Sram etap with 13 speed cassette

Probably somewhere this year I have the possibility to buy/build a new bike. I would like to build a N=1 bike. So I want to go 1x with an aero gravel bike. Have 2 set of wheels (650b and 700c) have 2 cassettes (10/36 and 10/46) with wippermann connex chains.

But for this build you normaly only have one option to go with the Rotor 1x13 groupset.

Now I’m wondering if it’s also possible to get a sram etap rear derailleur working with a Rotor 1x13 cassette.

Anyone with idea’s or knowledge about this combo?

I’m going to go out on a limb here and say you have no chance.
The system is programmed to take a certain number of sprockets with eTap having 11 and eTap AXS on 12. To run a 13 speed cassette would require new firmware to allow access to all sprockets; can’t see SRAM doing it just yet.

Just my thoughts and wish you luck with it



Thus far it looks like a Rotor derailleur is the only option.

What Adam said.

Short answer: No
Long answer: Nope.


“Soooooo… you’re saying there’s a chance.”



I don’t see why you need 13 speed. Go 2x if you want lots of range with finger steps in between or 1x and sacrifice range or have bigger steps. (Maybe even seal chain rings).

FYI, people really overestimate how much speed they give up by using a smaller chainring. Increasing cadence by 10 rpm will speed you up quite a bit in your hardest gear. And how long do you really need to maintain that top speed?

Size your gears for the easiest gear you need since dropping cadence too far will cause you to stall out or tire out. Then pick cassette and chainring combo that gives the best trade for gear spacing and top end.

Aero gravel bike?

Lots of people, myself included, don’t like changing front chain rings for many reasons. Rotor’s 13-speed cassette options are close to the 14 gears that most 2x11-speed drive trains give you, that you don’t really lose much.

Perhaps he is referring to the 3T Exploro.

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Having spent a fair amount of time working with SRAM AXS and some time working with and riding Rotor UNO… I really just can’t recommend UNO right now. It’s not bad to work on, but I can’t get on board with the ride. The ergonomics are wacky too. Shame, really - I love so much of what Rotor does. Get AXS. Both Force and Red are nice, though I will say the Red drivetrain is substantially quieter than the Force version. My suggestion would be a Red 10-33 cassette, Red chain, and Force everything else. That way you can have a power meter and several chainrings to choose from, since the Force PM isn’t built into the chainrings. It’s really a very good system, and SRAM is doing some cool integration projects right now with data collection on your cycling computer.

But to answer your question, you won’t be able to make a SRAM eTap derailleur work with a 13sp cassette. It is possible to make a SRAM mechanical derailleur go 13sp, but believe me when I say it isn’t worth the trouble or money. Just do the AXS thing. Or the 11sp mechanical thing.

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11s mechanical really is just very good isn’t it. Regardless of brand. Probably the “golden age” of groupsets where pretty much everything is compatible.

Stock up on your 11s rim brake spares and consumables people… you’ll be sorry when they’re gone!

My point is people always want one more gear. Wasn’t that long ago that 2x10 was the best available.

Does 1x12 vs 1x13 really sacrifice so much range that it’s not good enough? Or do you deal with bigger steps between gears to get that same range?

Or do you learn how to raise your max cadence a bit and have the range and smaller steps? That’s free and gives you more flexibility on your drivetrain.

Or else you need 2x12 to get same or more range than 1x13.

the other reason that the 13 speed Rotor setup won’t work - your regular wheels. From what I understand you would need to buy the Rotor wheelset which is specifically designed so that their derailleur does not rub spokes. No go for multiple reasons.

Just go SRAM 1x12 new AXS etap. Pricey but I think it will be awesome for gravel. I agree with you that 1x rules for simplicity. I think for road we will need 1x13, but for gravel i think 1x12 will be awesome. Full disclosure - have not tried it yet. Ordering my new Trek Checkpoint with SRAM EAGLE AXS etap this month!

Perhaps this is pedantic, but you have to use a Rotor hub, and the hubs are available on their own. A local wheelbuilder can put that hub in your existing wheels, whatever they may be. It’s an extra step and it limits the ability to swap wheels between bikes, but since the goal here is to only have one bike It’s probably not an issue.

ya i don’t know the exact details of the wheelset/hubs from Rotor. I just knew when I was briefly looking on their website you could not just throw any old wheelset into the mix. it’s like you said, one more step (or should I say purchase) . . . and I was out.

I think so. Rotor offers 10-36 and 10-39 cassettes for roadies, which strike a nice balance between having closely spaced gears at the top end and decent gaps at the bottom. The 10-39 cassette has the exact same gearing as SRAM’s 10-33 cassette, plus the extra 39 sprocket. This gives you a 390 % gear range, which is in between 50/34 + 11-30 (400 %) and 11-28 (374 %).

The 10-36 cassette has slightly less range than the 50/34 coupled to a 11-28 cassette (360 % vs. 374 %). For some inexplicable reason SRAM does not offer a 10-36 12-speed cassette, if they did, that’d be the one I’d put on my next bike. What gives, SRAM?

