Gravel Bike Set up: 1x or 2x

Equipment
1

Basically, my question is: can a (1x) 42t chain-ring, 11 x 40 set up keep me fast on the flats, and enough options on the hills?

Context: So I bought a Trek Boone 7 for cyclo-cross, and now I will be converting it to a gravel bike for some upcoming long gravel races. I have gotten use to the cyclo set up and absolutely love the 1x. It’s clean, lighter and simple. However, I will need to decide on a new ratio of gears to keep me fast on the flats, and gear options on climbs. Here is my current option:

(1) 42t chain-ring, 11 x 40

(2) 52/34 11 x 36

My goal is to be competitive, so I want to make sure I choose wisely. Any input is appreciated.

2

If you can swap the 52 to a 50 you’ll be fine assuming you have the power for steep climbs. I shift a lot and do not understand why anyone would want a 1x. Give me the options.

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3

I’m going to assume you meant to write 50/34. A 52-tooth chain ring is too large for gravel racing. Even for most road riding, you don’t need a 52.

Regarding gravel racing, have a look at this gear chart comparing the two: you will lose one gear at the bottom and two gears at the top. However, on 40 mm wide tires and a mere 90 rpm, you will still do 46 km/h and 51 km/h at 100 rpm. So a 42:11 should be fine even on quicker on-road rides. On gravel this should be plenty. That is, unless you like to grind gears.

The real question is IMHO the bottom end. Here, this really depends on the terrain. If you venture into “easy mountain bike territory”, you might need more than 1-to-1 gearing in case you encounter many sustained, steep climbs. If only short climbs are peppered in, you might be fine.

In any case, if you go 2x, then a 52/34 or 50/34 is going to be way too tall. A 46/30 (≠ 46/36!) will probably be a better choice. Although I doubt you’ll be using 46:11 very much on gravel, that’s essentially the same ratio as 50:12.

It seems that the gravel community is roughly divided in half whether to go 1x or 2x. My next road bike will be 1x, so you can guess what camp I am in. But it is largely a matter of preference these days. Some people have anxiety about always having another gear left or are very picky about their cadence, then surely 2x is the better option.

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4

I run a 46x10-42 on my Aspero gravel/road rig and love it. Occasionally I wish for tighter gearing if I am doing an outside workout on a hill climb and would prefer more control over my cadence, but I can’t imagine gravel racing on a 2x honestly. If your bike is going to see a lot of road duty I would get frustrated spinning out a 42x11 on big descents in the CO front range (I still spin out my 46x10) but have always found my 46x42 to be plenty for climbing around here all day.
An XD driver that gives you a 10t (or even 9t from e13) would give you tons of top end and 42x42 is more than enough to climb on.

5

What are you running at the moment on your (road) bike? I think comparing it to what you have is a good idea.

I run 42 - 11-42 on my gravel wheels and a 10-42 on my road wheels. The 10t cog really makes a difference on false flats/downhills when you want to keep pushing a bit - I wouldn’t say you need it for speed, for me, it’s rather to keep the pressure on the pedals and stay in a training zone on (straight) downhills. Personally, I like the simplicity of 1x. I know some people dislike the gear jumps. With a lot of rolling terrains and a lot of stop and go I quite often shift a few gears at a time - even on 1x… :upside_down_face:.

But coming back to your question: If it’s gravel races I doubt that you even need that 10t cog. At least to me it’s hard to imagine on gravel at 50km/h feeling the need to speed up instead of just aero tucking and trying to keep control :slight_smile:.

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6

Competitive at what types of events? It seems like these discussions always fall into the same pattern…

“1x is great, you should use it!”

and

“2x is great, you should use it!”

I would recommend you consider the specific needs of your events. For example, if you have an event with an extended paved road descent in the 3-7% range, you could lose the group if you don’t have a big enough gear. Anecdotally, I have seen this happen on gravel group rides & races, precisely because people see it as an opportunity to create separation from a group of riders. Trying to spin at 130+ rpm to go 60-70kph + when you are tired is rough. On the other hand, if you don’t have this scenario in your type of events, that big gear may be totally unnecessary.

Further into the details this is a tricky decision…it gets very expensive to switch groupsets and/or brands of these setups. As discussed in the other 1x12 thread, there aren’t really any options for 1x12 mechanical. SRAM AXS is nice, but very expensive. The new Campy Ekar 1x13 mechanical is interesting but might be hard to source. Shimano 2x11 GRX mechanical works well for me, others may have different opinions. 1x11 mech isn’t super appealing considering the other options out there, 2x11 GRX Di2 is another higher end choice as well.

Personally, my Aspero came with GRX 2x mechanical and I had planned to change it out. I’m still not super in love with the shape of the levers, but I can’t make a good case why I should change to anything that will be very much lighter/better performing/better gear range/etc. so I’m going to run with it for a while and spend money on more meaningful upgrades.

