Sram transmission chain not seating on 3rd gear

[pontoon]

Hey, I’m installing a Sram xx transmission on my 23 turbo levo.

Out of the box the shifting was ok except for 3rd gear, where it would go up and down between 3rd and 4th.

I used micro adjust to move the shifter further inboard (Micro adjust on 6) and it stays on all gears.

However, in gear 3, 3 or 4 times per rotation, I hear a clunking noise. I found it’s from the cassette on the 3rd cog. The chain is riding on top of the teeth somewhat. The chain won’t stay fully seated onto the teeth.

I am testing this in the bike stand. So it’s possible it’ll shift better under load.

Anyone experienced this? I tried repeating the transmission installation instructions, same result.

 

[Mikerb]

Hey, I’m installing a Sram xx transmission on my 23 turbo levo.

Out of the box the shifting was ok except for 3rd gear, where it would go up and down between 3rd and 4th.

I used micro adjust to move the shifter further inboard (Micro adjust on 6) and it stays on all gears.

However, in gear 3, 3 or 4 times per rotation, I hear a clunking noise. I found it’s from the cassette on the 3rd cog. The chain is riding on top of the teeth somewhat. The chain won’t stay fully seated onto the teeth.

I am testing this in the bike stand. So it’s possible it’ll shift better under load.

Anyone experienced this? I tried repeating the transmission installation instructions, same result.

View attachment 116195

B tension set correectly ( at SAG)?

 

[Ou812]

B tension set correectly ( at SAG)?

There’s no B tension or limit screws on the transmission, there’s no need for them since the distance between the cassette and derailleur is constant.

 

[Alexbn921]

It out of sync. Put some real pressure on the cranks and it will jump 1 tooth to sync the narrow wide. Or lift the chain up and move it 1 tooth front or rear.

 

[pontoon]

I did manage to fix the “issue”. I used micro adjust to go a little further from standard. I tried using more speed on the stand (needed pedals) and it improved. I went for a ride and came back and now I don’t see the issue on the stand any longer.

 

[Mikerb]

There’s no B tension or limit screws on the transmission, there’s no need for them since the distance between the cassette and derailleur is constant.

Ah!! Thats the problem then......progress he he!!

 

[Mikerb]

Ah!! Thats the problem then......progress he he!!

...seriously I have found even with ordinary gx axs that gear change can be perfect when riding but often a bit reluctant on one gear or another when on the stand. It may have something to do with the difference in chain tension when on the stand due to the rear triangle just hanging.

 

[blob]

Well, I'm also having a lot of problems with gear 3 and I can't get it to work properly.

When all other gears work fine, gear 3 will be very jerky and will constantly jump between gears. Gear 3 is only kinda happy with micro-adjust set to 1, but even then it starts skipping under heavy load on ascents. However, with micro-adjust set to 1 gear 11 stops working properly.

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[pontoon]

Well, I'm also having a lot of problems with gear 3 and I can't get it to work properly.

When all other gears work fine, gear 3 will be very jerky and will constantly jump between gears. Gear 3 is only kinda happy with micro-adjust set to 1, but even then it starts skipping under heavy load on ascents. However, with micro-adjust set to 1 gear 11 stops working properly.

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Have you taken it for a ride yet?

I ended up on micro adjust 4 with a 52mm chain line, gen3 levo, cascade long link with BB in low setting, 120 links, B setup position, size s3, 36t chainring, setup cog 21t. I found it shifts best on the stand if I spin out on gear 12 (using pedals) and then shift through the gears reasonably quickly (while there is still speed) to test each one out.

I also suspect the grease from the factory being slightly worn off is helping it shift better on the stand. The factory grease felt somewhat tacky to me.

In any case, micro adjust 4 and one ride seems to have improved things for me. That said, my bike kept it on the correct cog on the stand before I rode it as long as I didn’t push the micro adjust too far.

Check Bike calculator

Also double check the setup cog, setup key, chain length, removing chain slack when tightening, etc per manual

 

[blob]

Have you taken it for a ride yet?

I ended up on micro adjust 4 with a 52mm chain line, gen3 levo, cascade long link with BB in low setting, 120 links, B setup position, size s3, 36t chainring, setup cog 21t. I found it shifts best on the stand if I spin out on gear 12 (using pedals) and then shift through the gears reasonably quickly (while there is still speed) to test each one out.

I also suspect the grease from the factory being slightly worn off is helping it shift better on the stand. The factory grease felt somewhat tacky to me.

In any case, micro adjust 4 and one ride seems to have improved things for me. That said, my bike kept it on the correct cog on the stand before I rode it as long as I didn’t push the micro adjust too far.

View attachment 116737

Check Bike calculator

Also double check the setup cog, setup key, chain length, removing chain slack when tightening, etc per manual

Yeah, I’ve taken it on many rides, at least some 300 kilometers so far.

I also went through the entire setup process for a couple of times, triple checked everything, but gear 3 just refuses to cooperate…

 

[pontoon]

Yeah, I’ve taken it on many rides, at least some 300 kilometers so far.

I also went through the entire setup process for a couple of times, triple checked everything, but gear 3 just refuses to cooperate…

Sorry that’s too bad. I don’t know why that would be

Have you contacted SRAM? Their technical support is excellent

 

[Zimmerframe]

The T-type uses a narrow wide cassette (like most chainrings).

As @Alexbn921 says, the chain is installed on the cassette out of sync. You can clearly see this on @pontoon's pictures.

