Should You Consider a 1X Drivetrain on Your Next Road Bike?
Jim’s Tech Talk
By Jim Langley
In case it’s a new term for you, “1X” is slang for a single-chainring drivetrain without a front derailleur and without front shifting, too. “2X” is slang for a double-chainring drivetrain with a front derailleur and with front shifting.
There aren’t that many to select from yet, but 1X road bikes are starting to become a thing. So I thought I’d try to get ahead of the trend and look at a couple of models to share how the 1X drivetrains I could find now compare to the traditional 2X drivetrains on the similar model from the same company.
For this discussion talking about drivetrains, we’re going to focus on the gearing on the bicycle (not the specific components). Because it’s the gearing that determines if a cyclist has the right range of gears to ride the terrain they choose to cover. What’s right for one rider might not be right for another because people have different preferences in how they ride and pedal and different fitness and ability levels, too.
I’ll also add some thoughts on how to decide if a 1X drivetrain could work for you and quash a few myths about 2X drivetrains that you may hear when shopping for a new road bike (or even a gravel bike).
Your take on drivetrain gearing choices is as valuable as mine. So, after reading this, please share your advice and tips on what you use and would recommend to other readers in the comments below.
Two 2026 1X road bikes from major bike companies
I picked two 1X 2026 bikes, one from Trek and one from Cervelo. I was looking for similar drivetrains not similar models of bikes so the price points vary and they fall under different categories. But, there are more 1X bikes to choose from by these companies if you’re interested and you can find them online to compare different models in the same bike category and specifications level.
The bikes I chose are a Cervelo road racing model and a Trek endurance bike (these have a more upright position than a road racing design). Since there’s usually an option to buy the 2X model of the same bike and the price might even be identical, we’ll look at the gearing on those, too.
That way you can see the gearing difference on the 1X versus the 2X model because that’s the key difference between the bikes. [NOTE that for the Trek bikes comparison, I could only find a similar 2X model at a lower model level but the gearing should be the same.]
Under each bike is the gearing chart. The chainrings are on top and the cassette cogs are on the left side. The numbers in the middle are the gear inch numbers. The lower the number the easier the gear is to pedal and the higher, the harder. Looking at the charts you can tell which bikes have the lowest and highest gearing and you can also compare the numbers to get an idea of how much the gear inches increase or decrease with each shift down or up the cassette.
Ideally, when you’re at speed you want closer spacing between shifts so that you can fine tune your effort. When the going is tougher, such as on climbs, larger spacing between shifts makes sense because you’re slowing down and need a much easier gear, not just a little easier.
1X versus 2X shifting
With a 1X bike, the gearing and shifting is simple because there’s only 1 chainring. To shift, you move the chain up or down the cassette, that’s all there is to it. Both the 1X bikes here have the same 13-speed cassette. That’s because with only a single chainring, that extra cog allows a wider gear range, or it could be used to narrow the gap between one of the jumps on the cassette. In the case of the 10-46 13-speed cassettes on the bikes here, I believe SRAM’s goal was to ensure you have a low enough climbing gear and tighter jumps.
With a 2X bike, the gearing and shifting is complicated because there are 2 chainrings and a front derailleur. To shift you move the chain up and down the cassette, plus you have the option of changing between the front chainrings too.
The advantage of having 2 chainrings and the ability to shift between them is that those front shifts make a significant change in the ease or difficulty of pedaling, whereas with 1X gearing to make the same amount of change in the gear, you would need to make multiple shifts.
Whether that 2X advantage matters depends entirely on how you ride. Mountain bikers have pretty much gone completely to 1X because it’s a simple system that works on all types of off-road terrain. The necessity to shift a lot to change gearing significantly isn’t considered a drawback because of the slower speeds and typically steeper and more technical terrain.
