7 Best Kids BMX Race Bikes (Micro Mini, 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.

Micro Mini<53’6″-4’0″
Expert XL10-135’3-5’7″

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 Swift Expert

DK makes great BMX race bikes and they are (relatively) affordable which makes them attractive for families just looking to try out the sport. (This is the brand that MY son rides, so I might be a bit biased).

They have two different models across sizes–the Swift and the Sprinter. The latter is $100 more but has upgraded components and comes in a little lighter.

DK Lineup

BikeSizePriceWeightTop TubeWheels/TireCrank
Swift MicroMicro Mini$35016.3 lbs16.25″18 x 1”120mm
Swift MiniMini$35016.3 lbs17.25″20 x 1-1/8”140mm
Swift JuniorJunior$35017.3 lbs18.25″20 x 1-3/8”155mm
Swift ExpertExpert$35020 lbs19.5”20 x 1-3/8”165mm
Sprinter MicroMicro Mini$45015.9 lbs16.25″18 x 1”120mm
Sprinter MiniMini$45016.1 lbs17.25″20 x 1-1/8”140mm
Sprinter JuniorJunior$45017.1 lbs18.25″20 x 1-3/8”155mm
Sprinter ExpertExpert$45018.5 lbs19.5”20 x 1-3/8”165mm


GT Speed Series Junior

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.

GT Lineup

BikeSizePriceTop TubeWheels/TireCrank
Mach One MiniMini$42517″20 x 1-1/8″140mm
Mach One JuniorJunior$42518.5″20 x 1-3/8″152mm
Mach One ExpertExpert$42520.75″20 x 1-3/8″140mm
Speed Series MicroMicro Mini$79516″20 x 1-1/8″127mm
Speed Series MiniMini$79517.5″20 x 1-1/8″135mm
Speed Series JuniorJunior$79518.5″20 x 1-3/8″135mm
Speed Series ExpertExpert$79519.5″20 x 1-3/8″165mm
Speed Series Expert XLExpert XL$79520″20 x 1.5″165mm


Haro Mini

Haro is well known for their freestyle and street BMX bikes, but they make great race bikes as well. Most of these bikes have a v-brake, but the Expert XL even offers a rear mechanical disc brake.

BikeSizePriceWeightTop TubeWheels/TireCrank
Annex Micro MiniMicro Mini$43915 lbs16.75″18 x 1″130mm
Annex MiniMini$43916 lbs17.75″20 x 1 1/8″145mm
Annex JuniorJunior$43916.7 lbs18.3″20 x 1 1/8″155mm
Annex ExpertExpert$43916.9 lbs18.87″20×1 3/8″170mm
Micro MiniMicro Mini$54915.5 lbs16.75″18 x 1″130mm
MiniMini$54915.7 lbs17.6″20×1 1/8″130mm
JuniorJunior$54916.3 lbs18.3″20×1 1/8″145mm
ExpertExpert$54916.8 lbs18.87″20×1 3/8″155mm
Expert XLExpert XL$61919.4 lbs20″20×1.65 F/ 20×1.50 R170mm


Redline is one of THE original names in BMX. Like most of the other brands listed here, Redline offers two product lines: the entry-level MX and the higher-end Proline.

BikeSizePriceTop TubeWheels/TireCrank
MX MiniMini$45018″20 x 1-1/8″140mm
MX JuniorJunior$45018.5″20 x 1-1/8″155mm
MX Expert XLExpert XL$45020″(F) 20 x 1.6″ / (R) 20 x 1.4″170mm
Proline MicroMicro$48016.5″18 x 1″130mm
Proline MiniMini$56017.5″20 x 1-1/8″140mm
Proline JuniorJunior18.5″20 x 1-1/8″155mm
Proline Expert Expert$63019.5″20 x 1-3/8″165mm
Proline Expert XLExpert XL$63020″20 x 1.60″170mm


Jet Accelerator Mini

Jet offers simple, entry-level race bikes. This is a UK company, but you can get their bikes in the US via SourceBMX.

BikeSizePriceTop TubeWheels/TireCrank
Accelerator MiniMini$33917.5″1-1/8”140mm
Accelerator JuniorJunior $33918.5″1-1/8”150mm
Accelerator ExpertExpert$33919.75″1-3/8”160mm


Chase Edge Micro

Serious racers (and those with no budget), take note. Chase makes some of the nicest BMX race bikes around.

BikeSizeWeightTop TubeWheels/TireCrank
Edge MicroMicro Mini15.4 lbs16.25″18 x 1″130mm
Edge MiniMini16.7 lbs17.25″20 x 1-1/8″140mm
Edge JuniorJunior17.5 lbs18.75″20 x 1-1/8″155mm
Edge ExpertExpert18.6 lbs19.75″20 x 1-3/8″165mm
Edge Expert XLExpert XL19.5 lbs20″20 x 1.60″ F / 20 x 1.40″ R170mm
Edge Element ExpertExpert18.4 lbs20″20 × 1-3/8″165mm


Supercross Envy Frame

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.

Envy MicroMicro Mini$650+
Envy MiniMini$650+
Envy JuniorJunior$650+
Envy Expert Expert$650+
Envy Expert XLExpert XL$650+

Things To Know Before Buying

kids bmx race bikes

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 InseamAppropriate Crank Length


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).


Note that these are for 20″ wheels.


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.

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2 thoughts on “7 Best Kids BMX Race Bikes (Micro Mini, Mini, Junior, Expert)”

    • U can swap 18 inch wheels onto a gt Mach 1 16 inch by slightly grinding front fork for clearance and running a road bike brake caliper to make an 18 inch micro wit a 15is inch top tube @troygreenebmx on ig and look back to around 2018/early 2019 for pictures of one black red and green bike, hope this helps


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