The Diamondback brand was pretty decently regarded by kids on BMX bikes in the early '80s -- sort of an affordable but respectable alternative to Hutch, Skyway, PK Ripper, etc. Centurion, the other brand name owned by Western States Imports, occupied a similar niche for road bikes.

As so often happens with brand names, the Diamondback name fell from popularity and was sold (a few times) to companies who valued the name recognition. The various owners of the Diamondback name have put the brand on bikes of varying quality, some of which you might find at mass market retailers. It happens with all sorts of goods. Look around at the clothing brands in big box stores and you're bound to see at least a few names that used to be popular but have fallen from grace.

In recent years, it seems the owners of the Diamondback name are putting it on decent bikes again. I've got a Diamondback Steilacoom CCX, an entry-level cyclocross bike I use for gravel trails. Shimano Sora drivetrain, Easton CF fork... it's not high end, but it's on par with a lot of bikes at my local bike shop. And DB has a number of better CX and road models than mine.

All of this makes the value of used Diamondbacks kind of a tricky thing... If we're discussing a DB on the used market, is it a good one or one of the cheaper ones? Even if it's one of the better Diamondbacks, the bike's value will likely be hurt by name association with cheap bikes, but by how much? And of course, name isn't the only factor when looking at a used bike. Old hybrids and most old rigid mountain bikes don't command high prices anyway, so the "Diamondback discount" could knock some dollars off an already low value. (Good for bargain hunters looking for a cheap ride. Bad for sellers.)