Need help with Drivetrain Update

[Aerojack7654]

Hello everyone, I'm an older lifelong cyclist that recently had my beloved old yeti mountain bike stolen, and to try and fill that void, I picked up a 2015 Specialized Crosstrail (I'm riding more paved and gravel trails these days, my full-on mountain bike days are over!). The bike was in very good physical condition, apparently very lightly used. I was unable to ride before purchase, but it looked good and the price was right, and as an engineer that's handled most of my own bike mechanical work over many years of riding, I jumped on it anyway.
For the most part the issues were minor and easily addressed, but as I started taking the bike on some of the steeper trails in my area, more and more problems with the drive train began. It's ostensibly a 3X9 arrangement, which in my experience is a negative, since getting the set up so that the entire rear gear set can be accessed by the 3 front gears is touchy and in my experience, I usually ended up chasing my tail with adjustments, especially as the mechanism aged. I eventually had this problem on my yeti that started with a 2X8, or something like that. At the time, I decided to add an early SRAM 1X11, which I installed myself, and it made the bike much more rideable, albeit in less hilly terrain.
Sorry for the long windup, but I'm considering replacing the 3X9 with a new SRAM 1X14 drivetrain, but I'm worried that the 14-gear stack is going to end up too big to fit where the Shimano 8 gear rear stack was. It appears that the latest SRAM gear stack has thinner gears than the older Shimano, but I'm wondering what other folks experience has been. I've been trolling YouTube to try and get some info in this regard, but so far, no success.
Thanks in advance for any helpful information!
Jack

[ReapThaWhirlwind]

I've been riding 1x setups for years now. In my opinion, 14x is probably overkill. You're looking at other complications, especially if you're concerned about being mechanically inclined, as the higher gear number you go up, the narrower the components get. And thus, the higher maintenance they are to keep in top running shape, because the error margin is less.

For the best versatility, you'll want to go with an 8 speed setup with a larger range. If you truly want a higher gear number, note that the Shimano Cues series specializes in 1x aesthetic, with very high gear ranges to maximize versatility. You might just want to slap one of those in, and they're pretty economical as well. Otherwise, I would suggest your biggest upgrade will actually be switching to an oval chainring for your 1x setup. Then going with an 8 speed setup with a 32T or 34T cassette.

For the main ring, note that the larger ring you use, the more efficient you will be in the lower gears. Ideally, you want to use the largest ring possible. And by running the ring at the back of the crank (if possible), you will maximize the chainline versatility for the 1x setup. The problem with that is...your ring will hit the chain stay when mounted in the back if it's too large. You may have to run a smaller chainring if mounted in the back. Possibly the maximum will be a 40T. But typically, 38T is the largest oval chainring you can run mounted at the back of the crank. I would suggest a 46T oval ring if the ring is mounted in the front, with a 34T cassette for maximum versatility. That's a small ring for me now, but what I would use for commuting to get high efficiency. Otherwise, you can experiment with 42T or 44T, but you should probably just do the 38T. Because that will give you great versatility, and unless you like grinding, you'll have plenty of power to ride comfortably thanks to the oval benefits.

Altus M310 8 Speed Derailleur (Oversized pulleys for maximum efficiency).

8 Speed 12-34 Cassette or 12-32 Cassette

38T // 44T // or 46T Deckas Oval Chainring BCD 104 (Affordable and effective)

Jiankun iXJ Hollowtech Crankset (Affordable, 104 BCD, installs just like Shimano and uses Hollowtech bottom bracket).

Note that if you purchase an off brand Hollowtech bottom bracket, such as Tanke, some of these off brands have different sized cups that don't match the Shimano aesthetic, so they use a different spacer setup. The Tanke brand will not use any spacers if installed on a 73mm shell. And it will use one 2.5mm spacer on each side if installed on a 68mm shell.