But I’m planning on getting two chain rings, a 40-tooth chain ring if it gets hillier and/or I am on more relaxed training rides through the mountains. And a 44-, 46- or 48-tooth chainring for races.

The trend goes in the opposite direction, actually: my current mountain bike has 3x10 = 30 gears. The next 11-speed generation of drive trains either came as 2x11 or 1x11. But even 2x11 has less range than my 3x10. 12-speed drive trains are practically all 1x. Yes, you can get a 2x version of Shimano’s 12-speed MTB groupsets, but I don’t remember ever seeing a bike in 2x12. That 2x12 bike would have a larger gear range than my 3x10 — but it’d also have larger gaps, too. :man_shrugging:

For road bikes, you have the same trends: triple chain sets are a thing of the past on road bikes, too, and you can get more and more fast riding done on 1x. Bike manufacturers have to build their bikes for all eventualities, i. e. customers living in the alps and the Netherlands alike.

I currently have more gear range than I need (50/34 and 11-32), but nevertheless, I do not want to go for a more closely spaced cassette: I often use 50:25 and occasionally 50:28 on rolling terrain, and on a 11-28 cassette, I’d torture my Shimano drive train a little too much to use those gears regularly.

The largest range you can get from SRAM with 1x12 is 330 %, which is kinda tight if you live in a mountainous area and you want to keep up with really fast people. That describes my situation. With 360 % I’d be good, and 390 % would give me slightly more range than I need right now.

If I get the 10-33 cassette on my next bike, I’ll definitely need two sets of chainrings.

Yes, I want to go for the Rondo HVRT. A road bike but with the option to put in 650b wheels with 47mm tires. And the option to change the geometry via the “chip thingy” in the front fork.

I want to go 1x13 for the simplicity. No one I now, including myself changes gears front and rear derailleur to always get the smallest jumps. Everyone just changes at the rear derailleur until they run out of sprockets and then they change gears at the front derailleur. So smaller steps with 2x is kind of a non discussion in my opinion. Especially when you consider the 10/36 jumps (10, 11, 12, 13, 14, 15, 17, 19, 21, 24, 27, 31, 36) next to a 11/28 cassette (10, 11, 12, 13, 14, 15, 17, 19, 21, 23, 25, 28)

I want to buy 2 rims from Light Bicycle. And let them build up with the Rotor hubs here in the Netherlands

I live in the Netherlands. So my philosophy with this bike is that in the Netherlands you can have a N=1 bike.

First of all the 2 wheelsets. Then 2 cassettes 10/36 and 10/46 with a 46 or 48 chainring (still debating about 46 or 48). With a 46 and 10/36 you are in the compact range which is fine for everything on the road in the Netherlands. With the 46 and 10/46 and 650b I can use that for the gravel road in my area, which is a little bit hilly.

This 46 and 10/46 combo can also be used for the singletracks in the Netherlands. In my opinion you don’t need a MTB per se in the Netherlands. 99% of the trails are do-able with a gravel bike. You probably wouldn’t be as fast as an MTB on the trails. But I don’t care about that. I just want to have fun.

And when I go to the alps. I can take my 700c wheels with the 10/46 cassette and spin up the climbs there.

With this I also want to use wippermann connex chains of the quick links to easily swap the chains and cassettes.

So for my use case the Rondo HVRT specced as explained above would be a N=1 bike.

This is a good point: if I had a road bike in the Netherlands, I’d have thrown away my small chain ring already and would ride around with a 11-32 cassette or equivalent as well as a suitable chain ring (perhaps 40 for commutes with my kid and 50 or 52 for fast road rides).

When I follow the Japanese coastline, it is also more or less flat, with the occasional bridge or small undulation breaking up the monotony.

Stupid offtopic question: how do you go road biking in the Netherlands? The cycling infrastructure is excellent in my experience, but solely geared towards everyday riders. (When I was there, people could immediately tell I wasn’t Dutch, because I was the only person wearing a helmet :laughing:)

That sounds like an excellent choice. Why don’t you leave a post in the forum telling us how you like it? Doubly so if you opt for Rotor’s 1x13 groupset, there are very few reviews out there from actual customers.

The cycling paths in the cities are mostly used by commuters. But it’s easy to get out of the cities, even Amsterdam. Outside of the cities you mostly have seperated car/bicycle lanes. So you can hammer through the landscape. It will take me from my town 15 minutes to cycle through flat farm lands and over dykes. Or 15 minutes for some rolling landscape with forests. Or 1 hour to get to an actually hilly part.

And yes, only people on road bikes wear helmets. Commuters never do (exceptions excluded).

I will! I’m waiting for my employer to adapt an law which came into practice in 2020. With this law it very cheap for employees to buy/lease new bikes. This way the govenment wants to support people who take the car to work for 15 rides to take the bike.

For example. An e-bike of €2500 would cost an employee with this law €5,- a month for 4 of 5 years. And after the 4 or 5 year they can pay the rest value (which is not much) to take full ownership of the bike. With this example an €6000 or €7000,- road bike would cost you €15 a month.

So I can go all out to create my N=1 dream bike. When I have it I will thoroughly review it.


I’m very much looking forward to seeing the finished product and hearing about your experience with it! Please do keep us posted.