Kids Dirt Bike & ATV Review 2026 | FRP 40cc Lineup Compared

Direct Answer

If your child has never operated anything motorized, start with the FA40-NEO — 13 mph ceiling, four wheels, and a key ignition you can keep in your pocket. If they already ride a bicycle confidently and you have flat open ground, the MB40 is the two-wheel entry point. If they're moving onto real trails with roots, ruts and small jumps, the FX40 Ogemaw is the only one in the lineup with full suspension and dual disc brakes. If the ground is rough or balance is the thing holding them back, the Sahara 40 quad handles it on four wheels with disc brakes at both ends.

The number everyone shops on is the number that tells you the least

Every one of these four machines is 40cc. Search "40cc kids dirt bike" and you'd assume you're looking at four versions of the same thing.

You aren't. Across four identical engine sizes:

• Top speed spans 13 mph to 20 mph — the fastest is 54% quicker than the slowest.
• Rider capacity spans 132 lb to 165 lb — a 25% spread.
• One has a single rear brake. Two have discs at both ends. One uses cables instead of discs.
• One has no suspension up front. One has full suspension at both ends.

Here is the part that surprised us when we laid our own spec sheets side by side: the ride with the highest weight capacity has the fewest brakes, and the ride with the best brakes has the lowest weight capacity. The MB40 carries 165 lb on a single rear disc. The FX40 stops on four-wheel — sorry, two-wheel — dual discs but tops out at 132 lb of rider.

Practically: if your kid is heavier and you ride hills, neither of those two is an automatic answer. That's the case where a quad — Sahara 40 or FA40-NEO, both 143 lb with brakes at both ends — is doing something the two-wheelers can't.

Full spec comparison

"Not published" means exactly that — we don't have a verified figure on our own spec sheet, so we're not going to invent one. Where a number is missing, the owner's manual on the product page is the source of truth.

MB40 — the two-wheel starting point

40cc 4-stroke, 18 mph, 165 lb rider capacity — the highest in the lineup, 16-mile range on a 0.65 L tank, rear disc brake, kill switch, 85% pre-assembled, EPA approved. Currently rated 4.41 from 87 owner reviews.

Who it's for: a kid roughly 6 and up who can already balance and pedal a bicycle without thinking about it. The automatic clutch means there is no shifting to learn — twist and go.

What we'd flag: one brake, at the back. On flat ground that's genuinely fine, and it's simpler for a beginner to modulate. On a downhill it isn't, because the front brake is the one doing most of the stopping on any two-wheeled vehicle. If your yard slopes, look at the FX40 or one of the quads instead. The 165 lb capacity is the reason this bike stays useful longer than the others as a kid grows.

Shop the MB40 →

MB40 in motion — see the full listing →

FX40 Ogemaw — the only real trail bike here

40cc 4-stroke, 20 mph, 132 lb rider capacity, 59 lb machine weight, full front and rear suspension, dual disc brakes front and rear, 2.5-10 off-road tires, 42″ × 11″ × 25″, 85% pre-assembled, EPA approved. Rated 4.6 from 82 owner reviews — the highest in the lineup.

Who it's for: roughly 8 to 13, already comfortable on two wheels, and actually going off the lawn. Suspension and brakes at both ends are what separate a dirt bike from a mini bike with knobby tires, and this is the only one of the four that has both.

What we'd flag: the 132 lb rider limit is the lowest of the four, which is counterintuitive for the model most likely to be bought for an older kid. A 12-year-old in the US is frequently already at 100–120 lb. Check the scale, not the birthday — if they're near the limit now, they'll be past it inside a year and the honest answer is to skip to the GMB100 instead.

FX40 Ogemaw on the trail — see the full listing →

Sahara 40 — four wheels, discs at both ends

40cc 4-stroke, 143 lb rider capacity, front and rear suspension, dual disc brakes front and rear, all-terrain ATV tires, ATV handlebars and padded seat, EPA approved.

Who it's for: a kid around 6 to 10 who either isn't confident balancing yet, or is riding ground rough enough that balance is the wrong problem to be solving. Four wheels remove the tip-over-at-a-standstill failure mode entirely, which is the single biggest source of early frustration on two wheels.

What we'd flag: our published spec sheet for the Sahara 40 is thinner than the other three — no verified top speed or range figure. That's on us, and we'd rather say so than fill the gap with a marketing number. If those two figures are decision-critical for you, the FA40-NEO is the quad with the complete sheet.

