Best Kids BMX Race Bikes (Micro, Mini, Junior, Expert)

So you want to get your child a good BMX race bike. But what size do they need? What brands are good? What else do you need to consider?

This guide is here to help you figure all of that out. We’ll go over the sizes of BMX race bikes, which size your child needs, the best brands and their offerings, and other things you should think about when buying your child a new bike.

Kids BMX Bike Sizes Explained

If you’re new to BMX racing, the bike sizing can be very confusing at first. The naming convention is very different than most kids bikes which are sized by their wheels–i.e. 12 inch bike, 14 inch bike, etc.

There are four sizes of kids BMX racing bikes:

• Micro Mini (under 5)
• Mini (5-7)
• Junior (7-9)
• Expert (9-11)
• Expert XL (10-13)

Teens can fit on a regular adult (Pro) BMX bike, so we won’t focus on those in this article. That said, if you’re looking for a BMX racing bike for your teen, you can still choose a bike from one of the brands we list below.

BMX Bike Size Chart

If you’re not sure which size BMX bike your child needs, this chart should help as a good starting point. Keep in mind that height is a better indicator than age. As we all know, kids grow at different times.

It’s also helpful if your child can try some of these sizes before buying, especially if they are right in between sizes. Many local tracks offer a rental or loaner program.

Size	Age	Height
Micro Mini	<5	3’6″-4’0″
Mini	5-7	4′-4’4″
Junior	7-9	4’3-4’7″
Expert	9-11	4’6″-5’5″
Expert XL	10-13	5’3-5’7″

Kids BMX Race Bike Brands

Listed below are our favorite brands for kids BMX race bikes and their line-ups. Whatever age or size of your child, you’ll find a bike for them.

DK

DK makes great BMX race bikes, and they are (relatively) affordable, which makes them attractive for families just looking to try out the sport. In fact, this is the brand we got for my son’s first BMX bike.

Where To Buy: DansComp.com

DK Lineup

Bike	Size	Price	Weight	Top Tube	Wheels/Tire	Crank
Swift Micro	Micro Mini	$549	16.3 lbs	16.25″	18 x 1”	120mm
Swift Mini	Mini	$549	16.3 lbs	17.25″	20 x 1-1/8”	140mm
Swift Junior	Junior	$549	17.3 lbs	18.25″	20 x 1-3/8”	155mm
Swift Expert	Expert	$549	20 lbs	19.5”	20 x 1-3/8”	165mm

GT

GT offers two series of kids BMX bikes: the Mach One and the Speed Series. The Mach One is intended as an affordable, entry-level race bike, while the Speed Series is meant for some serious racing.

We appreciate that while the cost of nearly everything has gone up in the last few years, the GT BMX prices have remained pretty steady.

Where To Buy: GTBicycles.com

GT Lineup

Bike	Size	Price	Top Tube	Wheels/Tire	Crank
Mach One Mini	Mini	$450	17″	20 x 1-1/8″	140mm
Mach One Junior	Junior	$450	18.5″	20 x 1-3/8″	152mm
Mach One Expert	Expert	$450	20.75″	20 x 1-3/8″	140mm
Speed Series Micro	Micro Mini	$795	16″	20 x 1-1/8″	127mm
Speed Series Mini	Mini	$795	17.5″	20 x 1-1/8″	135mm
Speed Series Junior	Junior	$795	18.5″	20 x 1-3/8″	135mm
Speed Series Expert	Expert	$795	19.5″	20 x 1-3/8″	165mm
Speed Series Expert XL	Expert XL	$795	20″	20 x 1.5″	165mm

Chase

Serious racers (and those with no budget), take note. Chase makes some of the nicest BMX race bikes around. This is the brand our son is currently riding on.

In addition to the complete bikes listed below, Chase also sells individual frames. Go this route if you’re interested in building up a bike from scratch.

Where To Buy: DansComp.com

Bike	Size	Price	Weight	Top Tube	Wheels/Tire	Crank
Edge Micro	Micro Mini	$699	15.4 lbs	16.25″	18 x 1″	130mm
Edge Mini	Mini	$699	16.7 lbs	17.25″	20 x 1-1/8″	140mm
Edge Junior	Junior	$699	17.5 lbs	18.75″	20 x 1-1/8″	155mm
Edge Expert	Expert	$699	18.6 lbs	19.75″	20 x 1-3/8″	165mm
Edge Expert XL	Expert XL	$729	19.5 lbs	20″	20 x 1.60″ F / 20 x 1.40″ R	170mm
Edge Element Expert	Expert	$1,399	18.4 lbs	20″	20 × 1-3/8″	165mm

Supercross

As a brand deeply embedded in the racing scene, Supercross BMX bikes are designed with performance in mind. The geometry of their frames is carefully crafted to optimize speed, control, and agility, making them a favorite among competitive racers.