7

I’m chiming in without reading many of the replies below: With my experience, which isn’t DK, TransIowa, Midsouth type epics, but with a CX bike as only bike for a while, as a commuter for a long time, and as the only mid-tire width style of bike I’ve ever ridden… 2x is imminently more versatile. Its not about the top end or the bottom end, or range at all: its about fine tuning your comfortable cadence while you’re on some rollers, into a head wind, or descending with a tailwind. When you’re wheel sucking faster guys, the difference between a natural cadence and grabbing up and down for gears can mean hanging on or falling off. (I still managed to fall off plenty of times, but wouldn’t want it to be worse.)

I won’t pile on specific manufacturers because people get offended, but it seems like companies, generically, are going 1x to hit an OEM price point, and selling it as an improvement. I weigh 189 lbs (85.79kg) on a fit day, why would I give two hoots about an extra 89g of an FD? I could leave my phone at home and save more than the whole difference between a 1x and 2x system.

I started with a 48/39 front (9spd-12-26? rear), and actually liked the spacing up front. It was small enough I could change the front more often than I would have been able to otherwise. That bike is now 46/36 x 11/28 (10spd) and I absolutely could have used a lower end, but that “problem” would easily be solved with a modern cassette (32, 34, 36 tooth). It did improve going from a 39 to a 36 front inner.

Now, my primary cx/commuter is 1x… but only because I moved from my previous rolling terrain to FlatLandia where I can ride 40 miles and have my Garmin register <200 ft of elevation gain. BUT, when the current left shifter fails, or the RD breaks, or, yeah, it will go 2x whenever there’s a part in that system to be replaced.

And I actually ran into this, after a crash in a CX race - my right shifter failed. I couldn’t downshift (go up the cassette to a lighter gear), but my left/front shifter still worked, so I managed to finish the race with a two speed. I think that variability was worth more on that day than the number of grams that could have been saved.

All things considered, go 2x if you’ve got the chance. Now, I’ll go read the rest of the responses.

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Whether it’s gravel or road, it always boils down to the same thing. With 1x setups you gain in simplicity and reliability (marginally you save weight and cost), but you have to compromise on either range or gaps. Whether or not that compromise is worth it is totally dependent on you as a rider and the type of riding you do. A stronger rider in an area without extended or very steep climbs probably could make it work very well. But others might well ask, ‘Why bother?’

I loathe front derailleurs as a general rule, but still haven’t gone down the 1x route on a conventional road bike (and I ride gravel so occasionally it’s irrelevant).

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Something not yet mentioned yet is what you’re getting for ‘gear inches’, where one more tooth on a front ring only equates to approx 1 inch difference, versus one tooth on rear cog equating to approx 10 inch difference.
Something to consider!

10

I entertained 1X for my gravel bike but ultimately decided on a 2X. It was the right choice for me as the majority of my riding ended up being on pavement anyway. Any of the gravel races on my radar would be better with a 2X as they all have some paved sections and very steep climbs.

I did see someone run a 1X for an TT style hill climb over the summer, sub 10 minute climbs, nothing too steep. That made sense but it’s super specialized.

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Hmm… so how does that impact a 1x vs 2x setup practically? Genuine q.

I hope what follows doesn’t derail the thread and if it’s deemed inappropriate I apologise, but hopefully this sheds light on the wider issue.

I’ve spent quite a lot of time playing around with the idea of a 1x for road, and what I have mainly looked at is ratios and data from my SRAM AXS app.

I have a 48/35 and a 10-33 setup. I’m a fairly strong rider (just under 4w/kg) but by no means genuinely quick. I live on the outskirts of the Chilterns in the UK, so you get lots of short, sharp inclines but very few sustained (>7-8 min) climbs. It’s puncheur territory.

The app suggests I pretty much never use 48-10, and tbh I’m not in 48-11 for more than a few minutes total in a 3hr ride. That tells me that honestly a 4.4 or so is enough for me.

At the bottom, there is only 1 hill within a 30 mile radius that really compels me to use 35/33, and I have got up it (slowly) on a 36/30 before now. Though lower is welcome in a few other places if/when I’m tired, I can get by with 35/28 (1.25), though I’d like some insurance. So that tells me that 1.2 is enough at the bottom.

With that in mind, a 44 front ring and a 10-36 cassette (SRAM) or a 40 and a 9-36 (Ekar) seem like sensible options for me. Have I missed something with gear inches?

Thanks in advance.