For road, gravel, touring, bike packing – and especially racing or competitive riders, 2Xs may be the better choice because they give you the ability to hit the best gear more quickly. And, always being in the right gear should provide a competitive edge and energy savings. For a racer or weekend warrior for example, with one front shift to a much higher or lower gear to launch an attack down or uphill you could open a race-winning gap while the 1X rider is still shifting.
How the gearing compares on our example bikes
I think what you can see from the gear charts is that the 1X gearing with the extra 13th cog makes it possible to get almost the same lowest and highest gears as what you get on the 2X bikes. Because Trek went with a 44-tooth chainring, their 1X offers a slightly lower lowest gear (25.8 to 26.25) while it loses about 11 inches on the highest end of the gear range (129.6 to 118.8).
Cervelo chose a 48 tooth chainring on their 1X, which matches the 48 large ring on their 2X so both have a highest gear of 129.6. And even with a smaller 10-33 versus the 10-36 cassette on the Trek, the 1X Cervelo’s 10-46 cassette gives a tiny edge to the 1X on the lowest end with a 28.2 versus a 28.6 on the 2X.
Considering how closely the gearing matches, deciding which is right for you really comes down to personal preference. It’s unlikely you’ll feel like you’re missing something unless you’re used to 2X shifting, in which case, I think if you shifted your front derailleur regularly before, you will likely miss that option on a 1X. But only you can decide if it matters for how you ride or not.
The example bikes
1X MODEL: Trek Domane SL7 AXS 1X Gen 5 ($6499.99):
Gearing: 44-tooth chainring with 10-46 13-speed cassette
| Trek Domane 1X | 44 |
| 10 | 118.8 |
| 11 | 108 |
| 12 | 99 |
| 13 | 91.4 |
| 15 | 79.2 |
| 17 | 69.8 |
| 19 | 62.5 |
| 21 | 56.6 |
| 24 | 49.5 |
| 28 | 44.4 |
| 32 | 37 |
| 38 | 31.3 |
| 46 | 25.8 |
2X MODEL: Trek Domane SL6 AXS Gen 5 ($4199.99)
Gearing: 48/35 tooth chainrings with 10-36 12-speed cassette
| Trek Domane 2X | 35 | 48 |
| 10 | 94.5 | 129.6 |
| 11 | 85.9 | 117.8 |
| 12 | 78.7 | 108 |
| 13 | 72.7 | 99.7 |
| 15 | 63 | 86.4 |
| 17 | 55.6 | 76.2 |
| 19 | 49.7 | 68.2 |
| 21 | 45 | 61.7 |
| 24 | 39.4 | 54 |
| 28 | 33.75 | 46.2 |
| 32 | 29.5 | 40.5 |
| 36 | 26.25 | 36 |
1X MODEL: Cervelo Soloist AXS 1 ($8500)
Gearing: 48-tooth chainring with 10-46 13-speed cassette
| Cervelo Soloist 1X | 48 |
| 10 | 129.6 |
| 11 | 117.8 |
| 12 | 108 |
| 13 | 99.7 |
| 15 | 86.4 |
| 17 | 76.2 |
| 19 | 68.2 |
| 21 | 61.7 |
| 24 | 54 |
| 28 | 46.2 |
| 32 | 40.5 |
| 38 | 34 |
| 46 | 28.2 |
2X MODEL: Cervelo Soloist AXS ($8500)
Gearing: 48/35 tooth chainrings with 10-33 12-speed cassette
| Cervelo Soloist 2X | 35 | 48 |
| 10 | 94.5 | 129.6 |
| 11 | 85.9 | 117.8 |
| 12 | 78.7 | 108 |
| 13 | 72.7 | 99.7 |
| 14 | 67.5 | 92.6 |
| 15 | 63 | 86.4 |
| 17 | 55.6 | 76.2 |
| 19 | 49.7 | 68.2 |
| 21 | 45 | 61.7 |
| 24 | 39.4 | 54 |
| 28 | 33.75 | 46.2 |
| 33 | 28.6 | 39.2 |
Addressing some common myths about 2X drivetrains
The popularity of 1X drivetrains has resulted in some negativity towards 2Xs in various publications and social media, etc. Here’s my take on some of the myths you might read or hear when shopping for bikes.