If you are interested in building up a bike from the frame, check out Supercross. These frames aren’t cheap, but they do give you the option to create an amazing custom build.

Where To Buy: SuperCrossBMX.com

Frame	Size	Price
Vision Mini	Mini	$1,995
Vision Junior	Junior	$1,995
Vision Expert	Expert	$1,995
Vision Expert XL	Expert XL	$$1,995

Things To Know Before Buying

Wheel And Tire Size

Most kids BMX bikes have 20 inch wheels. The exception is the micro mini bikes which have 18 inch wheels. (And cruiser bikes which have 24 inch wheels).

Tire width is the other thing to consider. The skinnier the tires, the lighter they will be. Fatter tires, on the other hand, provide additional traction.

You want to consider the type of track your child will be racing on. Many tracks have concrete start hills and paved corners. In this case, you can get away with skinnier tires. If the track is entirely dirt, than you may want a little wider tire with more traction for the corners.

Top Tube Length

Not all bikes that are “Minis” will have the same top tube length. The longer the top tube length the further the reach and the bigger the bike will essentially feel.

This means that if your child is on the bottom end of a size range, look for a bike with a shorter top tube length. Or, if your kiddo is on the bigger end but not yet ready to size up, consider a bike with a longer top tube length.

It’s also worth mentioning that different riders may prefer different fits. Some kids will prefer to be more stretched out in a more aggressive position, while others may prefer to be more upright. Again, trying some loaner bikes before buying can be helpful for this.

Crank Length

We see way too many kids riding a bike with crank arms that are too long. This can rob your child of power as well as simply being unergenomic.

The best way to determine which size crank length your child needs is to measure their inseam. Even if the bike you are considering has the wrong size cranks, this is always something you can swap out on your own.

Rider Inseam	Appropriate Crank Length
16″	120mm
18″	130mm
20″	140mm
21″	145mm
22″	150mm
23″	155mm
24″	160mm
25″	165mm
26″	170mm

Gearing

BMX race bikes only have a single gear. This means that it needs to be the “right” gear, or your child will be spun out or struggling to turn over the pedals.

The good news is that you don’t need to worry about this too much when buying a bike, because you can always swap out the front or rear sprocket later. Still, most kids will want to run one of the combos below. (The first number is the number of teeth on the front chainring and the second number is the number of teeth on the rear cog).

44/16
39/14
36/13
33/12
25/9

Note that these are for 20″ wheels.

Weight

Remember, the heavier a bike is the more challenging it is going to be for your child to race on. The lighter the bike, the faster they’ll be able to go.

Of course, the lighter a bike, generally the more expensive the bike will be. In fact, serious racers will spend a lot of time and money upgrading components to build a bike as light as it can be.

Choose the lightest bike that is realistically within your budget.

Building a BMX Bike

If you are new to the sport, on a budget, or have limited bike mechanic experience, the easiest thing to do is to buy a complete bike like those listed above. That said, as your child progresses in their BMX career, there is a good chance that you’ll decide to build up a bike at some point.

Fortunately, BMX bikes are fairly simple and far easier to build that a mountain bike, for instance. You will need to buy a frame, fork, and components (wheels, handlebar, stem, chain and sprockets, pedals, saddle, etc….), but this can be a fun project to work on with your child.

Similarly, you can buy a stock bike and upgrade components as you go.

Buying A Used BMX Bike

The bad news is that kids grow out of bikes quickly. The good news is that this means someone is always selling their child’s bike.

We have had great luck buying our son used bikes. You can also find parts and components used if you’re thinking of building or upgrading a bike.

The best place to buy a used bike is at your local BMX track. Many people will bring bikes they are looking to sale to race or practice, and just throw a for sale sign on it.

Similarly, many BMX tracks have their own swap and sale Facebook pages. This is a great way to get a good deal.

More Stuff You Might Like

• A Parents Guide To Kids BMX Racing
• 7 Best Kids Full Face Helmets
• 5 Best Youth Bike Goggles
• Ultimate Guide To Indoor Bike Parks and BMX Tracks

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