AXS 12 sp work-around for Saris trainers?

Hey, question for you guys. Due to various limitations, I train mostly indoors.

Problem is, I’ve got a Saris H3 trainer and had wanted to go with a modern groupset on a new frame. Most tempting was AXS Rival or Force.

Talked with a super nice guy from Saris, and while he was super helpful, this isn’t a supported option. My next thought was go with Shimano (12 sp) but nope, not supported either. (and yes, this is why if you act now, you can get a H3 for a drastically reduced price - crazy low).

So, yes, I can try to find 11 sp options, but that just seems to be a soon dead end, I’d rather stick to 12 sp and AXS is possible.

My question is, anyone know of a way to set up a single cog on the trainer (tons of spacers on each side) and then I’d just stay in erg mode and not need to shift?

Wasn’t sure if there’s a way to get this to work with a regular cassette body and then single cog? Don’t see a way with the XDR / cassette block. Don’t think there’s compatibility with older SRAM 11 speed systems. Do SRAM AXS RD pulleys need a flat top chain? Just wondering about a Shimano freehub body, tons of spacers, single cog, few more spacers so that lines up right, then a non flat top chain and off I go, but just think I may be missing something / someone here knows this is a really bad idea.

This might just be a short term option (one season) then switch to another trainer that does support AXS 12 sp.

Thoughts? Concerns?


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I’m curious why a 12-spd Shimano group would not work. The cassette width is the same as 11-spd so it should fit and I’ve run a longer cage Ultegra-RX derailleur w/11-spd on a Saris H2 in the past (and I’m pretty sure the body of the H2 and H3 trainers are the same shape) so there shouldn’t be clearance issues.


What I had thought was it was about the teeth of that first cog, but nope, or not exactly. It’s the width of the cassette and they got a lot of calls (issues) with SRAM, Shimano and Campy (Campy is a no go too). I too thought the spec was the same, but I’m no expect on this sort of thing and that’s why I’m looking for an option.

He said there are people who haven’t had the degree of problems and others can get things to work well enough, but I just didn’t want to expect it to work, not be able to get support from Saris and then be stuck.

The impression I got from the conversation was, Saris built their trainers to a given spec and no fudge factor. Maybe some of their trainers can work with the required width / spec and others aren’t - either due to their trainer or the cassette or a combo. And others like Tacx or Wahoo have a bit more room?

But this supposedly impacts the M series and H series.

Just got this from their site (and looks like their trainers are back to normal price)

Bike Compatibility:

  • Compatible with Shimano/SRAM 8-11 speed cassettes

And then if you dig down a bit more:
12-speed systems cannot be used with the H3 Direct Drive Smart Trainer, as well as the CycleOps Hammer and H2.

There seems to be a fair amount of uncertainty over the issue of 12 spd on the H3. Saris sells a Direct Drive cassette body that is both XD and XDR compatible, so I am uncertain as to why this would not work.

Further, the standard freehub body is a Shimano 11 spd hyperglide freehub, so it should be compatible with 12 spd Shimano stuff.

Note the use of the terms “should be”…I have not tried either option on the H3. Mine got delivered this week, but I haven’t yet set it up. Further, I won’t be running 12 spd on it.

But if anyone is looking for a killer deal, the H3 is $399 with the discount code SCG-CDZ8SG-700.

Absolutely screaming deal for one of the best trainers out there…especially in ERG mode.

Yup, I agree, I love my H3 and so would prefer to extend its life / use a bit longer if possible and when I did upgrade, probably pass it on to someone who was on something older and not going to upgrade.

Just wasn’t sure if anyone had tried to do what I was talking about - single cog option with SRAM AXS somehow?

I have no experience with it, but there are solutions for single-speed conversions related to XD bodies. Here are just a couple examples.

That said, I’d be more interested in a simple SS conversion with your existing H3 HG body. There are numerous spacer options out there, so all it takes if finding the desired cog you want that also fits the chain.

Seems that at least two companies offer a 12-speed compatible version. It’s not clear that it is for MTB vs Road chains, so that might be worth check by them.

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Thanks Chad.

I figure if there’s no reason I can’t have the Force or Rival AXS RD and a say Shimano chain and cog, then life would probably be much easier.

Thanks again

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Based on this info I don’t understand why you couldn’t use sram road 12s cassette.

As for running single speed, we used to be able to enter singlespeed cx race by just zip tying the shifter. The question is more about the sram 12s chain compatibility with the cogs as I understand the rollers are slightly larger in diameter. I am not sure if you risk skipping gears under load, haven’t tried myself.

Having said that if you have enough space, the most sensible approach is to buy an inexpensive second hand bike with bog standard hg compatible cassette that you dedicate to it. For 100€ you can be set with a good enough one. Just buy your favorite saddle for it and a new handlebar tape and you are all set.

I bought a Saris H3 recently (due to the insanely low price) and I’m using SRAM Rival AXS. I just changed the freehub body to XDR. It’s little noisy but that’s probably because I need to do some adjustment on the derailleur.

OK, good to hear. When everything arrives I may be able to get it like you and if not, switch to the single cog option.


Just to circle back on this as trainer season is approaching. I mounted a 12-spd Ultegra 11-30T cassette onto my H3 trainer and when trying to shift into the largest cog the derailleur cage hits the body of the trainer and won’t go up. Not ideal but there’s still 11 other cogs that work fine.

Looking closer it appears that to work with existing 11-spd spacing the largest cog on the 12-spd sits further to the inside of the free hub than an 11-spd does.


Hey James! Writing in because I’m doing this exact same setup (Ultegra Cassette) with my Saris H3 and a SRAM Rival AXS system – how do you get the derailleur back up if the cage hits the body of the trainer? Do you have to remove the bike from the trainer? Does it seem like this risks any damage severe to the Derailleur?

I have that problem on one of my bikes and a gen-1 Wahoo Kickr - - though with 11sp Ultegra 6800.

Hey Andy, I’m running it with a Di2 derailleur not a AXS but I just start shifting back down the cassette. It behaves the same as if the limit screw was dialled in a bit too much, it wants to go up but can’t quite get there.