AXS setup for gravel & CX?

So one thing I’ve been wondering about with SRAM Wide 2x: from people’s experience, what’s the widest tire you can fit with a Wide front derailleur? Officially, SRAM says it supports up to 45mm wide tires but my Ultegra R8000 front derailleur fits that comfortably.

There’s some very chunky washboard gravel where I live (rural northern New England) and I’d like to try something like a 700x50c or maybe even bigger. The Lauf Seigla kinda has my name written all over it, but I’m wondering how fat a tire I can use with a 2x (for the 43/30 with 10-36 cassette potentially) instead of being locked into 1x.

Go 2x no question since you want to use the bike on gravel. 1x always will have big jumps between gears which results in cadence too high or too low, usually too low. And most people seem to underestimate how much grinding low cadence fatigues you. I think a lot of people doing 1x gravel that has become common now will be regretting it long term, I know some people who already had to switch from 1x to 2x.

I have seen some pictures of bikes where even 43mm Gk Sk’s looked tight. It was the clearance to the FD battery that was the issue.

I’m a road cyclist, but have gone with mullet 1x on my gravel bike and certainly have no regrets.

Yeah, I’m leaning towards Force XPLR with a 9-46 e*thirteen cassette. Seems to be the most flexible possible option.

This is what I’m running. It’s been great, no complaints at all.

Coming from a road background, I generally share this sentiment, but after racing gravel on a mix of 2x and 1x for the last several years, I’m a much bigger fan of 1x than I used to be. I used to be annoyed with the bigger gear jumps, but I don’t really notice it anymore and I think it’s made me a better rider. I just picked up a new bike with a Rival AXS 1x xplr group and I really like the cassette spacing. Are there situations where I’d still swap to 2x w/ a 10/33 or 10/36? Yep.

I did, and I’m so happy to be back to 2x!

Had my 1x gravel bike 3 years with no regrets. Have a bunch of friends also running 1x and never heard any complaints. It’s really just personal preference.

Are you guys @jwellford @FergusYL using the flattop chain?

I believe the XPLR (rear) group set is not compatible with anything other than itself, like wise with Eagle in that an Eagle chain cannot be used in an XPLR cassette.

Chainrings I believe are compatible across ranges but the rear needs to run within its own range.

I do know that the eThirteen 9-45 is used (not read as compatible) within the the XPLR range, which I assume, the flattop chain is used because the XPLR deraileur is being used.

SRAM site says not to use an Eagle chain with an XPLR cassette nor deraileur.

Any comments to add?a

@SirDAN I’m using the Eagle X01/XX1 chain. It works flawlessly with the XPLR derailleur, with the added bonus of getting to use the longest lasting chain on the market by far.

My impression is that the flattop chain would not work with the eThirteen cassette, and flattop is limited to its own range when it comes to cassettes. But derailleur doesn’t matter even if SRAM says it does. Basically, using the eThirteen cassette and Eagle chain gets you most of the way toward a “mullet” drivetrain, without having to buy an AXS mountain derailleur.

My experience is that you can run eagle chains on any sram 12sp setup. I understand that the flat top chain cannot be run with eagle stuff, but I’ve never tried it.

I wax my chains and have multiples in each length and variety to minimize the frequency of waxing. The main length for my mrb eagle matches my new gravel 1x xplr setup, so it’s nice to be able to swap. I also find the flat top chains don’t seem to hold wax as well and don’t run as long between waxing.

@jwellford yeah, thanks, I have a similar impression that the flatttop chain is tied solely into the XPLR 10-44 cassette.
Reading on the SRAM support site, there is no definitive answer to whether an Eagle chain can be used via the XPLR deraileur, emphasis is put on chain and cassette needing to be from the same range.

View the differences between Eagle and XPLR (1).pdf (66.6 KB)

I do notice that the XPLR cassette is mounted on an XDR hub whereas Eagle is on XD and eThirteen can be mounted on both. Am I correct in that assessment?

