Introduction:
mountain bike 1X drivetrain guide

mountain bike 1X drivetrain guide

In this article I aim to give you some tips and product suggestions on how to build up a single front chainring 1X drivetrain (1×9, 1×10, 1×11) for your mountain bike. I hope to make this a simple journey by letting you know my personal selections for the best options and letting you decide which brands and parts would work best for you.

When it comes to mountain bikes these days it seems like everything is getting more complicated and technical. Have you seen the dizzying array of bottom bracket standards and headset choices available? How about trying to dial in fork and shock tuning?

While these new complications are often for the better, because they make our parts stronger, more adaptable, and often lighter weight, they can bog us down mentally and take some of the simple fun out of riding. This is where 1X or single chainring drivetrains come in. The concept isn’t totally new, but these days there are quite a few modern products that make running a single ring drivetrain a lot more easy to set up and ride efficiently.


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Why would I want to run a 1X Drivetrain?
  • Lightweight – By getting rid of the front shifter, front derailleur, all of the cabling, and 1 or 2 chainrings you’re going to take quite a bit of weight off your bike. As a bonus this also declutters your handlebar a bit.
  • Simple – Now you can focus on riding and only worrying about shifting your rear derailleur. You no longer have to fear bad chainring combinations and deciding which front ring is going to work best for the next section. This mental stress can get a bit fatiguing and now you can just focus on attacking the trail.
  • Lower maintenance – Without the front derailleur and shifter this a few less components to have to adjust and maintain. You also get to save a bit of money by only replacing a single ring vs. a whole set when they wear out.
  • More ground clearance – When setting up a 1X drivetrain you usually use a much smaller front chainring than a typical multi-chainring setup. This offers greater ground clearance allowing you to clear obstacles more easily.
  • Quiet drivetrain – With the advent of clutch type rear derailleurs (SRAM Type 2 and Shimano Shadow Plus) chainslap is heavily minimized because the derailleur does not move as freely. The chain is also shorter and has more tension in a 1X drivetrain, which also helps on noise with riding over rough terrain.
What cassette should I run?

Since you are only running a single front ring you’ll want to have the most range you can get in your cassette. Typical cassettes that a lot of riders use are 11/12T-34/36T. SRAM and Shimano both offer a wide range of modern cassettes in 9 to 11 speed models.

Suggested 9-Speed Cassettes

Shimano HG61-9 12-36T cassette

Shimano HG61-9 12-36T cassette

  • Shimano XTR M970 | 11-34T or 12-34T
  • Shimano XT M770 | 11-32T or 11-34T
  • Shimano HG61 | 12-36T
  • SRAM PG 990 | 11-32T or 11-34T
  • SRAM PG 980 | 11-32T or 11-34T
  • SRAM PG 970 | 11-32T or 11-34T

shopping iconIf you’re looking to buy a 9-speed cassette online I suggest checking out Jenson USA for the best selection and prices.


Suggested 10-Speed Cassettes

SRAM XG-1080 cassette

SRAM XG 1080 cassette

  • Shimano XTR M980 | 11-34T or 11-36T
  • Shimano XT M771 | 11-34T or 11-36T
  • Shimano SLX HG81 | 11-34T or 11-36T
  • SRAM XG 1080 | 11-36T
  • SRAM PG 1070 | 11-36T or 12-36T

shopping iconIf you’re looking to buy a 10-speed cassette online I suggest checking out Jenson USA for the best selection and prices.


Suggested 11-Speed Cassette

SRAM XX1 XG 1099 cassette

SRAM XX1 XG 1199 cassette

  • SRAM XX1 XG 1199 | 10-42T

shopping iconIf you’re looking to buy a 11-speed cassette online I suggest checking out Jenson USA for the best selection and prices.


What size and type of rear derailleur do I need?

When looking at rear derailleurs you’re going to more than likely need a medium cage derailleur (Shimano calls this GS). Since you’re not shifting front chainrings, chain growth is not as much of an issue allowing you to run shorter chain lengths as well as using medium or even short cage derailleurs. Shorter derailleurs also have the side benefit of being more out of the way from rocks and other obstacles that can damage long cage derailleurs more easily.

