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SRAM Road AXS poor ...
 

SRAM Road AXS poor shifting…

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I’ve got a brand new road AXS system installed and I cannot adjust out poor shifting from 11-10-9 which are 1 tooth increments. It’s worst going 11-10 and it’s not every shift but 6 out of 10.

Basically it stays in the higher gear too long clicking as it does not catch the shift ramp fully and then does eventually go in. Once it gets past 9 it shifts instantly and perfectly all the way up the cassette and it’s also fine all the way down.

Things I’ve tried…

Hanger alignment checked with alignment gauge.
Full installation setup from scratch following the SRAM procedure and b gap alignment using the SRAM tool. High/Low limit adjustment etc all perfect.

Chain length correct. Brand new chain so zero wear.

Removed and reseated the cassette.

I’ve tried adjusting it out using the micro adjust also and while this improved it a bit it gets to the point that it’s rasping when I go too far and with no further improvement in shifting .

Anyone else had a similar issue or got any bright ideas ? Faulty derailleur? Faulty cassette?

 
Posted : 12/01/2025 9:19 pm
Daffy reacted
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How's the chainline, would that affect things - although you'd think that would give you a 9t problem.

 
Posted : 12/01/2025 9:37 pm
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Yeah the only thing I can think of that you haven't checked is the spacer between the BB and the crank. From memory there should be a 3mm on the right side, but it's worth checking the SRAM install guide for your flavour of BB/chainset as I think they do vary.

 
Posted : 12/01/2025 10:24 pm
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You say 9-10-11, so is this an e13 cassette?

If so, this means an XD freehub….now, do you have an XD or an XDR freehub?  As whilst the cassette will fit on both, they’re not the same.  The XDR freehub is 1.85mm longer which could be what’s pushing your chain line out.  Maybe?

 
Posted : 13/01/2025 5:12 am
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I haven't checked the spacer but it's a brand new bike with DUB BSA 68 and should have a 3mm drive side outer only according to the SRAM chart - can I tell if the spacer is there without removing the crank..? There is no play in the crank either.

It is a 2x12 with a 10-36 cassette (so not e13) and it shifts fine from the 12th gear (10 tooth) cog to the 11th gear (11 tooth) cog - it's just from 11 to 10 where its very poor.

Its the same when in either front chainring which is why I sort of ruled out chain line but apart from a dodgy cassette or derailleur that's about all it could be I suppose. Would poor chain line do the same in both chain rings?

 
Posted : 13/01/2025 5:48 am
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Could the mech hanger have been damaged in transit and be slightly out? It might be worth getting hold of an alignment tool or taking it to an LBS to get it checked.

 
Posted : 13/01/2025 6:19 am
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I’ve checked the hanger alignment with an alignment tool - it’s perfectly straight.

Just removed the crank arm and checked for the correct spacer too and it’s 3mm as per the SRAM chart.

 
Posted : 13/01/2025 6:45 am
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Is there a damaged tooth on the cassette or is there an abnormal space between the 10/11t?  Is the mech getting very close to the sprockets during this step of the transmission and a slight tweak to the b-screw tension or chain tension would solve it?

There needs to be a decent amount of tension (combination of chain length and tension) to get these to shift.  A shorter chain means you can relax the b-screw tension which brings the derailleur top pully forward, but not closer to the sprockets which gives better wrap around - this might allow the chain to catch the ramp quicker or pull it closer to the ramp.

 
Posted : 13/01/2025 7:19 am

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Something weird going on with the cassette spacers maybe? If one was completely missing it'd be fairly obvious, but maybe a too thick or too thin one.

If it's a brand new bike, isn't it the vendors issue?

 
Posted : 13/01/2025 7:19 am
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I’ve tried tweaking the b screw in both directions but it makes no noticeable difference.

The cassette is a SRAM one piece cassette so no issues with incorrect spacing.

Anyway, I’ve taken it back to LBS this morning for them to look at… they did say that there is a bed in period on these new SRAM cassettes and that they wear in rather than wear out so that maybe it - I’m happy if that’s the case but they’re going to triple check everything is as it should be and try another cassette just in case ….