You base this on self practical use? Dont specifically want to go destroy a XPLR deraileur unnecessarily.

I ran the “mullet” drivetrain on my previous 11spd Force/Rival mechanical groupset with the eThirteen 9-46 cassette and long cage deraileur no issues, before I was bike-jacked.

The conundrum here is that it’s sensible to buy the GX AXS trigger and deraileur set as the deraileur is not that much cheaper on its own from the set.

@grwoolf do you run your Eagle chain on a XPLR cassette? Without any problems? From the SRAM site and anecdotal experience, there is a difference between an Eagle chain and Flattop chain and similarily with the two cassettes, and sound advice is given not to run an Eagle chain on a XPLR cassette and vice versa.

What has been your experience?

Eagle and eThirteen are both XD, and can be mounted on XDR hubs with a spacer. XPLR is XDR only.

Mine and others’ yeah. Worst you could do is prematurely wear out some pulley wheels but I don’t think this is a concern.

If your bike came with XPLR the value play is to swap to an Eagle chain and eThirteen cassette, but if building from scratch I’d say there’s no big reason not to go full SRAM mullet. I guess the XPLR derailleur is cheaper, but having the Eagle AXS derailleur opens up 10-50 and 10-52 cassette options. That could be nice in many scenarios. As to whether you should get the trigger with it, well, I guess you could sell it or keep it in case you ever build a flat bar bike.

Would it be really silly to add the Red Aero x1 crankset in a mullet setup? So 48T front chainring, 10-50T eagle in the back. No other reason besides this is the only one crankset I can get my hands on at the moment, plus I think it would probably look pretty slick.

Question is, would that even work?

Maybe someone else knows better, but I don’t know why it wouldn’t work. I run a similar AXS mullet setup with Force 40 front and 10-50 Eagle cassette. Works great.

I just put a 1x Force crankset 40T (GXP but Dub would work) on my mullet. Works great. Why can you only find Red Aero? Lots of Force out there too.

Would like to introduce you to Keegan Swensons Stigma

Hope you’ve got a similar W/kg :wink:

Haha well that’s better than I thought! Thanks for the link. I was just worried that the aero chainring might have a slightly narrower chain line or sth.

Not the same w/kg as Keegan I’m afraid but I live in the Netherlands and will use this setup for beach racing, hence the aero and big 1x chain ring consideration.

Yes, I think Keegan Swenson used that setup for Unbound Gravel. Although I think a 48-tooth chain ring on a gravel bike is complete overkill, at least for us mere mortals. For comparison, I have a 42-tooth chainring on my aero road bike (1x12), and I spin out at 65 km/h. Do you need to be faster than that? On a gravel bike?

But especially when flat, you don’t need taller gears. Even on the road, unless you are a very good sprinter, when the terrain is flat, I don’t think you need such tall gears. And I don’t think Dutch mountains (= wind :wink:) require such a small gear either. Or are you planning on taking the bike to places with proper inclines?

Yes, you’re making some really good points here, I will consider this very carefully. I could possibly wait until I find a 44 chainring setup, I’m really struggling with the availability. Plenty of 40T’s just no 44s.

At the same time I could get my hands on heavily discounted red aero 48T crankset with a PM (750 eur). Let’s also not forget the looks, it will look really great on my frame :slight_smile:

I have 3 road bikes and a XC rig already, now I’m just thinking of building a sort of jack of all trades bike - one I could use in North Holland (with an epic tailwind in the winter) but also take it to Belgium, Austria, Italy etc. where hills can be really steep. I know it sounds like an overkill but 48/10 at 90 rpm is approx 55km/h, at the same time 48/50 at 80 rpm is 10 km/h.

I’m only afraid that if I needed a rig for some serious climbing I won’t be able to easily swap the chainrings on the red pm setup as the direct mount chainring is integrated with the pm.

Anyway, I’m thinking out loud - thanks for your comments as this is really helpful!