I would suggest looking at getting a clutch type derailleur if you can for a 1X drivetrain setup. These new style derailleurs called Type 2 by SRAM and Shadow Plus by Shimano don’t have the free play in the cage like older derailleurs. They keep tension on the chain much better, making it much harder to drop a chain. Since these derailleurs don’t shake up and down they don’t make hardly any noise, keeping the drivetrain quiet over rough conditions.

Suggested 9-Speed Derailleurs

SRAM X0 9 speed rear derailleur

SRAM X0 9 speed rear derailleur

  • Shimano XTR M972
  • Shimano XT M772
  • Shimano SLX M662
  • SRAM X.0
  • SRAM X.9

shopping iconIf you’re looking to buy a 9-speed rear derailleur online I suggest checking out Jenson USA for the best selection and prices.


Suggested 10-Speed Derailleurs

Shimano XTR M986 Shadow Plus rear derailleur

Shimano XTR M986 Shadow Plus rear derailleur

  • Shimano XTR M986 Shadow Plus
  • Shimano XTR M981
  • Shimano XTR M980
  • Shimano XT M786 Shadow Plus
  • Shimano XT M781
  • Shimano XT M780
  • Shimano SLX M675 Shadow Plus
  • Shimano SLX M670
  • Shimano SLX M663
  • Shimano Zee M640 Shadow Plus
  • SRAM X.0
  • SRAM X.0 Type 2
  • SRAM X.9
  • SRAM X.9 Type 2

shopping iconIf you’re looking to buy a 10-speed rear derailleur online I suggest checking out Jenson USA for the best selection and prices.


Suggested 11-Speed Derailleurs

SRAM XX1 rear derailleur

SRAM XX1 rear derailleur

  • SRAM XX1

shopping iconIf you’re looking to buy a 11-speed rear derailleur online I suggest checking out Jenson USA for the best selection and prices.


What size and type of chainring should I use?

Chainring technology and sizes have changed a lot with the advent of 1X drivetrains. Most riders are using single ring specific chainrings because they are often built more beefy and have different tooth profiles that are better at retaining a chain. The most advanced chainrings available are designed to be ran without a chainguide using a clutch type derailleur.

The critical piece of hardware in this decision will be your cranks. You’ll need to know your crankset BCD (Bolt Circle Diameter) by measuring it yourself or checking the specs with the manufacturer. If your cranks are a standard 104 BCD then you’ll have the most options available for chainrings. If you have SRAM cranks that have the splined interface (eg X9/X0/AKA/OE S1400/ OE S2210), or XTR M985 cranks with a 88 BCD you’ll have some other options.

Once you’ve ironed out the type of chainring that fits your cranks you’ll need to decide on a tooth count. Most riders feel something in the range of 30-32T is a good size for general trail riding. You can, however, find smaller sizes down in the 20′s that work with some cranksets. If you don’t do a lot of climbing a 32-38T chainring may be what you’re after.

Suggested chainrings:

  • Wolf Tooth Components – These rings are made in the USA and designed to be used without a chainguide with a Type 2 or Shadow Plus rear derailleur
    • 104mm BCD | 30-36T
Wolf Tooth Components 104 BCD chainring

Wolf Tooth Components 104 BCD chainring

  • North Shore Billet – Chainring designed to work on SRAM splined cranks. Simply remove the spider and mount the chainring. These chainrings are made in Canada.
    • SRAM spline | 27T-36T
North Shore Billet SRAM spline chainring

North Shore Billet SRAM spline chainring

  • MRP – MRP makes rings for standard 4 bolt mount and SRAM spline mount. Their Bling Rings and Podium chainrings are made in the USA.
    • 104mm BCD | 30-4oT
    • SRAM spline | 28-36T
MRP Bling Ring SRAM spline chainring

MRP Bling Ring SRAM spline chainring

Home Brewed Components makes their chainrings in many colors

Homebrewed Components makes their chainrings in many colors

  • RCR Fabrication – RCR is fairly new to making bicycle products but have had great reviews. These chainrings are also made in the USA.
    • SRAM Spline | 32T or 34T
RCR Fabrications SRAM X Series chainrings

