I'm looking at getting a decent mountain bike that will probably spend quite a bit of time on the road.

I found that the most common types of chainsetsare either:

  • Shimano Altus 2x9
  • Shimano Deore 1x10 (on the more expensive models).
  • SRAM SX Eagle 1x12 (on the much more expensive models).

When I compared the ratios of these three chainsets, the Shimano Altus seems to have lower low end speeds and higher high end speeds, so in general it seems like the better option to me. Yet I can't understand why the 1x Deore and 1x SX Eagle are the more expensive options, aside from the weight loss, is there any other benefit to them or is this really just a case that the Altus is better? At least in terms of speed (which is what I am mainly interested in).

Am I missing any other important comparisons? Aside from weight and I guess it being easier to switch gears in a 1x setup (i.e. chain not crossing and stuff).

  • 1
    Are you basically asking if 1x chainsets are better than 2x and is it worth the price?
    – Mołot
    Commented Aug 17, 2020 at 22:38
  • Well I'm struggling to understand why the 1x chainsets are better and more expensive. To me, being able to go as slow as possible and as fast as possible is the most important thing and the 2x chainsets seem to be a lot better for that and cheaper. So what I am really asking is am I right? Am I missing anything else important?
    – KillerKode
    Commented Aug 17, 2020 at 22:50
  • 3
    Which is more important to you, the offroad time or the onroad time. Optimise for the most enjoyable part and put up with a not-ideal bike for the boring bits.
    – Criggie
    Commented Aug 18, 2020 at 3:15
  • First find a few bikes that have the wheel size and geometry for the purpose you're after. Then take them for a ride and get a feel of them and to understand the fit. After you've narrowed it right down start comparing groupsets (standards, brakes, suspension and wheelset also) of the different spec levels to decide on what you're after. Groupsets and brakes are among the cheaper things to replace so don't base a purchase decision on them.
    – DWGKNZ
    Commented Aug 18, 2020 at 19:13

3 Answers 3


You are mixing quality with quantity (on this case gear range).

1x in a true MTB setting gives more than enough range for a majority of riders most of the time. MTBers on 1x tend to elect a chainring that gives the lowest low gear they need for climbing, and accept the limited loss of time that occurs the few times they are spun out at high speeds. Reality is if a technical MTBer is going fast than spun out speed, they are concentrating on lines, jumps and landings, speed is far from a priority. The advantages (listed in the answer by @MaplePanda) out weight the loss of top gearing.

2x is useful for those who ride big hills on roads and need a low gear for climbing and a high gear for high speed descents, or weaker riders than need super low gears for hills. Until recently 2x has also been a viable choice for budget, but 1x is now avaible as some quite low price points. The 1x fanboys often come with a 1 eyed view of its advantages, most of which suit experianced rider significantly more than inexperiacned riders (eg. Anyone thinking about Altus or SX is not a weight weenie, probably cannot afford a dropper and almost certainly buying a hard tail where there is plenty of room for a front derailluer)

There are many other group set options on bikes - if you cannot find what you like at the price point you can afford, keep looking.

In terms of quality, Deore is (IMHO) the best in the list you have given. Altus is considered too low quality for reliable operation MTB standards, but is suitible for road and occasional light offroad use. SX Eagle is somewhere close to the Deore in quality - probably comes down to personal preference.

