1x vs 2x Drivetrains For Gravel Bikes | The ANSWER! (Is In Gear Ratios)

Despite the many benefits of a 1x drivetrain, it seems that most gravel cyclists who stick with the trusty 2x drivetrain are simply afraid of the increased jumps between gears. But... How big are those jumps exactly? Are they evenly spaced across the cassette? Will the bigger jumps actually affect your riding? To answer these questions, we have no choice to dive head first into the nerdiest of all bike-related topics... GEAR RATIOS.

In this video, we go down a gear ratio rabbit hole to investigate the exact nature of the differences between 1x and 2x systems using numerical software and data analysis. Geek out with me as we marvel at the pretty graphs and ponder the KEY DISCOVERIES that may ultimately influence your decision to go 1x or 2x on your gravel steed!

Be sure to subscribe before you nod off to what is essentially a lecture on gear ratios. I challenge you to stay awake through the end. This WILL be on the midterm!

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Chapters:
0:00 Introduction
2:21 Pros and Cons of 1x
4:53 Who is 2x for?
6:55 Gear Ratio Analysis
8:29 Gear Redundancy on 2x
10:30 Key Discoveries - Jumps Between Gears
13:20 Summary

#ShowMeYourData
#GearRatiosAreTheAnswer
#BikeGeek

[jameskhoury]

You really went the extra mile here and it's appreciated. This has helped me loads to decide which way to go. Thanks

[JonathanDyer]

If you plan to just ride gravel, 1x sounds adequate. If you plan to mix road and gravel riding, 2x is more versatile. Thanks for the number crunching, cemented my decision.

[tipntrn]

Just found your site and it’s great! I’m also an engineer so I really appreciate the details.

I did similar analysis on 1x a couple of years ago. I changed my 3 mountain bikes to 1x. Best move ever. My girlfriend is a novice rider and struggled with 2x. She was always cross chaining and confused, especially in the woods. Now that she’s on 1x, she’s significantly improved because she doesn’t think about shifting. I strongly recommend 1x for anyone new to mt biking because of the simplicity.

Keep the good videos coming!

[azathell]

As Mr Quindazzi says the most important 1x problem is that you have to commit to a single chainring. If you go too extreme you will end up lacking. 34T will allow you to be almost in an MBT but you will not be able to race to much, and 46T might give you enough speed but you will have to be very strong to be able to climb a lot, even on a 10-36T cassette. The bottom line is that on gravel you might go 2x to have some "good for everything" bike or go 1x a commit a little more on what are you going to mostly do with your bike, road or climbs....

[cordurboy]

this was by far the most clear explanation i've seen on the advantages/disadvantages between 1x and 2x. helpful, thanks!

[gurgenmakaryan]

2x all the way, i have 1x mtb, 1x fatbike, 2x road bike, and recently purchased 2x gravel bike, and I'm convinced in a good choice. 1x drivetrain isn't good enough on the tarmac, if the relief is flat and hills, you have to play or shift several cogs to be ok, but on the 2x you just switch from big chairing to the small, and thats all. Another big issu with 1x is the high speed on the tarmac, 40x11 isn't enough for moderate cadence
And of course, any cycliste must have some knowledge how 2x chainring works and how to adjust front derailleur, i mean trim position or fully engaged to avoid the chain and derailleur contact

[MrDvdelft]

No-one want to talk about increased chain wear on the 1x system as you will ride with a much more angled chain pull when in the lighter(est) gears. And this adds noise too. Not a biggy, but worth a thought. Apart from that, for beginners and non-wrenchers, 1x will serve you well everywhere

[aaronbehindbars]

Great video! I had this very debate when I was deciding which gravel bike to buy. I have increasingly favored 1x drivetrains on my bikes over the last few years. I find 1x stems better suited for off-road riding or casual street riding. The larger jumps are more noticeable and less desirable when you are going faster and trying to find that optimal cadence as you mentioned in your video. It looks like Shimano tried to eliminate that as much as possible and, like you, I am second guessing my decision to go 2x on my gravel bike.

I definitely should have studied gear ratios a bit more to better understand how my ride would have been impacted by the ratio gaps. My logic was oversimplified in that I decided that 1x11 would not yield appropriate ratio gaps and that I would need at least a 1x12 to achieve a more appropriate progression of ratios. Perhaps that is somewhat accurate, but after looking at how Shimano does it, I think I would have been just fine because regardless of whether you go 11-40, 11-42, or 11-46, all three have the same progression of 11-13-15-17-19-21-24.

Then, along comes Campy with their new Ekar 1x13 gravel groupset. Have you seen it? They offer 3 different cassette options:







Looks like they are taking what Shimano does to the next level with packing the top end of the cassette with very tightly spaced gears.

Had I gone with a 1x gravel bike, it more than likely would have been equipped with SRAM Apex 1:



They start ramping up the progression one cog earlier than Shimano with a larger jump from 19-22.

