Gravel bike -- 1x vs 2x


#1

I’m looking to build up a gravel bike to use for training purposes, and I am debating 1x vs 2x drivetrain. 1x offers simplicity and weight advantages, but creates challenges putting it on my wahoo kickr for TR workouts give the 12spd derailuer vs 10 or 11 speed cassette. I want the option to use resistance mode to keep the workouts more entertaining when on the KICKR, but realize shifting is going to be a real issue with a 1x set up. I wish wahoo would catch up with the 12sp formatt…

2x should offer some better range, but adds weight and complexity to the bike–but works better with the KICKR. I’m leaning 2x, but interestedd in other thoughts.

I’m also debatting 172.5 vs 175mm cranks. I believe I’m settling in on 175mm cranks, as MTB ing is my primary interest and that is what is on all my other bikes, and I’m 6’ tall. I do intend to use this bike a fair bit on paved roads, but is there any reason I should consider 172.5 for a CX/Gravel bike?


#2

Also interested in this discussion. My current bike has a compact crank, and i don’t think i would like a 1x drivetrain, but i might like a subcompact crank. Mostly i ride fireroads and smooth-ish singetrack, and not sure about the jumps in ratios on a 1x cog set. One benefit of 1x, and the main reason it is appealing to me, is the larger clearance it affords in frames. For my next frame, I’d like TAs, 700 x >45, and would prefer the possibility of running 2x. Oh, and preferably steel. Don’t need/want carbon, can’t afford Ti.

The shorter crank will make higher cadences easier, depends on your riding style. i am a couple inches shorter and would definitely go 172.5. May also depend on how much BB drop you are planning for the frame.


#3

Why not just go 1x11? Both of my bikes are 1x (50tx11-32 road, 44x11-40 gravel) and have never been left wanting more on either. If I need more range on road, I can go 11-36 or even 11-40.

Seems like 1x11 would solve your issue completely—1x for simplicity, 11 speed for Kickr compatibility.


#4

I use an older CX bike with a compact 2x for the bulk of my riding. Where I live we have a significant amount of gravel roads, but there’s still a decent amount of pavement linking them together so I personally feel I would be giving up a lot of speed going 1x since there are a few segments where I’ll get up to 30 mph going for a strava segment KOM.


#5

If I go 1x, I would need 12 spd to give me the low end range to get up steeper climbs without giving too much up in the descents–being a 2.8 to 3.2 w/kg rider is my limiter. I’m working on that, but training effectively will be a big part of that…


#6

I have a gravel/CX with a 2x setup. I like it for when my legs don’t show up and I have all the extra gears to assist with the effort. The argument the coaches make on the pod is, why not have more gears? If you need them and don’t have them, it is much slower then the weight they add.


#7

I dunno man, if you have a wheelset with an XD driver you could get a 9-46 cassette which should help cover you on both ends, especially since you’ll be able to use a smaller chainring. With a 40t chainring, a the 9 would put you close to the same ratio as a 50x11, while the 46t on the cassette would give you an insane climbing gear.

40x9-46 would give about the same range as running 50/34x11-40.


#8

I have a gravel bike and I put a 2x11 and really with I would of done 1x, agree that 1x12 would be the best, I didn’t realize the KICKR wasn’t compatible with an eagle, I thought it was!!! I’ll have to look into this a bit more for my MTB setup, granted I haven’t seen 12spd drop shifters…but either way one thing you may not have considered is a subtle benefit from a 1x is you have an extra shifter that can be used for a dropper. It may sounds silly but for long downhills or rough downhills is super nice to be more aero, lower CG and its super slick. The SWORKS diverge comes with this setup, and keep in mind for internal routing the frame must be open at the bottom bracket…either way, I want a dropper on my roadie now…


#9

Depends where you ride. For most midwest riding 1x is all you need.

As for the wahoo kickr…never used it, BUT! If you go 1x you don’t need 12 speed. Or even 11speed. 10 speed is just fine.

I rode DK200 on 1x10 (40 front, 11-34 back) in a little over 13.75 hrs. No prob. Went back to KS this summer w/ same bike, same setup and rode 102 mile race in 5.25hrs. So 1x10 is good enough for mediocre times on midwest gravel.

If you have more serious climbing to deal with maybe then 2x is the way to go.


#10

One by is really simple and works great on my gravel bike - BUT - when running smaller rings in front for easier climbing you do spin out on faster sections. I ran a 26 front ring at Rasputista gravel race two years ago and climbed everything except some deep mud and snowy sections in Cyberia - unplowed keep Road in April in Vermont.

I am a back of pack rider but passed a lot of people on climbs but when it got fast the folks with higher gearing repassed me and left me in the dust but I would catch up again on extended steep climbs - I probably could have kept up better with a 2x.

But in hindsight I wonder if using a bigger ring for more speed and just dismounting and walking on the 17% grade sections would have given my legs a rest. It was funny cause could see people walking and slowly catching them but took several minutes to close 100 yards - wonder if I got off and walked if my leg muscles would have been fresher and able to charge harder on flats afterwards.