Myth: Front derailleurs throw chains
Fact: There are 2 reasons that this can happen and neither is the fault of the front derailleur. Derailleurs that throw chains either were not adjusted correctly or may have gotten bent somehow.
More: You could argue that since front derailleurs need to be properly adjusted to work right and can get bent, that’s enough reason to do away with them. But people who appreciate front shifting would argue that if you keep your bike properly adjusted you’ll never have a problem.
Myth: By getting rid of the front derailleur, second chainring, cable/housing and shifter you save a lot of weight
Fact: If the 1X matches the gearing range on the 2X, it’s because of an oversize cassette, which requires an oversize derailleur to shift it, and it might need a longer chain too. All these add weight so the bike might not be much lighter at all.
More: With wireless electronic drivetrains there are no cables or wires to add weight.
Myth: 1X drivetrains are more efficient than 2X drivetrains
Fact: It’s almost too close to call but because there are greater crossover angles on a 1X and you spend more time in them, the 2X is actually slightly more efficient – but nothing you’d probably notice.
More: Some electronic 2X bikes won’t even let you use the crossover gears.
Your turn
If you’re hunting for the perfect new road bike it would be interesting and helpful to learn if you’re considering going to a 1X and why. If you are a gearing aficionado with advice on how to choose what’s best, feel free to weigh in too. Thanks!
Jim Langley is RBR’s Technical Editor. A pro mechanic & cycling writer for more than 40 years, he’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Tune in to Jim’s popular YouTube channel for wheel building & bike repair how-to’s. Jim’s also known for his cycling streak that ended in February 2022 with a total of 10,269 consecutive daily rides (28 years, 1 month and 11 days of never missing a ride). Click to read Jim’s full bio.
get a new bike to save one derailleur and chain ring
i would need a better reason than that
i haven;t even gone to carbon yet – or steel for that matter
or gravel
all aluminum!
i guess i am not the target audience for a new bike every year
i shouldn;t even be commenting
answer:”no”
If we had the wonderful Sun Tour sprocket boards in most shops, it would be different. My legs hate large gear jumps, and with 2X the cogs seem to be closer together. My Campagnolo mechanical is so quick and reliable, I’ve never seen the need for either 1x or electronic.
‘gearing’ = development per crank rotation is given in ‘inches’.. omg… at least add a column in metric units.
and I’d like to point out this excellent graph showing ‘gearing’ and allowing comparisons :
https://ritzelrechner.de/
greetings from Germany
Herbert
I purchased a new cervelo that came with a 1x.
Unfortunately I have Thorasic outlet syndrome and absolutely could not deal with how many shifts it took to get up a hill. I have found that the 2x works better for my condition.
Also if you have arthritis in your hands a 1x is difficult.
Just my perspective.
I started on a 3x, moved to a 2x, and then spent a European bike tour riding a 1x. While I got used to the 1x, I constantly found myself wishing for that “extra half gear. I still prefer a 2x over a 1x.
Given a choice, I chose 2x for the ability to sustain the cadence I’m comfortable at. Have 2, 2x bikes and 1, 1x.
I’m not a racer, nor am I fast by the standards of the road bike community. I’m a persistent distance cyclist who enjoys being on a bike for long periods of time.
I’ve had a 2x drive train forever. My next bike (coming soon!) will have a 1x. I’ve tried multiple models at local bike shops and have determined that, for me, the front shifting isn’t necessary. I’ll probably spend a lot of time in the middle of the cassette where the jumps are closer together, and I’m more concerned about the low end than the high.
A few years ago I converted my wife’s triathlon bike from 2x to 1x. I changed the cassette from an 11-32 to an
11-46. The bike originally had a 50 tooth big ring on the 2x crankset. I still maintained a 50 tooth chainring on the 1x setup. So she ended up with the same high gear as before and got a slightly lower low gear (original 2x had a 36 tooth small ring). She loved the new setup and was happy to not have to shift a front derailleur anymore.