12

Yeah happy to expand upon that! I’ll use that gear ratio example @fornes1 mentions above:

1x Setup of 46 x 10-42
High: 31.77 inches
Low: 133.4 inches

2x Setup of 50/ 34 x 11-36
High: 27.38 inches
Low: 131.81 inches

:point_up_2: This really speaks to how a lot of folks feel that you’re getting a super comparable gear ratio by creating a bigger disparity in rear cassette high/low gears. Your easiest gear is easier for 2x, but you have a ‘bigger’ or harder gear available with the 1x! Pretty interesting.

That can of course change depending upon the chainrings / cassette you use though, for example, a 1x with an 11x36 kind of negates that comparability.

It’ll come down to your preference ultimately, but just neat to see how much more the rear cog effects gear inches versus front chainring. I know I prefer 1x!

EDIT: forgot to address what you have/are considering:

If now you’re running:
(2x) 48/35 x 10-33
High: 30.75
Low: 139.2

And youre considering:
(1x) 44 x 10-36
High: 35.44
Low: 127.6

Your easiest gear is more difficult than before, and your toughest is not as difficult. Maybe that 44 x 10-42 example is the ticket? OR sticking with 2x. Totally depends on how you like to ride and which gears you wish you had more of!

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This is where sram is awesome, you can tell how much time your in each gear and how switching to a different platform will impact you as you can see what gear you use more. Would love that data on my shimano

14

I have a 1x with a 42t front. One thing I’ll throw into the conversation is if you use this bike for TR, a 10-42 rear isn’t optimal. The gearing jumps between gears are too large for some interval work imho

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If you have Di2 and get the D-fly unit, that is able to connect with the SRAM app, and you can get it. I don’t know if you can customise the cassette configuration in the app, but it can still provide you actionable data.

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I’ve gone full circle with my gravel bike.

My first dedicated gravel build was quite some time ago, so I cobbled up a mix of road compact front 50/34 with SRAM XX 11-32 cassette. In order to run this cassette, I needed to run MTB rear derailleur, so I ran the SRAM XX derailleur.

The old Ridley X-Fire wasn’t the most supple or stable gravel racer, so once the Cannondale Slate came out, I decided to venture to the simplified world of 1x drivetrains. Having spent much time cleaning mud out of my 2x drivetrain (and cantilever brakes!!) at a now-renamed major gravel race in the Midwest, the simplicity was rather appealing. I rode/raced the Slate happily for a few years with its 44T/10-42 gear combo. I had almost all the range of the old 2x setup, but no front derailleur to mess with. Not being Ted King, only on fast fire road descents I would at time find myself spinning out the 44-10. However, the large gaps in gearing were at times frustrating late into events. Once you’ve been on your bike 10 hours or more, the littlest things can become big things.

A year ago, as I was planning for the season of 2020 (huh, what happened to that?), I decided that I wanted to go back to 2x. I selected the SuperX AXS Force Etap for this purpose. It came with a 46/33 crankset and a 10-33 cassette. The season didn’t play out as hoped, but I’ve had enough time on the bike that I can say I’m very happy with my choice. The extra complexity and weight of the 2x drivetrain (AXS isn’t exactly weightweenie to start with) is forgotten quickly as can always find happy cadences to work with, even when fatigue starts rearing its’ ugly head.

Next project will be to see if the new 10-36 AXS cassette will work without buying a new longer cage derailleur. SRAM says one needs to replace the derailleur, but there are reports of this not necessarily being the case. With the 46/33 chainrings, that cassette would be a welcome item for long sustained climbs in the mountains.

Bottom line, I think the 1x is fabulous on mountain bikes or cyclocross, but I wouldn’t do another gravel/road bike with 1x.

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17

I’m definitely swapping over to 2x for next season…I don’t really need it here in pancake-flat Chicago, but I have The Rift on my tenative schedule for next year…and really I could have used a 2x at DK in 2019 as a 40x36 was a bit of a grind on some climbs (even through they were short).

Going 2x gets you a wider range with smaller steps in between without having to resort to Frankenbike set-ups.

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My road next bike will have a 42-tooth chainring and a 10-36 cassette (Force eTap). I’d go for Campag if I liked their shifter lever ergonomics, but alas, I really don’t. I’m in a similar power-to-weight class as you are, and I agree, I don’t really use my 50:11 or 52:11 on my current bike. There are only a few rollers where I can safely use such tall gears. Even when zipping along at 50 km/h I’m in 50:13 or at most 50:12. Since we do have proper mountains, I still do need a proper low gear. A 42:36 = 1.17 is a tad taller than 34:30 = 1.13.

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https://www.reactiongifs.us/wp-content/uploads/2015/06/blaspheme_blues_brothers.gif(image larger than 4 MB)

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I went a double on my gravel bike, I just didn’t like the big jumps in the cassettes needed to run a single ring. I’ve also never really had a problem with front derailleurs such that I see them as a burden. I only ditched the front mech on my mountain bike to make more room on the bars for my dropper lever, not because it wasn’t useful.