 
Posted : 13/01/2025 11:45 am
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they did say that there is a bed in period on these new SRAM cassettes

mine have all been perfect out of the box...

I'd be taking that as a bit of a fob off TBH.

Good they are going to check it all over, is is a new bike supplied by them, or new bits on an older bike you already had ?

 
Posted : 13/01/2025 11:49 am
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I had this exact issue with a SRAM AXS mullet setup (X1/GX i think), perfectly aligned hanger, new cassette, spacers all correct, chainline etc. I determined that it was a loose bushing on the main bolt that attaches the mech to the hanger. Its poorly designed and comes wobbly from the factory, you can feel how much play there is in your hand and it's too much for the tight tolerances of 12 speed. Take the chain off and wobble the mech while its still attached and you can see how much movement there is.

I think the higher level AXS mechs have a better bushing installed which eliminates this, and there are retrofit kits available.

 
Posted : 13/01/2025 3:48 pm
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+1 the bushing on the main bolt that attaches it to the hanger.

They can wear more than they 'should' ... but the OP says his is a new setup, so wear can't be the problem.

It should shift properly when new, of course it should.

New sticky chains can make shifting sluggish. Give it a clean with WD40.

If the chainline/spacing is correct, and the AXS setup is new, then I'd be looking at a misaligned frame.

 
Posted : 13/01/2025 4:20 pm
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It’s a brand new Specialized Aethos with SRAM Red components and a waxed drivetrain. I’ve left it with them. I wasn’t particularly happy with the bed in excuse either but that was from a junior tech. I know my GX AXS with an X0 cassette has shifted perfectly from new and has got better. I showed the workshop manager and he said he’d get to the bottom of it so we’ll see….

 
Posted : 13/01/2025 5:13 pm
submarined reacted
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I've found chain length to be critical to reliable shifting on Sram installations. Sram's instructions leave the chain too long ime. Would it be possible to remove two links? I shift to big chainring / Big sprocket and then see how many links I can "pinch" on the chainring.

Sram used to make some road cassettes with a black coating. I always found those noisy until the coating had worn off. Otherwise, "newness" being the problem is rubbish!

Ace bike BTW.

 
Posted : 13/01/2025 10:51 pm
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Funnily enough I did take two links out as it was longer than the SRAM “overlap +1 inner and 1 outer”. I did wonder if this had made it too short actually but not if you think shorter is better!

I forgot to say also that it misses the occasional shift, from both levers. I mentioned this to the junior tech and he just said “known issue, look out for software updates “ . I wasn’t happy with this either on what is a £3.5k groupset and then forgot to mention to the workshop manager so I’ll ring him tomorrow. It may need a new derailleur…

Ace bike BTW.

Thanks, it’s lovely. Or it will be if they sort it out and the weather improves so I can take it out properly!

 
Posted : 14/01/2025 2:43 am

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Have you bedded in the waxed chain? My shifting was typically out for a few km after a fresh waxing (hot waxing) then settled down.

I wasted a good bit of time readjusting derailleurs then having to adjust them back again mid-ride 🙄

 
Posted : 14/01/2025 9:27 am
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I had a nightmare with mine, turned out that when i'd changed the cassette the spacer had been stuck to the back of the old one.  I was running an XD cassette on an XDR hub and although when tightened up it all looked and felt OK the shifting was dog poo.

 
Posted : 14/01/2025 9:48 am
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Have you bedded in the waxed chain?

Yeah I’ve done 60km on it. Plus probably the same again in the stand troubleshooting it!!!

