What to look for when buying the new rim (assembled with spokes)

Question

I need to replace my rear rim one more time, because it is very difficult to mount a tire on it. Can I look for something that would help me to avoid this problem second time? Parameter, dimension, characteristic?

Obviously, the wheel diameter must match (27.5") and I will buy that is classified as "MTB rim". It must be suitable for the disk brakes and I will need to relocate my disk and cassette (9 speed Shimano Deore) to it. Do I need to watch for something more?

To be precise, I plan to buy the part consisting of the rim itself but also spokes and hub/freewheel - the most complete thing available to me. I still need to relocate the tire, cassette and the brake rotor.

Answer 1

First, as said in the comments, I'd be surprised that changing the rim would solve the issue of changing the tire. Some brands/models of tires are more difficult to install, tubeless-ready tires may also be a bit harder to install.

The "compatibility" things to pay attention to when choosing a wheel are:

1. the rim diameter (you already know it is a 27.5")
2. the way it's attached to the frame: quick-release or through-axles
3. since you mention a MTB, whether it's a "Boost" (=wider) axle or not.
4. the kind of brakes: disc or rims. For disc brakes, you have two standards: 6-holes and Centerlock. 6 holes is said to be more universal, Centerlock is a Shimano standard (in other words, a "de facto" standard). The relative positioning of the rotors is the same, choosing one or the other is mostly a question of "maintenance strategy" (for example, if you want to have the same standard than with the front wheel).
5. the inside width of the rim. There are compatibility charts to help you with that, the main parameter to choose a width is the width of the tire, that you don't give. Larger is better, but if you use your bike as commuter, only marginally.
6. the freehub body type: you mention 9 speed, so that's easy: Shimano Hyperglide (there are other names, but as long as you don't see XD, XDR, Microspline or Campagnolo, you're good).
7. if you want to be able to have tubeless tires or not. In that case, you need tubeless-ready rims.

And now there are the "bonuses":

• the depth of the rim: deeper means more rigid vertically. It's more critical on road bikes (for rigidity and aerodynamics). On MTB shallower rims are preferred for compliance, I don't think that there is so much variation in the offer.
• bearings: cups and cones vs sealed. Cups and cone are said to be more durable, if properly maintained and adjusted, and you can replace the cones and the bearings if these components are worn (proprietary parts — sourcing is a problem if the brand is not widely distributed, so I'd only take this options with Shimano hubs). If the cup is worn, you usually need to replace the whole hub — which up to mid range products means the wheel, as a hub + a set of spokes + labour often cost more than a complete preassembled wheel. Sealed bearings need to be replaced when worn out, and since they include the equivalent of the cup, no risk of replacing the hub because of wear of the cup. If you choose sealed bearings, it's however important to choose hubs that use standard industrial bearing instead of proprietary ones.
• modularity: if you want to widen the possibilities to some future upgrades, or if you have several bikes and want some "compatibility" between them, you may prefer a hub with modular design. Some brands of hubs/wheels design their product so that it's easy to change between quick-release and through-axles (only between 135mm quick-release and 142mm through-axle, or their "Boost" equivalent), and sell different freehub bodies. Other brands sell their hubs as is, and you can't change afterwards. If you want to have the possibility to replace your 9-speed with a 12-speed with a 10-tooth small sprocket later, better to choose a modular hub then.
• straight-pull spokes vs j-bend spokes: to put simply, straight-pull spokes are apparently more resistant and easier to replace, as you don't have to remove the cassette and the disc to replace them, but are generally proprietary. J-bend spokes require more work to replace but are universal. This point is important if you want to be able to replace spokes yourself, and in special conditions. For example, some straight-pull designs allow to replace a spoke without unmounting the wheel from the bike, with minimal tools (useful in a bikepacking trip for example, assuming you take spares with you). While with a J-bend, you'll have to unmount rotor, cassette and often tires. You can ride with a broken spoke to a shop, so that more a matter of personal requirements.