Retro fitting AXS XO Transmission. Not working :(

[Maxed280]

Good evening all, First post here at my whits end.

Installed a SRAM XO AXS Transmission to my bike today along with a new chain. All was going well until i tried the setup through AXS app that told me the wrong chain length .

Anyway the real problem is when i set everything up following SRAM instructions the transmission wont stay on the "setup" gear and jumps down 1 gear no matter what i do with it. Repeated from scratch several times and still same outcome.
Since it jumps down one from setup gear all other gears are -1. So will not change into 12th and chain falls off cassette as its able to go lower than gear 1.

I'm not very experienced with bike parts but can follow these simple instructions. Bike is a non Pro from early 2025.

I have read that maybe a spacer is needed behind the cassette? A little lost what the next step will be so any help would be appreciated so i can get back out on this beast. I maybe purchased the wrong parts or need to replace something else here i have no clue.

 

[Gauss Guzzler]

That looks like an Eagle cassette, which isn't really compatible with T-type chains. Otherwise, it should be 120 links, key position A, and 7th cog (6th gear, 24t).

If you change cassettes, note that the XS-1270 fits Shimano 11-speed drivers, which is probably what you have and the XS-1275+ fits SRAM drivers.

 

[Astro66]

That looks like an Eagle cassette, which isn't really compatible with T-type chains. Otherwise, it should be 120 links, key position A, and 7th cog (6th gear, 24t).

If you change cassettes, note that the XS-1270 fits Shimano 11-speed drivers, which is probably what you have and the XS-1275+ fits SRAM drivers.

Correct. That's an PG cassette. You need an XS cassette. That will never shift properly.

As stated above. The XS-1270 fits a HG Hub. All other XS cassettes fit a XD Hub. So check your hub.

 

[Maxed280]

Thanks guys super helpful and getting somewhere now. Was lead to believe it would have been a easy swap but seems not.

Current cassette is a SRAM PG1230 so i have a HG hub. Fully understand about the chain difference.

Will changing the cassette also fix the alignment issue I'm having? As explained above when i set to 7th cog with 1 spin of the crank jumps to 6th cog.

 

[Maxed280]

That looks like an Eagle cassette, which isn't really compatible with T-type chains. Otherwise, it should be 120 links, key position A, and 7th cog (6th gear, 24t).

If you change cassettes, note that the XS-1270 fits Shimano 11-speed drivers, which is probably what you have and the XS-1275+ fits SRAM drivers.

Also you mention Setup position "A" the website says B. 2 times now im getting conflicting info from website/App. Do you use A?

 

[nowayfra]

As far for the gear alignment, inside the AXS-app there should be an option to 'micro adjust' the derailleur position.

 

[Maxed280]

Unfortunately micro adjust is not enough to move 1 full gear that it's jumped

 

[nowayfra]

Unfortunately micro adjust is not enough to move 1 full gear that it's jumped

I see from your pics its indeed some unusual large distance between smallest cog and frame dropout. If you have a used HG cassette lying around you could dismantle it and use one of the distance rings between the cogs (they sould be standard for all of the non ultra-highend shimano cassettes and come in plastic or aluminium) and use it as spacer to get some offset. But this would be a tight fit since with HG cassettes the lowest cog sits separately on the tip of the freehub so in worst case it won't grip, so you would need to grind down the spacer until it fits (and hopefully be in range of the AXS micro-adjust).

 

[VWsurfbum]

No actual experience here, but from what I have read,

• Unique Physical Dimensions: T-Type Flattop chains have larger rollers and are taller and thinner (both internally and externally) than standard Eagle chains. The cassette and chainring teeth are specifically machined to fit these oversized rollers.
• System Interdependence: Using a non-Flattop chain on a T-Type cassette can lead to chain jumping under load and premature wear of expensive components

So if you keep your standard chain and cassette, once aligned, that should work. The chain needs a specific cassette, not foat chain on an old cassette, that won't work.

 

[Astro66]

So if you keep your standard chain and cassette, once aligned, that should work.

That's the problem. The new cassette sits 2.5mm further out than the old, and you don't have 2.5mm of micro-adjust in the derailleur. So you cannot get alignment. People have used spacers, but then you get less threads engaging on the hub, and this weakens the connection. There are reports of it stripping under load.

He really needs the XS-1270 T-Type cassette, which will fit correctly on his HG hub. Aliexpress have that cassette for sale for just over 100 pounds. Then the derailleur will align correctly. The T-Type chain will engage properly, and he'll get good life out of his components.

 

[Maxed280]

That's the problem. The new cassette sits 2.5mm further out than the old, and you don't have 2.5mm of micro-adjust in the derailleur. So you cannot get alignment. People have used spacers, but then you get less threads engaging on the hub, and this weakens the connection. There are reports of it stripping under load.

