't go beyond 2nd smallest. I checked my (XX1) chain and it's still perfect. B screw is as per Sram tool at 35% sag and I have played with B screw on either side of spec.

I was told it could be the hanger that's bent....admittedly my cassette is quite high mileage but I haven't had any slipping whatsoever.

Any well educated guesses or thoughts?

Thanks in advance.

I have found it to be the hanger. You'll be able to get it sorted without fixing the hanger but it will take you longer to get it perfect. 

[love2fly]

What would be involved to sort it without getting the hanger straightened. I've basically reset and adjusted upper and lower limits, replaced cable and set B screw ...

[David Marshall]

If the hanger is bent it will have to be re aligned.  If that does not sort it start looking at the cassette.

[love2fly]

58 minutes ago, David Marshall said:

If the hanger is bent it will have to be re aligned.  If that does not sort it start looking at the cassette.

👍 Have a spare (used) cassette to try....

[RobertWhitehead]

19 hours ago, love2fly said:

What would be involved to sort it without getting the hanger straightened. I've basically reset and adjusted upper and lower limits, replaced cable and set B screw ...

You will have a few options if you don't want to straighten the hanger:

 

1) Make peace with the fact that you will have a gear or two that's going to be iffy. You'll be able to adjust this mid ride via the barrel adjuster on the shifter, but overall it's going to need some fiddling during the ride. This will become old quite quickly. 

 

2) Swop the GX for Shimano as they're more forgiving when it comes to out of shape hangers. 

 

1 hour ago, David Marshall said:

If the hanger is bent it will have to be re aligned.  If that does not sort it start looking at the cassette.

Do you have slipping under load i.e. The moment you put force it feels like the cassette gives way? This is an indication of a worn cassette. If the chain struggles to stay in one gear even with the absence of load then it's adjustment and or hanger. 

[love2fly]

1 hour ago, RobertWhitehead said:

You will have a few options if you don't want to straighten the hanger:

 

1) Make peace with the fact that you will have a gear or two that's going to be iffy. You'll be able to adjust this mid ride via the barrel adjuster on the shifter, but overall it's going to need some fiddling during the ride. This will become old quite quickly. 

 

2) Swop the GX for Shimano as they're more forgiving when it comes to out of shape hangers. 

 

Do you have slipping under load i.e. The moment you put force it feels like the cassette gives way? This is an indication of a worn cassette. If the chain struggles to stay in one gear even with the absence of load then it's adjustment and or hanger. 

No slipping whatsoever.

It started just as you described and it was usually one or two gears roughly mid cluster. Now it's buy-one-get-three....on the lower end of the cluster: One click down, nothing. Another click it goes down two, then the third click to go back up to the requested gear 😁. Planning on consulting my LBS re the hanger at least. I've always, always had the best success setting my gears on the stand and fine tuning on the road.

Yeah to Shimano but currently my arms are short and my pockets long ...

[RobertWhitehead]

14 minutes ago, love2fly said:

No slipping whatsoever.

It started just as you described and it was usually one or two gears roughly mid cluster. Now it's buy-one-get-three....on the lower end of the cluster: One click down, nothing. Another click it goes down two, then the third click to go back up to the requested gear 😁. Planning on consulting my LBS re the hanger at least. I've always, always had the best success setting my gears on the stand and fine tuning on the road.

Yeah to Shimano but currently my arms are short and my pockets long ...

I don't know everything but maybe this will help: 

1) Turn the barrel out multiple turns

2) Drop the gears to the bottom (heavy gear) 

3) Loosen the cable and watch the rear mech re-adjust itself with the 11T

4) Use a plier to pull the cable without putting too much strain on the mech

5) Fix the cable with the bolt

6) Start clicking to go upwards and once the gears start making a noise (that they no longer want to shift) reduce the tension on the cable with the barrel (shifter). 

You will notice that the barrel will need quite a lot of adjustment, you may run out before the gear will stop making a noise. If this happens start 1-6 over again but increase the barrel by a few turns. 

Good luck

Edited May 5 by RobertWhitehead
Skarramoesh

[love2fly]

23 minutes ago, RobertWhitehead said:

I don't know everything but maybe this will help: 

1) Turn the barrel out multiple turns

2) Drop the gears to the bottom (heavy gear) 

3) Loosen the cable and watch the rear mech re-adjust itself with the 11T

4) Use a plier to pull the cable without putting too much strain on the mech

5) Fix the cable with the bolt

6) Start clicking to go upwards and once the gears start making a noise (that they no longer want to shift) reduce the tension on the cable with the barrel (shifter). 

You will notice that the barrel will need quite a lot of adjustment, you may run out before the gear will stop making a noise. If this happens start 1-6 over again but increase the barrel by a few turns. 

Good luck

Thanks I'll try that. I normally do exactly that but start by screwing the barrel all the way IN and go from there. Need to wash today's ride and I'll have a look tomorrow.

🙂

[Michael S]

Top tip from Seths Bike Hacks. 

If you have shifting issues. Take off your derailleur, put it in a glass of water, if it sinks, the derailleur is bent and you should replace it or straighten it...