  • Thanks for the shoutout. SX is arguably worse than even Altus: it uses square taper cranks, the rear derailleur is plastic (and wears out after several hundred km or so, and the replacement is still $50), the cassette weighs an absurd amount, etc. The points regarding a dropper and front derailleur are more general/inherent benefits, which I agree, aren’t going to be necessarily applicable in this case.
    – MaplePanda
    Commented Aug 18, 2020 at 5:02
  • Seems like a great answer, the only thing I'm not sure I agree with is the first line. Not sure where quality comes into the equation, as it seems the 1x setups are more expensive, I don't think they are more expensive because they are any better quality? I think they are more expensive for the other reasons you have mentioned in your answer right? I don't think quality applies in this case.
    – KillerKode
    Commented Aug 18, 2020 at 13:19
  • @KillerKode Well, Deore is a big step up in both quality and price compared to Altus. SX is just overpriced. 1x wide range cassettes tend to be more expensive due to the intricate manufacturing processes needed to keep them lightweight yet strong. Bikes with a 1x are also intended more for serious MTB use and they are likely to be higher quality over all.
    – MaplePanda
    Commented Aug 18, 2020 at 17:27
  • 2
    @KillerKode The more expensive ones have features that are very useful for some types of off-road use, such as a clutch derailleur. As the answer says, you need to consider your use case, and judge what's worth it based on that. Usually, more specialized things also get more expensive, but they're only better for their specific use case.
    – Szabolcs
    Commented Aug 18, 2020 at 17:28

First off, the higher end stuff is lighter. SRAM SX is built extremely cheaply, it is worse than Deore by far. Much like how cheap bikes are known as "bicycle-shaped objects", SX is known as a "groupset-shaped object".

You also need to take into account your riding style: just how much gear range do you need? Seeing as you intend to ride on the road quite a bit, I would definitely go for a 2x system.

So why is 1x better for MTB?

  1. The shifting pattern is much simpler. You don't have to to worry about cross chaining or redundant gear ratios or any of that. It's simply "bigger number = faster, smaller number = slower". With a 2x or even worse a 3x, it is easy to lose track of which gear combo you're currently in. It's also less fun to be constantly thinking about gearing.
  2. Having exactly the perfect gear ratio is not as important because of the constantly changing terrain. You also don't need to pedal as much on the downhills, so really all you need a drivetrain for is the climbs and flats.
  3. Better frame design is possible without having to accommodate for the front derailleur.
  4. Lets you run an under-bar dropper lever.
  5. Lighter weight and more reliable as it has fewer moving parts (no need to adjust the FD anymore too). The "narrow-wide chainring" and "chainguard" are two examples of devices you can use on a 1x system to stop the chain from falling off as much.
  • You missed a space after "2." in your second bullet point, and it messedup your list a litte. I don't have enough reputation to correct single character mistake
    – Mołot
    Commented Aug 18, 2020 at 7:28
  • @Mołot Thanks, fixed.
    – MaplePanda
    Commented Aug 18, 2020 at 17:23
  • 2
    Another point: at least for road bikes, front shifting is never totally without risk of dropping the chain. Chain drops happen during front shifts even for professionally-maintained bikes at the highest levels of road racing such as the Tour de France. (In 2010, the amount of time Andy Schleck lost to a dropped chain was more than the amount of time he finished behind Alberto Contador...) Going to a 1x front eliminates the risk of dropping the chain. Commented Aug 18, 2020 at 17:52

Might I suggest two shopping options you may not have considered?

  1. Buy a higher-quality used bike, say 5 years old, and have it thoroughly checked and prepped by a bike mechanic. You should be able to find a lighter, better frame and a good quality 2x drivetrain (or whatever you want).
  2. If buying new, see if the bike shop will swap out stock components for those more to your liking. For example, a better quality rear derailleur (my Shimano rule of thumb is Deore or better). There are plenty of quality "NOS" (New Old Stock) components available from past model years, so a bike shop should be able to find and install (e.g.) a new Deore 2x drivetrain in place of a stock Altus. The shop will then later sell the "take off" components, so you should get somewhat of a discount on the NOS components or their installation.
  • 1
    "for example, a better quality rear derailleur" Imho the rear derailleur is the least important component of a groupset and the most likely to break.
    – Michael
    Commented Aug 18, 2020 at 6:47
  • @Micheal To be fair, Deore is the cheapest derailleur with a clutch. That alone may be worth the upgrade cost.
    – MaplePanda
    Commented Aug 18, 2020 at 17:29

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