RCR Fabrications SRAM X Series chainrings

  • Anderson Machines – The mounting for this chainring is a bit unconventional and you need to do a little bit of filing to your crankset. These chainrings are made in the USA.
    • 104 BCD | 30T
  • Blackspire – They make single speed/1X specific chainrings for a wide array of BCD’s.
    • 104mm BCD | 32, 33, 34, 35, 36, 37, 38, 39T
    • 94mm BCD | 30, 32, 34, 36, 38T
    • 110mm BCD |  34, 36, 38T
    • 102mm BCD |  32, 33, 34T

All of these companies also make great products with at least a 32T chainring:

  • Niner
  • RaceFace
  • Hope
  • e.thirteen
  • Renthal
  • Gamut
  • Straitline
Do I need a chainguide?

For most riders a chainguide of some sort is going to be a really good idea. As I mentioned, there are some chainrings being made that are designed to be ran without a chainguide. Personally I’d rather sacrifice a little weight to have the insurance that I’m not going to throw a chain hauling through a rough section of trail.

There are a lot of great single ring chainguides on the market. Most of these guides just guide the chain across the top of the chainring but some options offer more protection. How you want to mount your chainguide is going to be a decision you’ll need to make that fits your bike best. Options usually include bottom bracket mounts, seattube mounts, or even direct mounts on some newer frames.

Suggested chainguides:

  • MRP – 1X, Lopes SL, AMG
(left to right) MRP 1X, Lopes SL, AMG

(left to right) MRP 1X, Lopes SL, AMG

e.thirteen XCX+ chainguide

e.thirteen XCX+ chainguide

Paul Components Chain Keeper

Paul Components Chain Keeper

What type of chain do I need?

There isn’t really anything special to think about when buying a 1X drivetrain chain unless you’re going with SRAM XX1. You just need to make sure it is 9, 10, or 11 speed compatible with your cassette. Make sure you do fit your chain correctly. You’ll want to make sure the tension is set properly so you’re less likely to throw your chain due to being too loose.

Suggested Chains:

KMC X10SL chain

KMC X10SL chain

9-Speed

  • KMC X9SL
  • Shimano HG73, HG93
  • SRAM 971, 991

shopping iconIf you’re looking to buy a 9-speed chain online I suggest checking out Jenson USA for the best selection and prices.


10-Speed

  • KMC X10SL
  • Shimano HG74, HG94
  • SRAM 1071, 1091

shopping iconIf you’re looking to buy a 10-speed chain online I suggest checking out Jenson USA for the best selection and prices.


11-Speed

  • SRAM PC-XX1

shopping iconIf you’re looking to buy a 11-speed chain online I suggest checking out Jenson USA for the best selection and prices.

 

I hope this guide has given you a lot of helpful information and suggestions. Let me know what your experiences with 1X drivetrains have been like in the comments.

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About Author

Welcome! I'm passionate about all things mountain biking. My articles focus on American made products as well as frame builders and riding locations in the USA.

(19) Readers Comments

  1. JA, this is a great article and very helpful. I’m trying to put together a 1×10 setup and the only thing I can’t figure out is the cranks. SRAM has their XX1 and X01 but these are made for 11 speed. There’s an SRAM Truvativ X0 DH setup that looks like it can take a 1×10 setup, but their site is vague if this is a 10 or 11 setup.
    http://www.sram.com/sram/mountain/products/truvativ-x0-dh-crankset
    Wolftooth shows an XX setup but this is meant for a 2×10. Are they just leaving off the smaller ring?
    http://www.wolftoothcycling.com/products/120-bcd-chainrings
    Thanks for your help
    Peter

    • What type of bike are you building? XC, Enduro, DH? That would help with crank selection.

  2. Can I use Shimano XT M780 cranks and change the remove 2 of the 3 chain rings to just one with 32T? I’m building an Intense Carbine AM rig.

    I agree, the section on cranks in this article needs more explaining about cranks for a 1×10 setup, especially using Shimano cranks as this is a common brand that only fits certain bottom brackets.

