What's a good, reliable mountain bike drivetrain (1x10?) I'm thinking about switching my Salsa El Mariachi 29er mountain bike from singlespeed to gears. I love the reliability and simplicity of the singlespeed, but I've been doing more rides that involve both road and trail riding, so it's tough to find a singlespeed gear ratio that can do both. 

I do lots of really long (~75 mile) rides and some multi-day bikepacking trips through the Colorado backcountry, so I need a drivetrain that is really, really reliable. I'm also fairly tough on components (currently, I replace my SS drivetrain each year), so I want to get something that's not too expensive. I currently am running a bashguard (using a SLX triple crank), and I'd like to keep running a bashguard since it's awesome to have one. 

I was thinking of running a 1x9, or maybe 2x9 (with bashguard) setup with SRAM X9 or X7 components. But then I read some great reviews of the new clutch derailleurs (Sram "Type 2" or Shimano "Shadow plus") - people are saying that they keep the chain running lot nicer than the old type derailleurs. I've heard good things about running a 1x10 with the new Shimano Zee derailleur. The many drivetrain options are getting a little ridiculous!

So, what do you think? What drivetrain will keep running through the dust, mud, and crashes, while still keeping the price to something reasonable? 

Thanks, Dan
I won't suggest any brands but here are some ingredients that will allow you to go cheap and reliable:


go 1x9. 2x is more expensive, more noisy, heavier and generally problematic if you can get away with 1x. Just make sure you calculate some possible ring and cassete options so you know that you'll be able to tackle all ascents and descends you need to. A spreadsheet works great for that. Divide ring teeth to cassette teeth to find the ratios that you need. Ride friends' bikes on ascends and descends for find your numbers.
bashguard: Do you really need it? Please check on your existing one whether you see impacts. Have you used it so far? If not, you don't need one. Especially now that you'll go to a single and smaller ring, chances that you really need one are very slim.
chainring: Go with a "narrow-wide" one. There are at least 5 companies making such rings now. The narrow wide pattern of the teeth allows for maximum chain retention eliminating the need for a chain guide.
rear derraileur: Definitelly go with one which has a clutch mechanism. It does work wonders.
crank: You'll most probably be able to use your current SLX crankset, but I'm not 100% sure on that. There is a possibility that you'll need to do some research and play around with spacers in order to have the perfect chainline so all cogs of the cassette are working well.
chain: If you go 1x9 get a 9sp chain. If you go 1x10 get a 10sp chain.