Presumably whilst riding and trying things, the chain has jumped to the correct teeth, or the teeth have worn so it's sitting tighter.

@blob if your's looks like that, just lift the chain away from the cassette and drop it 1 tooth over so the narrow chain links are on the thin teeth and the wide links are on the fat teeth.

 

[blob]

@blob if your's looks like that, just lift the chain away from the cassette and drop it 1 tooth over so the narrow chain links are on the thin teeth and the wide links are on the fat teeth.

The chain is seated properly. It doesn't fit if I try to move it by one link (because then narrow links get on top of wide teeth).

I think my 3rd cog might be defective... It's hard to get a good photo of this, but it looks to me that the offset between these two teeth is just too big. It seems slightly bigger compared to other gears and because of that the narrow link always climbs on top of the second tooth.

 

[blob]

Have you contacted SRAM? Their technical support is excellent

Yeah, I did a couple of days ago, but seems they are busy and the replies are slow-ish so haven't made any real progress yet.

 

[RAG]

Yeah, I did a couple of days ago, but seems they are busy and the replies are slow-ish so haven't made any real progress yet.

Possibly a long shot but have you upgraded the firmware on the derailleur?

 

[blob]

Possibly a long shot but have you upgraded the firmware on the derailleur?

Yes, everything up-to-date.

 

[RAG]

Yes, everything up-to-date.

View attachment 116784

I fitted XX myself this week and the only observation I would add from your video is that your cage looks ridiculously extended forward in gear 1.

Mine is running great but my derailleur doesn’t extend forward anything near like that in gear 1.

Are you certain you’ve got your chain sized correctly for chainring size, CS length, geo adjustment etc?

 

[blob]

Well, I cut the chain to 118 links as instructed by the calculator (Levo Gen 3, S4, high position, 36T chainring).

 

[RAG]

For comparison:

Gear 1:

Gear 12:

 

[RAG]

Well, I cut the chain to 118 links as instructed by the calculator (Levo Gen 3, S4, high position, 36T chainring).

View attachment 116785 View attachment 116786

Maybe it’s just my eyes on the p1ss

 

[pontoon]

Are you pulling the slack out of the chain when tightening? Are the lines aligned on the mounting point?

 

[RAG]

Are you pulling the slack out of the chain when tightening? Are the lines aligned on the mounting point?

…..And ensure the derailleur is in the setup mode position when the slack is being taken up while tightening.

 

[RAG]

I wonder if there’s an anomaly on the sizing calculator for your bikes.

If you use the sizing matrix instead of the calculator it shows you should be cutting your chain to 120 links:

 

[pontoon]

Just wanted to confirm after another ride, the shifting is flawless despite the “issue” I initially noticed on the stand

 

[Silver fox]

Possibly a long shot but have you upgraded the firmware on the derailleur?

It looks to me from your last photo, that the tooth on the right side of your red red ring is bent outward. Can you straighten it if that is the case?

 

[blob]

Are you pulling the slack out of the chain when tightening? Are the lines aligned on the mounting point?

Yes and yes.

…..And ensure the derailleur is in the setup mode position when the slack is being taken up while tightening.

And yes.

I wonder if there’s an anomaly on the sizing calculator for your bikes.

If you use the sizing matrix instead of the calculator it shows you should be cutting your chain to 120 links:

View attachment 116830

Well, this is interesting... I have a spare chain so I might try it with 120 links. But still, since I'm right on the edge between 118 and 120 links I would expect it to work fine with both.

It looks to me from your last photo, that the tooth on the right side of your red red ring is bent outward. Can you straighten it if that is the case?

I still think that might be the case since all other gears work perfectly, and gear 3 doesn't work at all. Just doesn't make sense for one gear to work so bad while all others are fine. But I'd probably make things much worse if I try to do that, especially without having another cassette for reference.

 

[RAG]

Yes and yes.

And yes.

Well, this is interesting... I have a spare chain so I might try it with 120 links. But still, since I'm right on the edge between 118 and 120 links I would expect it to work fine with both.


I still think that might be the case since all other gears work perfectly, and gear 3 doesn't work at all. Just doesn't make sense for one gear to work so bad while all others are fine. But I'd probably make things much worse if I try to do that, especially without having another cassette for reference.

Sounds like swapping out the chain is worth a punt, my vague logic is that the chain length on this system is critical as it also determines the ‘b gap’ that’s no longer adjustable, so while I agree a shorter or longer chain wouldn’t normally cause an issue with just one gear on a cassette, a stuffed b gap position might.

 

[Silver fox]

Yes and yes.

And yes.

Well, this is interesting... I have a spare chain so I might try it with 120 links. But still, since I'm right on the edge between 118 and 120 links I would expect it to work fine with both.


I still think that might be the case since all other gears work perfectly, and gear 3 doesn't work at all. Just doesn't make sense for one gear to work so bad while all others are fine. But I'd probably make things much worse if I try to do that, especially without having another cassette for reference.

You should be able to grab that tooth with a small pair of vice grips and move it straight visually without doing and damagr. Be gentle. They do move fairly easily.

 

[Tooks]

I fitted an XO Transmission to my Levo today, and funnily enough 3rd biggest ring was like a bag of spanners as well and the chain sat on the cog in my workstand exactly like yours.

I took it out for a test ride and ended up micro adjusting the derailleur 5 stops (so 1mm @ .2mm a click) and now it shifts perfectly and stays put on the ring and sits properly.

 

[Jun43]

just wanted to add to this and I had the same 3rd gear problem but fixed it after doing a ride with micro adjustment( 6 )