I ride a fair bit of gravel, not much road. I’m on SRAM AXS 12-speed and recently moved from a 2x setup (46-30 in the front, 11-34 in the back) to a 1x setup (44 in the front, 10-51 in the back). The gearing range is slightly wider with the 1x setup (ratios of 0.86-4.40) vs. the 2x setup (ratios of 0.88-4.18).
I love the change, with the following caveats:
1. When I’m racing gravel, I’m really just riding hard, not optimizing the way I might in a crit
2. I don’t seem to be affected by bigger jumps
3. My experience with SRAM front derailleurs wasn’t great–it got better going from 11-speed to 12-speed, but it still threw the chain off the outside of the big ring on occasion. I don’t doubt that it’s possible to set this derailleur up to avoid this, but it’s a super-finicky setup that several shops weren’t able to get right.
I’m still running a 3x drivetrain on my bikes, so no…. However, I do see the advantage of a 1x drivetrain. Front derailleurs have to move the chain on the tension side, while rear derailleurs move the chain on the non-tension side, therefore rear derailleurs change gears more consistently while under load. That’s the big thing. Changing gears while applying heavy torque is more reliable at the rear.
I appreciate the usual thoroughness here, but think we missed the forest for the trees: I don’t think any comparison between two bikes / two drivetrains was/is necessary. With the degree of competition and diversity in the bike industry these days, I expect one can get (or build) any range of gearing in either mode (1 or 2 chainrings) on most any bike. The raw fact is a 1×13 provides 13 gears; a 2×13 provides 26 gears = do I want a higher number of options to dial into my effort relative to the terrain and circumstances, or not? A one-by forfeits more incremental shifts in favor of sometimes not having to shift the front derailleur (probably under difficult or competitive circumstances.) So once again, “the best” is defined not by the equipment, but the rider’s preference and use. // I also see that the “myth” of lighter weight for 1x vs 2x is noted, but really expected an actual weight comparison to be accomplished to confirm it is a myth = that would have been a thorough comparison (albeit tedious!)
Both of my road bikes are 2X. My hybrid is 1X. My main complaint about the 1X setup is that, as you say above, there are greater crossover angles on the 1X so the chain is perfectly aligned between front and rear less often, and I notice a bit more noise from the chain during pedaling the hybrid bike when it’s in one of the largest or smallest cogs versus the other two.
Cyclists sure are a nerdy bunch that over analyze the specs; as are many who are “into” a particular activity. I gave up on the spec’s and just want to ride my bike. With that I went the 1X route way back in 2019 with a Salsa Warbird 650B with SRAM Force 1 42×10-42 11 spd. I bought it with 650B’s for gravel and soon added a pair of 700c Spynergy GX wheels for the road. Every year I typically put the road wheels on it for the summer when it is too hot for the wooded dirt roads, and then flip back when it cools off. I’m in the deep south so we can ride year round. I’m not a racer and don’t fret about the clunky shifts that go up/down multiple cassette teeth. It will climb a tree if I’ll pedal it up. Top end is fine, because do I really need to pedal over 33 MPH? To me it is a perfect bike, way ahead of its time.
I’ve gone to 1x and never going back on all of my bikes: mountain , gravel, and road. I like the simplicity and the elimination of the front derailleur. it also allows me to use an oval front chainring, which is kind to my old knees. On my Cervelo road bike I have a 10-44 cassette with a SRAM Force AXS XPLR rear derailleur and 46 tooth oval chainring. On my gravel bike I have the same cassette and derailleur, but a slightly smaller 44T chainring. No problems climbing pretty steep hills in the St George Utah area. Only downside is that I can’t peddle down steep hills (I spin out) above 40mph, but that’s fast enough for me anyway.