 
Posted : 14/01/2025 9:49 am
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I emailed SRAM Rider Care and they have said they have not heard of any particular issues with the E1 groupset in regards to shifting performance and reliability. They’ve suggested corrupted firmware could be the cause and detailed how to force a firmware reload. Obviously bike is in the shop so hopefully they’ll do that without prompting but I’ll check…

 
Posted : 15/01/2025 5:13 am
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So, LBS rang me and said they’ve fixed it by applying some lube to the chain. This suggests to me that the issue is just masked by slipperiness now but I’m prepared to be convinced otherwise if someone wants to support their explanation…

The chain was freshly waxed and had done 60km, plus a fair bit of spinning up and down the cassette while I was troubleshooting. It’s a brand new chain obviously so has only had one application of wax but is this enough to cause poor shifting in a few gears…? Surely it would be very noisy and poor in all gears if lubrication was an issue…

 
Posted : 15/01/2025 6:59 pm
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Mapdec Cycle Works (high end mechanic place up in Kendal) have a new video about sorting out SRAM shifting issues. This was on a new Scott Foil (skip to 2:45 in the video to get past the "talking about the bike" to actually fixing the shifting). They go through it in quite some detail to solve the issues.

https://youtu.be/xqjmVzswmxI?si=WdRdFmJcaNp0yQ1o

It’s a brand new chain obviously so has only had one application of wax but is this enough to cause poor shifting in a few gears…? Surely it would be very noisy and poor in all gears if lubrication was an issue…

Waxing can make the chain quite stiff and reluctant to go around tight bends (like a SRAM 10T cog) so it wouldn't be entirely surprising. That said, 60km should have loosened it all up but who knows... Sometimes, they're just sensitive to adjustment.

 
Posted : 15/01/2025 8:00 pm
oceanskipper reacted
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Useful video - thanks!

I followed the SRAM installation instructions to the letter (quite a few times so I’m pretty familiar with them now!) and I also followed the subsequent fine tuning (the front mech shifts absolutely perfectly now I’ve tweaked it as it was initially dropping off the outside occasionally). I guess I’ll see when it comes back from the shop. I’ve got some Silca wax with an Endurance Chip to try instead of the MSW that I’m currently using also so once I’ve cleaned off whatever they have contaminated my wax with I’ll try that and see…. I’m also going to reload the firmware.

 
Posted : 15/01/2025 8:41 pm
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For the interests of comparison you should give it some riding with whatever lube the shop put on the chain before cleaning it off and relubing with a wax of your choice. As daft as it sounds at gives you a variable to compare with.

 
Posted : 16/01/2025 7:06 am

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Good idea - I’ll do that. I emailed another SRAM dealer not too far away and asked if they would give a second opinion too. The pro mechanic in this custom build workshop has a YouTube channel and seems to know what he’s talking about…

I just don’t expect it to need additional lubricant after only 60km in the dry on a freshly waxed chain. My Eagle AXS cassette does not shift anywhere near as poorly even when it gets a bit noisier indicating a re-wax is due. Its “bedded in” a bit more I suppose though if that’s a thing,  so there’s a chance this will do the same on that basis….

 
Posted : 16/01/2025 7:31 am
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Response from Backyard Bike Shop…

We are incredibly busy with builds at the minute so won't have time to have a look at this for you. We wouldn't recommend using chain wax so maybe try oil to see if this solves the problem.

That’s me told! It’s back from the shop and still not great, I would go so far as to say no better. Running out of options other than to just put up with it which is a bit of a poor outcome on what is a top of the range groupset.

 
Posted : 16/01/2025 7:06 pm
 5lab
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Any chance you could try a different chain on it? It could be the wax has clogged up the joints so they're not flexy enough?

 
Posted : 16/01/2025 7:23 pm
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I could try a different chain as I have a brand new one still with factory grease on it ready to use in rotation for waxing (although clearly bespoke artisan bike builders reckon wax is for amateurs…!) I’ve videoed it so I’ll see if I can upload it somewhere…

 
Posted : 16/01/2025 7:29 pm
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https://youtu.be/JS1nfGm-J18

 
Posted : 16/01/2025 7:48 pm
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LBS are going to send the derailleur back to SRAM for a warranty assessment (annoyingly this will take several weeks) . Not sure if they’re sending the chain and cassette too - probably not,  so that will obviously guarantee that SRAM reject the warranty and then the rest has to be sent off meaning another 3 week delay. :eye roll emoji. I might ask them if they plan to send it all but I’m fed up of doing all the thinking for them and to be honest hugely disappointed in the quality of SRAM top of the range stuff and the fact that the LBS seem to think that it’s acceptable that wireless shifting doesn’t shift some of the time claiming it’s a known issue, and when it does shift it’s noisy and not at all slick.

