Kids/Youth USED Bicycle Purchase Guide (for the layperson)
This guide might be a complete bore for the bike mechanic or hobbyist. Nothing here about hydraulic disc brakes, 12-speed cassettes, "one-by" chainrings, tubeless tires, carbon frames or air suspension.
This guide is aimed mostly at parents (who bike only occasionally, and usually with their kids) looking for bicycles for their children. Something inexpensive knowing that their children will grow out of it anyway. Also factor in the possibility of abuse or theft.
If you decide to shop around for a USED bicycle for your kids, there is a checklist (later down this page) of what I consider important things to check when inspecting a used bicycle to catch any red flags indicating that the bicycle would be more trouble than it's worth for someone with no experience in bicycle repair.
Narrow your search BEFORE selecting candidates
Type: You'll need to know if your kid wants a single-speed, BMX look, or a multi-speed mountain bike (MTB) look.
Sizing: Is the bicycle the right size? A simple bicycle sizing scheme in North America is wheel size in inches (ex: Kids bikes are usually 12/14/16/18; Youths are usually 20/24). When you start going into Adult bikes, you'll hear 26/27.5/29 inch or 650c/700c but the bikes will be sized Small/Medium/Large/etc. at this point, so refer to each brand's sizing guide). You'll bring your kid anyway, but knowing what size to look for will help narrow a search down. For example, if your child outgrows a 20-inch bike, look for a 24-inch bike as a start.
Material: Steel (you may also see Chromoly, which is a steel alloy) is HEAVY and prone to rust (when the paint gets scratched) but it's cheap; Aluminum (spelled Aluminium everywhere other than the USA or English Canada) tends to be lighter and what you should go for unless you want to give your kid a workout :-). Not talking about carbon fiber here because this article is scoped to kids or youth bikes.
Where to look
You may be able to find a used child's bicycle at a low price from an organization in your area who receives bicycle donations and whose bicycle mechanics repair them and bring them back to life.
You'll find more of these organizations in major metropolitan areas.
Being in Ontario (Canada), the ones I know off the top of my head are:
Please consider donating any used bicycles and bicycle parts to those wonderful organizations when you can to keep this system going. Some will often accept bicycles and parts in ANY condition; others can even come to you and pick up your bike if you live close enough.
Otherwise search your local online classifieds. Canada has Kijiji and many others.
Avoid discount department store bikes. If you don't know what these are, the easiest way I can (over)simplify this concept is:
Go to Wal-Mart and avoid any bikes of the brands you see there.
Avoid every brand that Canadian Tire carries (especially Supercycle; they are the worst) except mayyyyyybe Raleigh AND if both shifters and derailleur are Shimano (especially EZ-Fire trigger shifters; those are considerably better than grip shifters). I am not saying that Shimano is necessarily good or bad (Shimano has its low-end stuff and its high-end stuff too; you will see Shimano's absolute lowest at department stores) but it's slightly better than the impossible-to-shift (even for an adult) rubbish off-brand shifters I see on less expensive bicycles (but it could also be partly attributed to poor assembly at the department store). You get what you pay for.
Speaking of low-end Shimano... be wary of bikes that take pride in saying "Shimano equipped" or with Shimano stickers all over... only low-end bikes do that, and you better believe it's going to be the cheapest drivetrain that Shimano has available... or only the derailleur (and perhaps the freewheel too) is Shimano, but the shifters will not.
At SportChek, the only department store brands I would consider would be Jamis (but sadly it looks like SportChek has stopped selling Jamis bikes; they drastically reduced prices to quickly clear inventory, which is usually a sign that they stopped doing business with them). I used to also mention GT but looking at SportChek, I see GT offerings for CAD500+ dollars that have off-brand 7-speed freewheel, derailleur and grip shift (thumbs wayyyyy down) along with false advertising / unskilled staff error. I am losing respect for SportChek, especially after an uninformative canned response I received about my inquiry for why they do not stock Jamis bikes.
Good brands off the top of my head (in no particular order): Giant, Trek, Specialized, Cannondale, Norco, Kona, Scott, Rocky Mountain, Santa Cruz, Jamis, Devinci, MEC
Brands that require some investigation (hit or miss) as to their individual components for the price and for your use case: Raleigh, Schwinn, Northrock, GT
Brands that used to be awesome in the 80s BMX scene (ex: Mongoose?) seem to have lost their way by selling to department stores and at first glance might be crap (prove me wrong) due to lower-end componentry to compete in this low-end market.
Checklist
If you are checking out a used bike from an individual seller, this is what you need to check during your inspection: (Check each checkbox as you complete each task)
Frame:
Tires: Tires do not last forever. Tires may look good from far away, but really look at the tread from up close. For the type of bicycle you are looking for, it's OK to purchase inexpensive bicycle tires from a department store, but factor the cost of those new tires in your assessment if the bicycle needs it.