On a previous road bike, a Trek Emonda, my experience with the SRAM ETAP front derailleur was terrible. it constantly threw the chain off both the inside and outside, no matter how it was adjusted, about once every few hundred miles. So glad to get rid of that hassle by going to a 1x.
And when I occasionally go back and ride my old Trek Domane with a Shimano Ultegra 2x setup which works great and never throws the chain, I still think the setup is clunky and overly complicated compared with the 1x.
As for being able to quickly change gears, the electronic shifting makes up for the smaller step size between the gears. Just hold the shift button and it “machine guns shifts” through a bunch of gears with no effort in very little time.
My new bike is 1X. I would never consider going back. Riding during the last 50 years, I’ve had 3X and mostly 2X and I don’t miss them at all.
Living in the Pacific NW, we do have some climbing, for sure.
Last time I rode, yesterday in fact, a friend with 2X had his chain come off a front chainring and wedge between his two chainrings. Not a problem for me anymore.
I would like to know some honest information on maintenance expense. I’ve seen online discussion saying the single chain ring and the cassette wear out much faster and chain life is less due to the friction of greater angles of high and low gears expericed with 1 chain ring. Is there any real evidence of this?
I have 6000 miles on my first chainring, cassette, and chain, with no issues on my Cervelo Caledonia with a 1x setup as described in my post. I weigh 150 lbs and rarely exceed 500W of power, if that matters. The electronic shifting of the SRAM Force derailleur may be smoother than a manual shifter with cables, and less likely to be between gears, so perhaps that helps? I have not measured the chain for wear. I do wipe off and lube my chain at least once a week.
I’m sharing a comment that came in to the RBR inbox from Phil. He says:
“I Bought my Specialized Turbo Creo back in 2021. It came with 1X chainring and the typical “pie plate” 10-52 cassette. The jumps on the cassette were too much so I wound up having to replace it with an 11-33 road cassette. That was expensive since the original wheels came with mtb hub body which would not fit the new cassette. So do your homework before you buy a 1X.”
I have a 2x road bike with mechanical ultegra and a 1x gravel bike (with a 2nd set of wheels for road) with Campagnolo Ekar. I lose 1 gear vs the 2x, the 50×11 equivalent that I never used unless going downhill. Since I now live in FLatland USA, I don’t miss the 2x as I have no need for abrupt changes in gearing. If I were still up north, I would prefer the 2x when I turn a corner and suddenly find a wall looming.
I think that the other thing to mention with Shimano Ultegra 2x 12 speed, is that it can be configured to change itself by gear ratio taking the decision of front shifting out of the riders hands (head).
I have 2x on my steel road bike (11/36 and 50/36), and on my steel tour bike (11/38 and 46/29). Road bike has Ultegra mechanical, and I wouldn’t have anything else. Shifts like butter, great spacing. Tour bike has bigger range and middle-of-the-road cost Sword, shifts are not as smooth, but on a tour bike who cares? No cross chaining happening on either. Why would you add that noise and wear on the chain??
With a 3x steel bike (Waterford) I could climb Independence Pass, do the Tuesday Nite Crit, TimeTrial, and Tour. Never road a bike with to many gears.
What good is a 117.8 or worse yet 129.6 gear?! Get your cadence over 30!
I am an older rider (71 YO) and purchased a custom road bike with SRAM 1X a couple of years ago. I used a smaller chain ring providing an easier ratio for climbing, which for me is perfect. I used to ride 2X, but this just makes life easier in my circumstance. I live and ride almost exclusively in the mountains of Colorado. My home is at 8700 feet and I ride typically up to 10,000 or 11,000 feet. The downside is that I cannot pedal past 35 MPH, but that is okay with me, since I am usually going either up or down a mountain, and rarely want to go faster. Everyone’s situation is different, but in my case, the 1X is simpler and can provide that “granny gear” allowing me to maintain a good cadence with steeper climbs (7-14% grades) — perfect for an old guy.