 
Posted : 18/01/2025 7:08 pm
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I’d just asking for a refund on the bike at that point and picking one without SRAM stuff on it.

My AXS stuff just never worked right from the get go and I couldn’t be faffed with the warranty process and not riding so I’ve just stripped it off and switched it out with Shimano stuff and I’m planning to sell the AXS kit to cover the cost.

 
Posted : 18/01/2025 7:58 pm
kelvin and sillyoldman reacted
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The shifting on the video is unacceptable for a new bike. I've had flawless shifting from GX and Rival level. It's easy enough on AXS for the bike shop to swap each part (cassette, chain, RD) with another (eg on a demo bike) to see if there a a single faulty part. If not then the bike should be rejected as surely that only leaves a frame issue. Or do you know anyone with AXS to at least swap the RD out? You wouldn't even need to pair the shifter if you have both bikes beside each other.

 
Posted : 18/01/2025 8:35 pm
oceanskipper reacted

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I’m going to go in there on Monday and get them to do all the troubleshooting to find out which component is at fault, then I’m going to try and insist that rather than send it away for warranty assessment that they replace whatever is faulty,  given that it hasn’t failed in use but has been like that since new… Having said that the derailleur is definitely the cause of the inconsistent actuation when the levers are pressed as I’ve seen the LED on the lever light up but no activity on the derailleur…

 
Posted : 18/01/2025 9:48 pm
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How about if you use the button on the derailleur to shift? One press to shift outboard; double press to shift inboard. Does it work ok then?

It does sound like a derailleur problem. All of our Rival and Force set-ups work perfectly. Red should be better still!

I'm fairly certain that Sram recommend wet lube (from my memory), but can't see wax making much difference as long as the chain links still have enough freedom of movement.

I might have a brand new Force mech that you could borrow to try?

 
Posted : 19/01/2025 8:58 am
 5lab
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If the mech isn't moving far enough over in total, it's got to be either the mech or the hanger. I'd be checking again that both are straight

 
Posted : 19/01/2025 10:08 am
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@stanley That’s a very generous offer, I could bring the bike to you depending on where you are possibly. Mechanically I think all levels (Rival, Force etc) are the same it’s just the materials that are different - although this is the new Red E1 which might be slightly different… Identifying the cassette as the cause by swapping derailleur would be helpful though. I’ll see what the LBS say tomorrow - bike is with them currently. I get the distinct impression that they are only sending the derailleur off to SRAM because I’m not satisfied with it and that they think the shifting is acceptable in the case of the problem demonstrated in the video  and a known issue which I need to wait for a firmware update to resolve, for the missed shifts. SRAM Rider Support say no such known issue.

To be clear the problem demonstrated in the video is with the MicroAdjust set to 13 (out of a possible 1-29 with default being 14). The up shift (to larger cogs) can be improved slightly by adjusting Micro Adjust to 12/11 but that introduces noise elsewhere and impacts down shift speed across the whole cassette. Anything above 13 just makes it worse.

I’ve tried to see if it misses shifts using the AXS button on the derailleur, but so far not. It seems to be a communication issue in that the signal to shift is either not received or just not processed for some reason. In any case the LED on the shifter illuminates and the LED on the derailleur doesn’t and no shift takes place. Happens once every 30-50 shifts I would say,  and is not lever specific.

The poor shifting could be the wax as you are correct @stanley, SRAM say use a wet lube of choice in their noisy chain troubleshooting steps. They don’t say wax is a problem though… LBS put UFO lube on it when they said it was a lubrication issue. I suspect derailleur, cassette, chain or frame. It’s 100% not a setup issue (hanger, limit screws or B gap) and they really need to do some proper troubleshooting by swapping components with known working etc to find the cause. As obvious as this seems to me I do think that they perhaps do not know how to do this effectively - troubleshooting is a skill and I find in my own workplace people simply do not know how to do it properly.  Perhaps they don’t have any parts to swap which could be the case I suppose. They ought to have a 10-33 cassette though as they swapped the 10-33 for a 10-36 when I bought the bike…

 
Posted : 19/01/2025 10:15 am
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Never before have I had a transmission that sensitive to what chain lubricant was used. I can’t even visualise how that would have an impact.
Noise, sure. But not indexing?