Shop the Sahara 40 →

FA40-NEO — the most controlled first ride

40cc 4-stroke OHV single-cylinder, 1.2 HP, 1.6 Nm @ 5,000 rpm, air-cooled. 13 mph top speed, 143 lb rider capacity, 83 lb machine weight, 19–31 mile range on a 1.8 L tank. 20.9″ seat height, 27.8″ wheelbase, 6.3″ ground clearance, 40.6″ × 22.8″ × 30.5″. Thumb throttle, front and rear cable brakes, front and rear suspension, 4.10-6 4-ply tires. Engine kill switch plus a key ignition.

Who it's for: the genuinely first-time rider, and the parent who wants the ceiling set low on purpose. 13 mph is slow enough to walk alongside. The thumb throttle is easier for small hands to modulate than a twist grip, and the key is the feature nobody talks about — the machine cannot be started while it's in your pocket. That's a real control, not a marketing line.

What we'd flag: cable brakes rather than discs. Cables stretch with use and need periodic adjustment — plan on checking them every few rides, and it's a five-minute job covered in the manual. The other tradeoff is the ceiling itself: at 13 mph, a confident kid will outgrow this faster than they'd outgrow the MB40.

Shop the FA40-NEO →

FA40-NEO in motion — see the full listing →

Which one, by rider

Four things that apply to all four

• They all pull start. A six-year-old usually cannot start one of these alone. Plan on being the one who yanks the cord, at least for the first season.
• Off-road and private property only. None of these is street legal anywhere in the US, and no amount of accessories makes a 40cc kids' machine road legal. Know where you're allowed to ride before the box arrives.
• Gear isn't optional. Helmet at minimum; gloves, boots and long sleeves for anything past the lawn. 13 mph onto gravel still takes skin off.
• Supervision is the actual safety feature. Kill switches and speed limits help, but the thing that prevents incidents is an adult standing there for the first dozen rides.

More on that last point: our full parent safety checklist for gas mini bikes, and if you want to size by height rather than age, the mini bike size chart by age, height and weight.

FAQ

What size dirt bike should I get for an 8-year-old?

Size by weight and inseam, not by birthday. At eight, most kids fit the FX40 Ogemaw (132 lb rider limit) or the MB40 (165 lb). The practical test is whether they can get both feet reasonably flat on the ground while seated — a kid on tiptoe will drop the bike at every stop and lose confidence fast. If they're already close to a model's weight limit, buy the next size up rather than replacing it in twelve months.

How fast does a 40cc kids dirt bike go?

It depends far more on the model than on the engine. Across FRP's four 40cc machines, top speed runs from 13 mph (FA40-NEO) to 18 mph (MB40) to 20 mph (FX40 Ogemaw). Actual speed varies with rider weight, terrain and tire pressure. Anyone quoting a single speed for "40cc" is guessing.

Does my child need to know how to ride a bicycle first?

For the two-wheelers, yes — the MB40 and FX40 both assume balance is already solved, because learning to balance and learning to manage a throttle at the same time is how beginners get hurt. The quads remove that requirement entirely: the Sahara 40 and FA40-NEO stay upright on their own, which is why they're the usual starting point for riders under about eight.

How much assembly is required out of the box?

The MB40 and FX40 Ogemaw ship 85% pre-assembled — typically the front wheel, front fork, fender and handlebars. Budget 30 to 60 minutes with basic hand tools, plus a fluids check before the first start. The quads require partial assembly; the exact steps are in each model's owner's manual, linked on its product page. If a machine is meant to be a surprise on a specific morning, unbox and assemble it a day early.

Are gas mini bikes and ATVs safe for a young kid?

They're as safe as the setup around them. All four have an engine kill switch; the FA40-NEO adds a removable key so it can't be started without you. What actually matters is a correctly fitted helmet, terrain matched to the rider's skill, a machine the child can hold up at a stop, and an adult present. Every FRP kids' machine is intended for supervised riding on private property.

When 40cc stops being enough

Every one of these tops out somewhere between 132 and 165 lb of rider. When your kid passes that — or when 20 mph stops feeling like anything — the next step in the lineup is the GMB100: 99cc-class 4-stroke OHV, 24 mph, 220 lb capacity, 30-mile range, 13″ SunF Chevron tires, EPA approved. It's the machine most FRP families end up on second, and plenty of adults ride it as their first.