****** One thing I run into with 1X in Zwift often can’t peddle fast enough on fast downhills to keep up and power goes to zero because can’t get cassette turning fast enough with small ring in front to keep pressure/power on trainer.

But salsa Cutthroat with 10-42 sram rear cassette and 26 or 28 front ring makes climbing mountains like Cadillac Mountain super easy - can climb with normal cadence and still keep watts quite low like easy L2 power zone.

This makes great recovery ride bike even in very hilly terrain cause it is geared so low you can spin up hills vs muscling up.

I love my geared Down bike - finished Rasputista 4000 plus feet climbing and my legs weren’t toast at all - but you do end up watching the other riders dissappear on anything past 18 - 21 mph sections cause you are spun out at 100 plus rpm - but you can climb like a goat all day and not feel it.

With 2x if you can get gearing low enough to climb effortlessly then can have 10-16 more teeth on front ring when you shift not to get left in dust when pace picks up.

(My cutthroat has 1x11 mountain bike cranks so can run 24 or 26 ring up to 40 something ring - just have to change your gearing/ring to match terrain you are riding - 1 have force one model two years old and cranks are sram MTb cranks - have to check cranks on other builds of cutthroat as run mtb cranks limited to like 30 or 32 for smallest ring - so would have to change cranks to get super low gearing I am using in mountains)

I also have 1X on Fatbike run 26 tooth front ring for hills in snow - works great on climbs but my friends with 2x can shift to big ring on faster trails and once I spin out they ride away from me - but I get good high cadence drills peddling 110-12- rpm trying to keep up. :wink:


#11

It’s not the number of possible gears you have (11 vs 12) that determine your high and low-end range, it’s the actual gears at either end. Are you thinking of putting Eagle on a gravel bike?

You can get crazy wide range cassettes now, and you can play around with chainring sizes for 1x drivetrains too. E-Thirteen has a 9-46 11-speed cassette!

I run SRAM 1x for gravel in the northeast USA. On steepest, most technical routes in Vermont use a 10-42 cassette with a 38 or 40t ring. I’ve never needed more high-end (descent) gearing than that. And the climbing gearing is pretty good at easier than 1:1.

I’ve toyed with the 9-46 cassette idea, but then I’d be trading off even bigger gaps for some extra range that I maybe don’t usually need.

But, to the Kickr part of your question - yes. If you’ve got 1x gravel/climb friendly gearing then on a trainer in non-erg mode you’ll have trouble getting a hard enough gear for tougher intervals or low cadence/high force.


#12

My vote is:

1x 11 speed with 9/46 cassette. Change front chain ring depending on the course.

I took my cross bike to Maui with the above setup. I had plenty of gear for the flats/slight downhill and enough to go up Haleakala.


#13

@Nate, I’m intrigued, what front chainring did you run with a 9/46 cassette for Haleakala?

My vote for gravel is 2x, but we have such varied terrain here, the ride can very from sitting in a 40+ km/h bunch to grinding up a 22+% gradient climb. I like the CX gearing for gravel, 36/46 with a 28t cassette.


#14

What are you using that allows 1x12 for drop bars?
Nothing I can think of is available right now.

Sram may work with eTap and the upcoming Wireless Eagle, but I can’t think of a drop bar option other than the Campy that’s 12 (and that is not compatible with wide range discussed here).


#15

You can easily get the same range of a 36/46x11-28 with a 46x11-40.


#16

Range isn’t the issue as much as the bigger steps on the jumps. Works fine in MTB because of the variation in the riding.

More steady state on gravel and road sections leads to needing to work a wider functional cadence range.

You loose the smaller steps and subtle changes of 5 rpm and end up with 10-20 rpm depending on the exact cassette.


#17

I’m sure I can, but not with a road setup? What’s the largest cassette a long cage Ultegra RD can take? Not really keen on switching to MTB bits.


#18

I’m hoping to see a 1x12 gravel setup with a 10-45 cassette (like the pending Shimano XTR 12x) for better spacing.

Oh heck, that might be the other 12s option coming soon too. Di2 road shifter and the XTR derailleur.


#19

Check out the Wolftooth road 1x options. Can’t remember the specs. I will grab a link.

  • 11s Cassette Compatibility:
    • 11-32: Not Required (GS medium cage rear derailleur works)
    • 11-36: Single or double chainring (be sure to not exceed the derailleurs capacity)
    • 11-40: Single or double chainring (be sure to not exceed the derailleurs capacity)
    • 11-42: Not supported
    • 10-42: Not supported
  • Optimized for use with 11-36t, 11-40t, and 11-42t 11-speed cassettes
    • Will improve performance with 10-42t 11-speed cassettes, but not to factory levels

#20

Where I do my gravel rides at least, whether it’s a 2x with 36x28 or 1x with 46x40 neither are nearly easy enough climbing gears for the steeps.

Your expected terrain is huge factor in these gearing decisions.