  3. A quick question, I have a Shimano XT FC M782 crankset with a 104mm BCD and I was going to order a Wolf Tooth 32T chainring, I just wanted to make sure the crank was compatible for a 1×10 if I have a Shimano XT M770 | 11-32T on the back.
    Cheers,
    TW

    • Yes you should be fine. I’d check with Wolf Tooth as well to make 100%.

  4. Is it worth it to run a wolf tooth chain ring without a clutch RD? Frankly I don’t want to deal with the expense of a complete change over to 10 speed (I used to work in a shop, and man does paying retail now stink…). They suggest a 10 speed chain, will that run smoothly with a 9 speed cassette? The old bike mechanic in me says no way, but perhaps you’ve got better insight than I do. Also, I’m planning on riding Moab and Fruita this coming year, to give you context of where my bike would be most relied on to function without a hitch.

    The set up would be, M772 RD, 9 spd XT cass, 9 or 10 speed Shimano XT chain, 32T 104BDC Wolf tooth chanring.

    • I don’t think running a Wolf tooth without a clutched rear derailleur is bullet proof enough for desert riding like that. I’d still with a lightweight chainguide from e.13 or MRP and not have to worry about it.

  5. I used your page to rebuild my new Jamis exile frame that Jamis gave me when I broke my original one, They included a new fork and BB – very generous. I made a 1×10 with E-thirtheen 34t ring which I mounted on my old Shimano 105 crank, Shimano M675 Shadow Plus and 11/36t cassette and Shimano Deore shifter. I did not get a chain guide and to date I have had no problem with losing a chain. The only thing I might try different is a 32t ring, I find myself looking for that one extra gear seeing I love those hills. I built this as my winter bike and it has been a lot of fun to ride and to build. Thank you for your acticle, I obviously took full advantage of it.

    Jon Shuttle, Warner, NH

  6. Hey, I am going 1×9 with a 2007 hardrock I would like to know if I run a mid ring from a triple (the 32)
    With a chain guide (home made one) would that hold or be a complete waste of time? Also do I need to shorten the chain if I have no big 42 up front? Thanks from Israel with a tiny budget ( solder in the idf makeing about 125$ a month)

    • That would work perfectly fine. You will need to shorten your chain a bit.

  7. Anyone building up a 1x? these days should consider the benefits of the OneUp conversion. This extra 42t sprocket allows you to retain a decent “granny” even with a 32t or 34t front chainring. Compared to purchasing one of the 1×11 SRAM options, it’s quite affordable.

    I currently have XO-1 (with 34t chainring) on my Santa Cruz Bronson, and it’s truly a new mindset. So, I’m now building up my new 650b hardtail with an XT 11-36t cassette (with OneUp conversion), SLX long cage rear derailleur (with clutch), SLX shifter, RaceFace Narrow-Wide 34t chainring, mounted to a RaceFace Turbine crank.

    http://www.oneupcomponents.com/

  8. Hi There J.A

    I’ve been runing a 1×9 with 11-34 cassete with a 30 NW Race Face front ring and i love it, but i’m lacking a grany gear.
    Since i’m using a shimano Zee reer mech i could not use the 42 Cog, but now One Up, wolf tooth and Hope all came out with a 40 Cog and 1up states it suits fine with Zee mech. thinking of cassete and adapter cog change…

    What’s your thoughts about that?

    • I’d go for the 40. I think it’d work fine once you’ve got your tension adjusted. I personally haven’t tried this exact setup but it sounds like OneUP has.

  9. Hi,

    would it be possible to combine a XTR (M985) crank with a wolftooth chainring and a SRAM X11 cassette ?

    Thanks!

    Michael

  10. Are any of these setups compatible with road STI shifters, either Shimano or SRAM? I am trying to see if its possible to put together a 1 x 10 or 11 setup with something like a 11-34 cassette with a single 34T chainring for a touring bike with drop handlebars. Thanks for any help.

  11. Hi,

    Great article :-)

    I have a new bike with thenew Shimano 40/30/22 carnk.
    Unfortunately, this crank comes with 96BCD and there is no compatible narrow/wide chainrings in the market (yet).

    I was wondering if I could use the original mid range ring (30T) + a chainguide (I already have a clutch rear mech). will it work?

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