 
Posted : 19/01/2025 11:51 am
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I'd be returning the bike asking for a refund. Is your lbs the place you bought it from?

 
Posted : 19/01/2025 4:01 pm
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Yes bought from LBS and I'm not unhappy with their service in general, in fact they are really pleasant to deal with. I'm outside the 30 days now anyway as I bought the bike mid November but I don't want to cause a massive fuss - just get my bike working as it should be ASAP. I've only ridden it twice and it's been sat in my study waiting for an improvement in the weather! In fact I've just looked at the actuation count in the AXS portal and out of a total of 7000 actuations, only 1200 have been done while sat on the bike, the rest in the stand troubleshooting shifting issues!!!

I'll speak with someone senior tomorrow and see if we can agree a course of action that gets to the bottom of it ASAP without waiting for SRAM to process warranties piece by piece which is the bit I'm not keen on. Troubleshooting so we know for sure which component is causing the issue is my preference and then in my mind they should just be replacing the parts themselves but that will be up to them I guess. I'd be tempted to buy new myself  and then sell any warranty replacements but the cassette is bloody £350 and the derailleur £600...

Anyone with a SRAM road AXS system care to post a video of what it should shift like so I've got a comparison..?

 
Posted : 19/01/2025 4:42 pm
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@stanley - sent you a DM.

 
Posted : 20/01/2025 5:38 am

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Anyone with a SRAM road AXS system care to post a video of what it should shift like so I’ve got a comparison..?

I don't have Road, but have Force AXS XPLR Gravel if you want me to do that?  I can do it tonight when I get home.

 
Posted : 20/01/2025 8:38 am
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Thanks all. Derailleur is going off to SRAM so will see what’s it’s like when it gets back in a couple of weeks…. Hopefully perfect!

 
Posted : 20/01/2025 12:49 pm
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Here we go... a couple of videos.

This one is of my Summer bike. 46-33 / 10-36   A mixture of Force and Rival. Chain is noisy and slightly rough shifting as it is completely degreased, dry and devoid of any lubricant!

https://www.dropbox.com/scl/fi/3rivgug1pwpue91jjkfyx/ForceRival-new.mp4?rlkey=94engqozcjfpgdcryeuwnsb9k&st=0r3oftit&dl=0

This is my dirty gravel and Winter bike. 43-30 / 10-36   All Force components. Very well run-in. Dirty. Silca Synergetic lube. Interestingly, the rear derailleur is rated to a maximum 10-33 cassette. I changed to a 10-36 cassette; the derailleur is fine with it.

https://www.dropbox.com/scl/fi/hcvqasb4cix29l0l5nxdn/Forceold.mp4?rlkey=f8prb5iwsrjjpxkg3vp6fnztj&st=jw251tp0&dl=0

I've checked my "new spares" box. I have a brand new Rival 10-36 derailleur in there and a used Force 10-33 cassette. Happy to loan either/both for testing purposes.

 
Posted : 20/01/2025 6:53 pm
oceanskipper reacted
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@stanley you’re a legend, thanks for taking the trouble to do that. Very helpful. Derailleur is off to SRAM for warranty claim so I’m hoping a new one comes back soon and I’ll see how it goes. I’ve got a GX derailleur on a 10-50 cassette which shifts perfectly so with any luck I’ll get the same experience with a new mech…. Interesting that you have the 10-36 for hills - same as me. I watched a video earlier where the bloke was trying to get gearing so he could go up Hardnott Pass in Z2 or something. Man after my own heart!!! ???? laughing emojis…

 
Posted : 20/01/2025 8:37 pm
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Update - Derailleur replaced under warranty and shifting is now spot on. Haven’t yet seen a missed shift either so both issues appear to be resolved…

 
Posted : 27/01/2025 1:01 pm
vlad_the_invader, simondbarnes, Wally and 1 people reacted
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Great result - thanks for updating.

 
Posted : 27/01/2025 1:04 pm

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