hey chief, how often did you change out the chain? I know chain life depends on lots of factors and can vary quite a lot from rider to rider and specifics (lots in rain, on dirt roads, fenders or not, how well you keep drivetrain clean and lubed), but I'm curious to your 1x11 experience, as that is a heck of a lot of kms, 17,000 of em.
VeloNews has lab tested the resistance of both 1X and 2X drivetrains, and the conclusion is clear: "2x
is the most efficient across all gears (96.2% vs 95.1% drive efficiency). The main reason for the higher resistance is greater chain angles from the chainring to the cassette, which results in the chainplates scraping harder on the cogs."
You can read about this stuff here, but there is word of caution when you read this article I'll post. And that word of caution is "marketing". The market forces want us to buy the newest and greatest thing, so they'll push that extremely hard and make everything else sound like junk in comparison. And in this article I going to give you it will say what I posted above, but it will also say this: "
2x chains wear out faster than 1x chains. You’ll have to replace the chain, cassette, and chainrings more often." Did you catch a problem here yet? In one statement they say that the greater chain angles will result in chainplates scraping harder on the cogs, then says in 2x you have to replace the chain, cassette, and chainrings more often, well which is it? One of those statements is a marketing lie, and that is the last statement! Anyone with half a brain can see that a chain with only a 1x setup twists more to reach either extreme in the rear cluster, and twisting is more harder on a chain than riding closer to a straight line would be, it would also mean that as the chain goes into those more extreme angles the smaller and taller cogs will wear out faster, and the chainring will wear out faster as well because it has to deal the deflection of the chain. What I said agrees with the first statement that this article says, so here is the article:
1X Vs 2X Drivetrain: Pros and Cons - Where The Road Forks
While on a MTB a 1x would be more durable but that's because you'll be banging it like crazy, a bit different thing going on with MTB vs a road bike. Even with that, you will still get accelerated wear on the chain, cluster, and chainrings. So you have to weigh out which is more important, one less fail point when riding hard, or components last longer, if you're not doing downhill racing I don't really see why someone would want a 1x setup unless you have issues with chain drops due to very rough off road conditions such as downhill racing.
They have been using 2x and 3x on touring bikes for a very long time, and people rarely have a problem with the front derailleur.
But read the site I gave, decide which is best for you.