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FRP FX Series
Gas Dirt Bikes & Pit Bikes
Three dirt bikes. 40cc to 140cc.
Top speed · FX40 20 · FX125 56 · FX140 65
Explore the lineup
Three dirt bikes. Pick your start.
Take a closer look.
The FX125 in motion — the clutch, the suspension, and real trail riding.
Why Choose FRP Dirt Bikes.
Buy with confidence
Backed after the sale.
Every FX comes with a 1-year warranty, a 60-day return window, and fast US-based support.
1-Year Warranty60-Day ReturnsUS-Based SupportShips from the USA
Ways to pay
Pay over time.
Split any bike into four interest-free payments at checkout with Afterpay. Ride now, pay it off over six weeks — no added cost.
4 Interest-Free PaymentsNo Hidden Fees
Afterpay
4 interest-free payments · 0% interest
Ride together
Ride with the crew.
There’s a whole Discord of FRP riders across the US — swapping trails, builds, and meetups. Get an FRP and you’re not just buying a bike, you’re rolling with a crew.
US-Wide CrewTrails & MeetupsBuild Talk
Side by side
Pick the right bike.
Swipe to compare →
| FX140New | FX125New | FX40Starter | |
|---|---|---|---|
 |  |  | |
| Best for | Riding for real | Learning to shift | Learning to ride |
| Rider | Teens & adults | Teens & adults | Kids 6–12 |
| Engine | 140cc oil-cooled | 125cc air-cooled | 40cc 4-stroke |
| Power | 11.0 hp | 8.7 hp | — |
| Torque | 10.2 N·m | 8.8 N·m | — |
| Seat height | 33.9" | 28.1" or 33.9" | — |
| Max gradient | 30° | 28° | — |
| Top speed | ~65 mph | ~56 mph | 20 mph |
| Transmission | 4-speed manual | 4-speed manual | Automatic |
| Brakes | Hydraulic disc | Hydraulic disc | Dual disc |
| Suspension | Front & rear | Front & rear | Full F & R |
| Start | Electric + kick | Electric + kick | Easy pull start |
| Wheels | 17"/14" | 14"/12" or 17"/14" | Mini |
| Max load | 265 lb | 265 lb | 132 lb |
| Price | From $1,149.99 | From $799.99 | From $279.99 |
| Shop FX140 | Shop FX125 | Shop FX40 |
Questions, answered
Before you buy.
How fast is a 125cc dirt bike?
The FX125 tops out around 56 mph and the FX140 hits about 65 mph — real speed depends on rider weight, gearing and terrain. More on how cc translates to top speed.
What size dirt bike for a 12 year old?
Around 12, most riders fit the FX125 in the smaller 14"/12" size (28.1" seat). Match height and inseam with our dirt bike size chart by age, or see the best dirt bikes for 12-year-olds.
What’s the weight limit on a dirt bike?
The FX125 and FX140 both hold up to 265 lb, so they carry teens through adults; the FX40 is rated to 132 lb. Full breakdown of dirt bike weight limits.
FX125 vs FX140 — which should I choose?
In the 17/14 build they share a chassis — same 33.9" seat, same 49.2" wheelbase, same 265 lb load. The difference is the engine: the FX125 is air-cooled, 8.7 hp / 8.8 N·m, rated to climb 28°; the FX140 is oil-cooled, 11.0 hp / 10.2 N·m, rated to 30°. Oil cooling holds that power up on long climbs, hot days, and hour-long sessions, where an air-cooled engine starts to fade. For short sessions in the yard, cooler weather, or a lighter rider, the FX125 is enough. We break it down in the 125cc vs 140cc dirt bike guide.
What size dirt bike for a teenager?
A taller teen fits the FX125 in the 17"/14" build (33.9" seat) or steps up to the FX140. See what size dirt bike for a teenager.
Are FRP dirt bikes street legal?
No — FRP dirt bikes are EPA off-road models, not registered for public roads. Ride them on private property, trails and off-road areas (the FX40 and FX140 are not sold in California). More on whether a dirt bike is street legal.
Do FRP dirt bikes need 2-stroke oil mixing?
No — every FRP FX is a four-stroke, so there is no fuel-and-oil premixing. See how to choose the right engine oil.
Trusted by 865+ verified buyers
Built around what riders ask.
A Zongshen® engine, not a no-name
The FX125 runs a Zongshen four-stroke — built by one of the world's oldest and largest engine makers. Decades of proven reliability, parts everywhere, and far fewer breakdowns than the no-brand engines in cheaper bikes.
Holds real weight
The question buyers ask most is how much a bike can carry. The FX125 is built for a 265 lb max load — so it fits a growing teen or a full-grown adult, not just a small kid.
Fits the rider
The other thing everyone asks: will it fit? The FX125 comes in two wheel sizes with a 28–34" seat, so one bike suits a younger rider or a taller adult — and the FX40 starts the little ones safely at 20 mph.
Grow with the rider
Start the journey
Pick the step that fits today. The next one will be waiting when they're ready.
