So I'm looking into getting me an affordable mountain bike (more details in that thread) and I was researching some upgrades. I've always seen people dumping on coil forks and how they're inferior to air forks, but I've also seen people swear by coil forks. So my question is, if I figure I don't really need to be splurging on a quality air fork, what kind of coil fork should I be looking at that's got such niceties as... I don't know, being reliable, and having rebound adjust? I mean Google doesn't make it easy; most of the search results are from Aliexpress and Timu!

Cheap is the problem here not coil vs air. There are plenty of really good coil forks but they ain't cheap.

1. Are you saying that good coil forks are so expensive I might as well spring (pun totally intended ​ ​​​​​) for an air fork anyway?

2. Could you name a few? (straight steerer, 100mm open dropouts)

The good coil forks are mostly dedicated for more enduro/Dh uses where the added weight matters less so 100mm is going to be hard to find. Even more so one with a straight steerer and QR.

If you're interested in inexpensive, 100mm, straight steerer, look for previous years Rock Shox models. They can be had for $100 sometimes and work well enough for most applications (although the "purists" will not agree) and are SAFE.

My bad - I should've worded my reply more carefully. By 100mm I was referring to open dropout spacing; the bike in question comes with 120mm travel fork and shock, so if I'm going to be upgrading, I'm going to get like for like.

For a coil fork on an entry level bike, I'd consider the Rock Shox XC30 or XC32 to be decent. If the main idea is to use the bike as a mountain bike, I'd still spring for an air fork though, shaving weight off the front end and being able to easily tune it to your weight by adjusting air pressure is a pretty significant advantage.