[ChrisF]

A hangher allignment tool is a once off cost.

 

In our sport these issues is part of the game.

 

Some bike shops still have the will and the skills to do this quickly .... but it really is one of the easier things to DIY with the correct tool.  

 

Parktool YouTube is an excellent tutor for this.

 

 

 

 

Yea yea ... we have all al some point eye-balled the hanger and bent it with a shifter .... alu work hardens, then snaps .... rather get the right tool for the job

[BaGearA]

On 5/4/2024 at 5:35 PM, love2fly said:

What would be involved to sort it without getting the hanger straightened. I've basically reset and adjusted upper and lower limits, replaced cable and set B screw ...

You might be able to get it okay for a couple of gears but a bent hanger equals crap shifting end of story.

 

Your derailleur and cassette are supposed to be on the same plane ( up and down) now with the hanger bent the derailleur is running slightly off that plane while the cassette is still spinning straight.

[MORNE]

5 hours ago, love2fly said:

No slipping whatsoever.

It started just as you described and it was usually one or two gears roughly mid cluster. Now it's buy-one-get-three....on the lower end of the cluster: One click down, nothing. Another click it goes down two, then the third click to go back up to the requested gear 😁. Planning on consulting my LBS re the hanger at least. I've always, always had the best success setting my gears on the stand and fine tuning on the road.

Yeah to Shimano but currently my arms are short and my pockets long ...

Had this exact issue on AXS and a GX lunar cassette that was used, but i wouldn't say done, maybe 2500km at most. Around mid cassette it was always faffing about. Exactly as you describe, had to drop two or three and go back up one to make it go where i wanted in a reasonable amount of time.

AXS allows you to micro adjust gears and while that did help, it would be 3-4rides and it would just do it again. I had a new hanger in a box for that bike too and it didn't change it either. 

Anyway, i sold that AXS as i did not get on with the TV button clicker in the end. XT solved that issue on that specific bike for me. As mentioned, i also think the shimano stuff has a wider sweetspot when it comes setup. Thats why they tend to be set and forget. Minor variances dont affect them. My GX was so sensitive to L/H/B adjustments. Thats why you get a measuring tool with the thing and need a friend to get the thing set at sag lol. Maybe a slightly worn cassette contributed in the end…but i never got it as smooth as the XT setup ended up being. 

Also, make sure your cassette is properly torqued down. If it is slightly loose you could have slight variances in where the gears run vs where they are supposed to run. Tiny sure, but could be and its a free check. 

Other than that, if you are convinced your hanger has not taken a knock since it all used to work…maybe your cassette might be nearing its end in those specific cogs🤷🏻‍♂️

 

[love2fly]

16 minutes ago, MORNE said:

Had this exact issue on AXS and a GX lunar cassette that was used, but i wouldn't say done, maybe 2500km at most. Around mid cassette it was always faffing about. Exactly as you describe, had to drop two or three and go back up one to make it go where i wanted in a reasonable amount of time.

AXS allows you to micro adjust gears and while that did help, it would be 3-4rides and it would just do it again. I had a new hanger in a box for that bike too and it didn't change it either. 

Anyway, i sold that AXS as i did not get on with the TV button clicker in the end. XT solved that issue on that specific bike for me. As mentioned, i also think the shimano stuff has a wider sweetspot when it comes setup. Thats why they tend to be set and forget. Minor variances dont affect them. My GX was so sensitive to L/H/B adjustments. Thats why you get a measuring tool with the thing and need a friend to get the thing set at sag lol. Maybe a slightly worn cassette contributed in the end…but i never got it as smooth as the XT setup ended up being. 

Also, make sure your cassette is properly torqued down. If it is slightly loose you could have slight variances in where the gears run vs where they are supposed to run. Tiny sure, but could be and its a free check. 

Other than that, if you are convinced your hanger has not taken a knock since it all used to work…maybe your cassette might be nearing its end in those specific cogs🤷🏻‍♂️

 

I've gotten so good at setting B I let the air out the shock on the stand and pull the triangle until it's between 30 and 40% 😁.

If I had the budget I'd go Shimano....going to get hanger checked at LBS but might just do a freehub service as it's time and try my spare but we'll used cassette.

[David Marshall]

I don't understand why you would avoid properly checking the alignment of the hanger.  If it is not bent at least you have eliminated it as an issue and can look elsewhere for the problem. 

Poor shifting can be due to a number of causes. You have to eliminate them one by one.

Find someone with a tool and get it done.  In my workshop I charge R120 to for the job.  

[dave303e]

On 5/4/2024 at 5:35 PM, love2fly said:

What would be involved to sort it without getting the hanger straightened. I've basically reset and adjusted upper and lower limits, replaced cable and set B screw ...

my 2c. Buy a new hanger right away. Remember it is a sacrificial part meant to break so your derailleur doesn't break.
Put the new one on the bike and then get this one straightened and then put it in your saddle bag as a spare. Every bike should have a spare hanger on it at all times. Nothing worse than breaking a hanger or bending one badly and ruining a ride for something that weighs 20 grams and takes 2 mins to change.