I'm a biking amateur, but I've been wanting to upgrade and get more serious. Just recently, I was gifted a pretty new bike and I'm wanting to figure out how BSO it is so I can either upgrade it or get rid of it get a new, nicer bike.

What can I check to tell how much of this bike is cheap BSO material and how much will last?

I'm trying to create a part-by-part list so I can decide what's worth it to replace.

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    Welcome to Bicycles @Super :-)
    – andy256
    Aug 1, 2015 at 23:07
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    Does the part have a stamped brand you can look up? Shimano, SRAM, or Campi. If you have to ask it is probably BSO. BSO or not it is not it is rarely worth upgrading versus buying another bike.
    – paparazzo
    Aug 1, 2015 at 23:16
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    @Frisbee they're mostly Shimano. But I kind of hoped this post would stay generic. Aug 1, 2015 at 23:18
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    Parts that are labeled only "Shimano" without model name are generic BSO level. If there is a model name, you can look it up.
    – ojs
    Aug 2, 2015 at 8:53
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    Some useful answers on the dupe at bicycles.stackexchange.com/questions/61746/…
    – Criggie
    May 6, 2019 at 8:59

3 Answers 3


It used to be easier to tell BSOs from "real" bikes, but now the technology is changing so rapidly, and it's much harder.

On a bike older than about 20 years, one would first look at the frame, in two places:

  1. The joints. Better quality frames would be "lugged", with the steel tubes brazed into fittings (called lugs) that secured the joints. Cheap frames would just have the tubes welded together. (Welding, as used then, would destroy the thin, high-strength steel used in better frames.)
  2. The dropouts. Cheap frames would have rear dropouts that were quite clearly just stamped from sheet metal, while the front dropouts would be similar, or would simply be slots cut in the ends of the flattened fork tubes. Better quality would use forged dropouts.

These days the dropouts are still a tell, but not nearly as reliable as before. And frames are often made of materials other than steel, and even steel can now be welded, using a rapid-weld process originally developed for aluminum frames. (Though a good-quality lugged steel frame is still a thing of beauty.)

Other than the frame, the most obvious identifier of low quality is a one-piece crank. This was true 20 years ago and is still true.

Well, I'll take that back -- one more thing: Twist shifters are highly suspect. They are cheap and have an extraordinarily high failure rate. There presumably are some good quality twist shifters, but they're the exception.

Make that two more things: With a multi-speed bottom bracket, check the material used to make the chainrings. Very often BSOs have steel rather than aluminum chainrings. A better quality bike may have a steel "granny" ring, but the others would be aluminum.

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    +1 Nice summary. Frisbee (and I) think a lack of "name" groupset components would be an indicator also. What is your thought on this?
    – andy256
    Aug 2, 2015 at 8:26
  • A lot of BSO's still use horizontal dropouts. Aside from Surly, I can't think of any other decent manufacturers who still uses them.
    – Batman
    Aug 3, 2015 at 2:40
  • Batman, all BMX bikes have horizontal dropouts. That's a lot of bikes, and a lot of decent manufacturers.
    – user23374
    Feb 7, 2017 at 16:09
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    Why would aluminum chainrings be a sign of quality? Chainrings must withstand mechanical wear - not the part that can trade durability for weight reduction. I want them to be as tough as the chain, which should also be steel. Oct 17, 2018 at 22:20
  • @cmaster - Mainly weight, I suspect, but steel chainrings are often crudely stamped and lack the precision of a decent quality aluminum ring. Oct 17, 2018 at 22:23

Is the bottom-bracket a cartridge unit? (googling this should give you an idea of what one looks like) If it's not, you definitely have a BSO and you should install a cartridge bb.

Look at the hubs. What brand are they? If there is no brand marking on the hub body (or skewer) it's a bad sign. If this is the case, you should probably replace the whole wheel, because the rim likely isn't worth it's salt either.

I really haven't had problems with cheap shifters and brakes. Cheap derailleurs will work well as long as they're adjusted correctly, same with cheap rim brakes. If the brake pads wear out, change them for something nicer, but before then don't bother.

Are the cranks steel or aluminum? If they're steel, they will work, but changing them is a good idea.

I second DRH's point about 1-piece cranks, but bear in mind that there are many junk 3-piece cranksets too.

DRH made some good points about the frame, but IMO as long as you weigh less than 200lbs, a cheap frame will be okay if you're not riding on rough stuff.

Upgrading the frame is in the same vein as upgrading the cranks. You could stick with the BSO-grade stuff, but you'll enjoy the bike a lot more if you upgrade. Same deal with the tires, too. Cheap, heavy ones will work, but the bike will be faster and more comfy if you upgrade.

If your bike has full-suspension you should change the frame. Seriously, you don't want full-suspension on a cheap bike.

If your bike has a front suspension it may be worth upgrading. If the fork is a Suntour, I wouldn't upgrade, but if you're feeling rich, get a Rockshox.

If the bike has a horrible Zoom or similar fork, you should upgrade to at least a Suntour or install a rigid fork.

If your bike fails all of the quality tests I mentioned above, you are probably better off selling the bike than you are trying to upgrade the components.

  • 7
    Who better to answer this question :-)
    – andy256
    Aug 3, 2015 at 0:33
  • BTW, nice pic. Are you going up or down? (Or just stationary, I see a foot down :-)
    – andy256
    Aug 3, 2015 at 0:34
  • The weakest part of recent BSOs is probably the shifters. Almost universally, twist shifters are used, and poor quality twist shifters have a very high failure rate. Aug 3, 2015 at 2:22
  • A lot of cheaper but decent bikes have non branded hubs.
    – Batman
    Aug 3, 2015 at 2:42
  • @andy256 Yeah, I'm stationary in that pic :)
    – BSO rider
    Aug 3, 2015 at 11:11

Possibly one of the easiest way to look up if a bike is a BSO or not is google it or look at where it was bought from. Walmart/Target/Kmart/etc. means BSO.

The brand is also easy to tell. Most non-bso's in the US are made by Giant, Trek, Specialized, Cannondale. Some brands are a bit harder since they sell both BSO and non-BSO (e.g. Schwinn, which does their non-bso's under the name Schwinn Signature bikes).

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    I bought a Schwinn Signature bike a few years ago from a local bike shop, and promptly put 10,000 miles on it. It may not be a BSO but there are still cheap components that ought to be replaced before doing any serious riding with it. On mine, within the first 500 miles I had to replace the bottom bracket cartridge, the rear wheel (so I could carry more weight) and the horrible BSO-style plastic pedals, one of which actually broke. (Who does that?!) Otherwise it has been quite a decent bike. Jan 4, 2020 at 6:01
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    Sure. Even cheaper quality bikes will need parts (and expensive bikes too); corners are always cut for price and profit reasons, and also since people will have preferences on what they want to replace with (e.g. saddles, wheels, pedals; more expensive bikes might not even come with pedals).
    – Batman
    Jan 4, 2020 at 16:40

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