Curious if anyone else has experienced this or has recommendations on potential fixes. I am running a SRAM Force AXS D2 drivetrain with a Red 10-33 cassette and a Red chain.
Shifting is fine across the entire cassette except for one jump. When actuating a shift to go up from the 14t cog to the 15t cog, the derailleur/chain fail to complete the shift. I can hear it riding on the edge of the cog, so the derailleur has clearly moved in response to the shifter being actuated. However, to get into the 15t, I ultimately have to actuate another shift, which jumps past 15t and into the 17t cog, and then down one to get into the 15t. Shifting down from the 17t to the 15t presents no issues.
The chain is relatively new and was stripped/waxed before installation. The rest of the drivetrain has about 25K km on it, always with a waxed chain. The teeth on the cassette do not look excessively worn, although it’s likely that the 50-15 is my most commonly used gear combo. Has anyone experienced anything like this, or can recommend next steps to correct the behavior?
Appreciate any thoughts.
The first thing to check is hanger alignment. It could be a slight twist which is difficult to spot. Replace it anyway, they’re pretty cheap. If you have the same issue with a new one, check the B limit screw and index again to make sure it’s spot on.
If you still have the same problem, it is possible that the cassette cog spacing isn’t perfect, you do get variances. I had a force D2 cassette that had a similar issue (very noisy on 1 cog) and swapping to a red cassette resolved it.
It’s funny, some people (like Peak Torque) have said that the individual cog adjustment that you get on Ltwoo and Wheeltop groupsets is pointless. This is a prime example of why it’s a great feature - sometimes even within a brand manufacturing intolerances are too great for everything to run smoothly.
Your last resort is a warranty claim with the SRAM distributer (you can’t contact SRAM yourself).
Appreciate the response. I should add that this is a recent issue - it started in maybe the last month? This same cassette has had no issues up to that point, which leads me to believe that it’s not a problem of spacing. I’ll check the hanger alignment for sure, that’s a great shout as it’s plenty possible that the bike has taken a knock or two.
Agreed completely about the advantages of individual cog adjustment. I miss that from the 11s SRAM Red eTap groups.
Ah I thought it was new. In that case hanger is #1 candidate!
I second @Glen_Murphy. A bent derailleur hanger is a very likely candidate.
I’ve had a very similar issue on a 10-33 cassette as well, and it was a B-screw adjustment that was needed. It’s worth double-checking the SRAM specs, as they vary quite a bit for each cassette size.
Check microaligment of the derailleur in the AXS app or using the buttons on the shifters. I had similar issue with Transmission AXS. I tried everything I could except that (did not occur to me that this could be the problem) and the problem still existed. Took the bike to my LBS, they have changed 1 position on the microaligment and it worked as it should.
25k is a lot of kms, wax or no. I would try a different cassette.
We see this relatively frequently with AXS stuff and usually attribute it to lateral chain wear as swapping the chain often resolves it. But given your mileage, it could be the cassette. I will often set the b-gap closer than SRAM recommends to resolve similar issues.
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Echoing others … Hanger alignment. I was dealing with a similar issue just last week. Nothing specific had happened to my bike, but all the sudden shifting from the 14 to 15 cog became inconsistent. After checking the usual suspects like micro alignment, I checked out my derailleur hanger. I didn’t expect it to be misaligned but it was. A couple of pulls and pushes with an alignment tool and shifting is perfection once again.
I find that 5th cog is always the first to get noisy on an AXS drivetrain.
Things to check if you rule out a bent hanger:
If you still have the plastic spacer widget it’s worth checking the b-screw as they do have a tendency to shuffle themselves out.
Also worth checking the top jockey while you’re poking around with the gap. If there is too much lateral play or the tooth shaping is worn too much then the chain has freedom of movement which messes with alignment.
I had one once with the top jockey bearing so worn it was wobbling like a clown bike. I suspect that you will have taken more care of things than that though!
Well, I’m eating some crow. Or maybe wax. I’m still having issues shifting between just two cogs. In my case, moving from the 13 to the 14. Hanger is aligned. B screw is adjusted. … Hopefully it isn’t the cassette. It’s got 12,500 miles on it, but that doesn’t seem like very much given I too use wax.
I’ll check out the jockey wheel …
Jockey wheels are fine. Double checked hanger alignment. It’s perfect. Cassette looks fine too. Weird.