It used to be that when it was time to buy my son a new bike, we’d take him to the store and let him try a couple out. Usually just him sitting on one for a few moments was enough to tell us if a bike was too small, too big or just right. Well, around here in Eastern Pennsylvania (and in many other areas), bikes have been out of stock for months. And even if they weren’t, I’d have no intention of taking my son into a store to try them out. Which is why, of course, his bike broke a few weeks ago.
One moment we’re riding along all peaceful-like, and the next moment, he’s on the ground with the bike on top of him, a broken pedal a few feet away and a kind woman trying to offer socially distanced assistance hovering nearby. (He’s fine).
New pedals are easier to come by — and much cheaper — than a new bike, so we tried attaching one of those first. But the problem, it seemed, went far beyond a replacement pedal. Given that the bike was really getting to be too small for him anyway, and not wanting to spend money to get it professionally repaired, we opted to go in search of a new one — online.
The thing about ordering a bike online is that it’s practically impossible to tell how big it is from a picture. And although bikes are often categorised by their wheel size, that measurement isn’t the end-all, be-all of proper bike fit, even if the bike is marketed for kids who are your child’s age. That’s because not all bikes with 14-inch wheels are created equal in other measurements — most importantly, seat height.
Another measurement you don’t want to put too much stock into? Basing your buy on your child’s full height. Two kids measuring 48 inches tall might not sit comfortably on the same bike — because it’s not their height but their inseam measurement that matters. That’s what will determine whether their feet will be able to reach the ground while they’re sitting, so that’s where you should start.
Measuring their inseam
Measuring an inseam for bike fit is a little different from measuring for pant fit — you want to reach the part that will be on the seat, not just slightly below the crotch. So here’s what you do:
1. Have your kids put on their sneakers. They’ll be wearing them while they ride and it may impact the measurement a bit.
2. Have them stand tall, with their feet against the wall, shoulder-width apart.
3. Place a book (any size is fine) between your child’s legs and slide it up (gently) as far as it can go.
4. Measure from the ground to the top of the book. If you’ve got two adults to help, one can hold the book while the other measures. If you’re solo-measuring, raise the book up as high as it can go and then have the child scoot forward a bit away from the wall. While holding the book in place and level with the ground with one hand, mark the wall where it meets the edge of the book with a pencil. Then, measure from the ground to the mark.
Compare their inseam with the bike seat’s height range
Most bicycle seats are adjustable, so the bikes you’re considering should display seat height as a range,. This is especially helpful for growing kids: You want to buy a bike that fits them now but also one they can grow with for a while. If their inseam measurement is already in the upper range of the seat height, you probably want to find another option or it might be too small for them come next spring.
On the other hand, if they’re barely at the minimum of the range and they’re not a confident rider, it may be a little too much bike for them to handle. A strong, confident rider can be higher up on their toes than newer or less confident riders.
OK, now you can think about wheel size
Wheel size isn’t the most important thing but it does matter, so now you can compare. Depending on your child’s inseam measurement, they may fall within the range of two different wheel sizes. Here’s a general guideline from Two Wheeling Tots:
If they do fall between two different wheel sizes, Two Wheeling Tots recommends you opt for the larger wheel, so they’ve got more room to grow and can get more use out of the bike.