My Specialized Diverge has a Shimano 11-34 configured as such:



The 48T big ring on my bikes does have me favoring the 17-19-21-23-27 cogs most which are all 2 tooth ratio gaps. Had I gone 1x SRAM with a 42T ring, I would be favoring the 15-17-19-22-25 cogs. My ratios would be very close to the same with the 1x setup except for when I was on the 22 and 25 where the gaps spread just a tad. Not likely a big deal.

Sorry this is so long of a comment, but one last thing. After getting my Diverge, I ended up building a super budget gravel bike that I intend to actually ride on the local mountain bike trails. I have it setup with 650B x 47 tubeless tires and a 1x8, 38T ring with an 11-40 cassette. Those are some big jumps (11-13-16-20-24-28-34-40)! The little bit I have ridden it on trails does seem to validate my initial impression that 1x is better suited for slower riding. It is insanely fun and I can't wait to try it out with the recently installed dropper post!

Thanks for hopefully reading this and I look forward to more content like this if you decide to make it.

[DrummClem]

I recently decided to refurbish my old bike and think about modernizing the drivetrain.
I had my last bike 25 years ago so it's been a while and so much has changed since.
Nice to see this video. Saved me some time and an Excel spreadsheet;)

[ianraybetron]

Just went back to a 2x system on my second mtb...first to address the chainline issues of the 1x system. Then the gear ratios. Good that I stayed with my 2x on my first mtb.

[mycyclecoachGA]

BEST description on the topic....and CLEARLY showed the side-by-side comparison and where the literal differences are.

[carterliu]

Best gear ratio video ever. Change chain ring will jump a few gears, this can be annoying at times. Yes, experience with your bike will minimise the pause effect but still not as intuitive compared to 1 by - "not quite the gear I wanted, try the next one". For people new to cycling, this ease of use characteristic of 1 by is a bonus.

[TheRoadrunner]

As someone who has/had 1x, 2x and 3x both in MTB and road bikes, allow me to share my personal opinion on the matter:
1x is way cooler looking and offers a clean cockpit. But the range will be more "specialized" for lack of a better term; meaning you either choose high range for speed or low range for climbing, but not both in the same ride (depending on the size of the installed single chainring in the front)
2x and 3x might look a bit uglier yes, but in terms of functionality, range, as well as jumps between gears, there is no beating them!
That's why my adventure machine (a Hardtail) is still a 3x10 to this day. I mostly only use 2 of the rings upfront, but just having the option to switch to the tiny third ring in the front has saved my ass many times where a hill is too steep. Meanwhile the largest chainring (40 tooth) allow me to go downhill to almost 55 Kmh before I start spinning out (I don't like spinning fast, more of a grinder, so my cadence is probably lower than average).
In short. I don't like 1x as much as a 2x or a 3x, regardless of the kind of bike, even Mountainbikes, which is why I got rid of my 1x SRAM eagle XC bike and got a 2x instead.

[SushantYogi]

MTB person here and this video was hugely helpful for me as well. I was quite literally thinking about doing some Matlab coding myself to quantity the difference between 1x, 2x & 3x MTBs too so I'm glad I stumbled upon your video doing the exact same. Definitely worth geeking out to some gear ratios

[georgestamulis]

Finally a mathmatical geometric on the gearing of 1 by vs 2 by. I just ordered my Sram 1 by and have been searching the internet for fear that I may be missing the smaller gaps in the larger gears, and thankfuly you address the answer. I'll be fine! Great job!

[khaimapostol]

Started out on a 1x mountain bike and always felt like I didn't have enough top end speed. Went 2x (50/34) on my gravel bike with an 11-40 cassette and I finally found an almost perfect system for climbing up and sprinting on flats and descents.

[shanefrechette]

Thanks for the video and sharing your thought’s I went with 2x GRX 810 31/48 up front and XT 11/42 in the rear, for just about anywhere you want to go.

[teamvergs]

many thanks for this! for me 1x set up if you are doing bikepacking, recreational rides which is enough...2x if you gravel race and definitely road cycling..

[alexramirez]

Yup, I been a roadie for over 10 years. Just recently jumped to a gravel bike & hard tail MTB. Gear gaps are just insane, for a roadie...its taking time to get use to it

[SjaakSchulteis]

After I had my old mountainbike serviced, I noticed that while speeding up with the front on the smaller wheel, it didn't grab the chain and I almost died on a road, because I couldn't get my bike going. Ever since I used the big blade on the front and learnt to change only the back gear. Now I'm looking for a new bike and I want to buy a gravelbike as under the circumstances where I drive here in Thailand (rough and smooth roads, sand, and gravel on the road) I found a lot information about anything related to gravelbikes (and mountainbikes). And given the experience I had and your video, the choice is easy: I go for the 1x drivetrain. Last sunday I was in a shop which only had mountainbikes or racebikes, the seller was showing the 1x drivetrain bikes as the latest innovation. I thought it was ridiculous, but now I learnt that this is really what I want. Thanks for helping me decide!