He really needs the XS-1270 T-Type cassette, which will fit correctly on his HG hub. Aliexpress have that cassette for sale for just over 100 pounds. Then the derailleur will align correctly. The T-Type chain will engage properly, and he'll get good life out of his components.

Awesome explanation there. I have purchased XS-1270 today and will report back shorlty.

That 2.5mm is what im missing it seems.

 

[Maxed280]

100% was the issue. New cassette fitted XS-1270 and a small micro adjustment and works flawlessly.

Full power upshifts with ease

Thanks for all the help guys

 

[High Rock Ruti]

Thanks guys super helpful and getting somewhere now. Was lead to believe it would have been a easy swap but seems not.

Current cassette is a SRAM PG1230 so i have a HG hub. Fully understand about the chain difference.

Will changing the cassette also fix the alignment issue I'm having? As explained above when i set to 7th cog with 1 spin of the crank jumps to 6th cog.

High Rock Ruti

Easy yes.....inexpensive no

Warm Regards Ruti

 

[randomusername]

There's a thread elsewhere on here about using AXS transmission with a non transmission cassette - you can either space the cassette by ~2mm, which isn't possible on the HG cassette, or you shim the jockey wheels with washers.

I did the latter - I've got an Eagle XX-SL T-Type mech with the supplied (PG1230?) non-Transmission cassette and the non-Transmission chain, and it shifts perfectly. I wasn't happy with the length of the jockey wheel bolts so bought some slightly longer ones, but that was more for my peace of mind than anything else.

 

[Astro66]

or you shim the jockey wheels with washers.

The only thing with this, is the jockey wheels aren't centred in their cages, and there will be a significant side loading, which the jockey wheel axles were not designed for.

For me, it's not worth it. As I pointed out. The correct XS-1270 cassette is only AUD$200, which is £100. The chain is AUD$70. And I fitted a standard alloy 34T chainring, as this creates less wear of the chain, and the alloy chainring was only AUD$10, and I have put over 1500km on it.

The SRAM AXS Transmission system just works brilliantly. I don't think it's worth not having the correct matching parts.

That said, KMC have just released a Gold version of the T-Type Flattop Chain. I am definitely going to try it, as I have a Gold theme going on my Amflow.

 

[randomusername]

The only thing with this, is the jockey wheels aren't centred in their cages, and there will be a significant side loading, which the jockey wheel axles were not designed for.

The jockey wheels aren't centred in their cages, but they are supported just the same by the washer which is against the body of the mech, so there will be no "side loading". The jockey wheels are just used to align the chain on the cassette - all of the load/tension is on the chain between the cassette and the chainwheel.

I'm not arguing that in a perfect world, you should replace the cassette, chain, mech all at the same time to the T-Type parts. But - despite what SRAM tell you, you can make a T-Type mech work absolutely perfectly with your existing parts and replace them when they wear out over time with the correct ones.

If anything SRAM have made it a different offset on purpose to force you to spend more money...

 

[Astro66]

The jockey wheels aren't centred in their cages,

The jockey wheels are exactly centred on their axles in the cage. This is a photo of a spare T-Type cage I keep.

So if you are shimming them 2.5mm inwards, to align with the cassette sprockets that are 2.5mm further inwards, then they will no longer be in the centre, and you would be forcing the cage wider. Both of these facts are not optimal for best performance and life of you transmission. But indeed you have saved a few bucks.

If saving a few bucks is important to you, then well done. But tolerances for perfect shifting are tight, and doing that would allow for more movement of the chain within the cage and thus more movement where the chain engages on the sprockets and ramps, and the jockey wheels would not be rotating centred on their axles.

 

[randomusername]

The jockey wheels are exactly centred on their axles in the cage. This is a photo of a spare T-Type cage I keep.

So if you are shimming them 2.5mm inwards, to align with the cassette sprockets that are 2.5mm further inwards, then they will no longer be in the centre, and you would be forcing the cage wider. Both of these facts are not optimal for best performance and life of you transmission. But indeed you have saved a few bucks.

I meant the jockey wheels aren't centred in the cages after you have shimmed them...

But it really makes very little difference as they are shimmed equally top and bottom, and the two sides of the mech cage are bolted together via the jockey wheel bolts - so as long as the bolts are long enough to engage properly, everything is parallel and will work just as well as it did before.

I believe the offset of the cassette on the freehub is different between XD and HG - so you don't need to shim the jockeys 2.5mm - ~1mm (a couple of standard washers) is enough for it to become within the micro-adjustment of the mech.