There are several companies most associated with cheap bikes in America. Below is a rough profile of the major players. (In reverse alphabetical order.)
Schwinn is pretty much the name people most associate with American Bicycles, even though none of its bikes are currently made in America. Schwinn sells bikes across the price spectrum. From $80 kids bikes to $2700 e-bikes. They make pretty much every kind of bike, each with a wide variety of prices. There are two major groups of bikes, the “standard” and the “signature” series. You won’t find the signature bikes at the big-box stores and very few of them qualify as cheap bikes. The standard series is what us cheapies know of Schwinn.
Pacific owns several brands, including Schwinn, Mongoose, Iron Horse, Roadmaster, and also sells bikes under its own name.
Next is mostly focused on bikes for kids through teenagers, though they do at times sell adult bikes. Their mountain bikes seem sturdy, based on looking at used examples for sale, but are heavy beyond bike snob acceptability. Earlier in their existence they were prone to safety recalls, but they seem to have put that problem behind them.
Mongoose, like Schwinn, another Pacific brand, makes a variety of bicycle type with a variety of prices. In come circles Mongoose bikes are their dirty little secret. Most people think of what they see in the big box stores but certain model Mongoose BMX and Mountain bikes are prized possessions. It takes a little research to find which models are better than others.
Magna is owned by the same company as Next. They offer many similar bikes but Magna offers a wider variety of adult bikes. Like many other cheap bike companies, they tend more towards being heavy to ensure durability. Their bikes are nothing special, but mostly there’s nothing wrong either. The exception seems to be their dual suspension mountain bikes. I’ve seen more of these broken at yard sales than any other brand of bike. On the other hand, their single and no suspension mountain bikes seem to be able to take more than their share of punishment.
Kent started as a bike shop in New York in 1909, and is still a family-owned business. Their specialty is importing specialty-branded bikes. They are responsible for the GMC Denali road bikes, the Jeep mountain bikes, Spiderman kids bikes, etc. In fact I ride a Lamboghini Rapido that was imported by Kent. (To my surprise it is nut and bolt identical to the GMC Denali.) They also sell some bikes under the Kent name. In fact they have a tandem bike that has a very good reputation.
Huffy is, like Schwinn, synonymous with American cycling. And like Schwinn they make a wide variety of bikes, though one segment they skip is the road bike, and they don’t have an equivalent of Schwinn’s signature series, concentrating on the lower end of the spectrum. I had a Huffy Mountain bike a few years ago and it performed well. It was heavy of course, but I weight 265 at the time so it needed to be. I gave it to a friend when I got my road bike and he is still using it for his daily commute.
Cycle Force Group
CFG is a lot like Kent. They import several brands of bikes. My favorites are the Smith & Wesson police bikes, and a series of cheap road bikes under the Tour de France label.
Of course you will see other brands of cheap bikes in stores, but do your research and you will probably find that the brand is involved with, or a sub-brand of one of the companies listed above. If they aren’t does that mean they’re bad? Not necessarily. Bike brands come and go on a regular basis. Some are good and some are bad. Compounding the problem is the fact all you need to become a bike importer is a PayPal account. You market the bikes here in America, you see a lot of this on eBay, then you order the bikes and the wholesaler in China ships the bike right to your customer. Some of these bikes are actually overstocks of big name bikes rebranded. Others are garbage that if you left it unlocked on the street they would still be there a month later.
Do your research.