The World’s Lightest Dirt Bike – Mountain Moto FX5

News -


The World's Lightest Dirt Bike – Mountain Moto FX5

A New Zealand company is about to launch the world’s lightest dirt bike – the Mountain Moto FX5, which will go on sale around the world this summer.

Mountain Moto FX5
Mountain Moto FX5

Built by FX Bikes the original idea was to combine a mountain bike and motorcycle parts to create a super lightweight motorcycle. The initial concept – the FX Mountain Moto – weighed in at 125lbs when it was first shown a few years back.

However, the final production-ready version – the FX5 – is slightly heavier than the initial concept at a mere 130lbs and in order to improve durability and performance the only mountain bike components that have been retained on the FX5 are the handlebars.

The Mountain Moto FX5's engine
The Mountain Moto FX5′s engine

The FX5 shares the same frame as a KTM 350, although FX Moto has lowered the ground clearance for its version. There is a choice of engines, either a four-stroke 125cc YX or Daytona-Japan engine. Customers will also be able to upgrade either engines to 190cc and FX says that it plans to also offer both manual and automatic gearboxes.


At such a low weight, the point of the FX is that owners will be able to easily carry the bike around in the back of vehicles or lift it over obstacles when off-road. They will also be able to take the bike into places where other, heavier motorcycles would not be able to go. There are plans later in the year to offer a road legal version too.

The Mountain Moto FX5 is light
The Mountain Moto FX5 is light

There will be three specifications (Steel, Gold, Titanium) for the FX5 when it goes on sale with prices starting at $3,995 and rising to $11,995, depending on which package is selected. Final specification and technical information is not available yet, as the bike is still in testing, but production is expected to start in Italy this summer.

For further information about availability and more details about the company go to:

  • MichaelEhrgott

    Thats a lot of money.

    • Jack McLovin

      Yes it is but plain mountain bikes cost as much. And by plain I mean carbon fiber frames hydraulic disc brakes and air suspension.

      • MichaelEhrgott

        Indeed. I just think of all the badass street-legal dirty bikes you can get for less than $4k. The kicker on something like this would be if it’s allowed on Mtn Biking trails. If thats the case then I would say its worth it. Won’t take long for California to classify these as OHVs though. Then it’s green stickers.

        • tbowdre

          no way this is allowed on hiking biking trails…. it has an engine

        • Piglet2010

          You might get by with a similar electrical dirtbike on MTB trails, particularly if you had auxiliary pedals, vintage moped style.

      • zedro

        yeah plain ones, top level downhill bikes go for 4 to 8K and the frequent complaint was “gee I could buy a dirt bike for that cost”. but they are also world cup level bikes that are sub 35 lbs. People forget how expensive ‘light’ is, and high end light weight heavy duty bike parts are horribly expensive….front forks alone can top 2K.

        • runnermatt

          Cheap, Light, Strong: Pick two.

  • PattonStrength

    Sent this to a buddy of mine who is into MB’ing and wants to start trail riding, dirt biking, etc. I think the fact that it is so light and non-threatening looking is pretty appealing for the crossover set.

  • Justin Henry

    looks cool… i’ll take one.

  • DrLove

    “The FX5 shares the same frame as a KTM 350″… No. It shares some of the geometry as the Freeride (wheelbase, rider triangle).

  • Kr Tong

    My first thought was, “so light, how do you have to worry about keeping weight over the front?” Then i saw the risers stemmed out past the triple. Very fun. very cool exercise in design and engineering.

  • Vincent T.

    Really reminds me of the MotoPeds bikes, which are a fraction of the cost for very similar capabilities. Cool though.

  • phoebegoesvroom


  • zedro

    odd that the fork is called the Monster with 40mm stanchions, which used to be a bike fork made by Marzocchi known to be the burliest (read unnecessary) fork made in the 90s (it was said t be based on a trials fork at the time).

    • vwaters

      Marzocchi also made a super monster with 12 inches of travel to the monster’s 8 inches of travel (read super unnecessary), and both were the heaviest forks ever made by Marzocchi. The Monster T and its 12 pounds of glory is dated, but sounds like an easy prototype for them. In the mountain biking world, this was just a failed motocross fork crossover. Perfect for this project.

      I think that a fork with more modern materials could easily shave a few pounds and be similarly as strong… Or still be 12 pounds and stronger! This thing is bound to take some abuse.

      • zedro

        Fox made a 40mm stanchion fork that looked the part but much lighter, problem is the material got pretty thin to keep the weight down, and think it had tapered everything and cost a fortune ( not sure what they’re up to now, haven’t looked in a long time). I remember the Super Monster, think it was made for that Bender guy to do the rediculous drops to flat (I.e. no finess landings, pre-Redbull rampage) and ended up as a limited run production. It might of been offered for 80cc bikes, or at least it should of. Never heard of anyone breaking those forks, your bike would fold with your spine before that.

  • Versys Jake

    Or just pick up a mini bike: xr100, ttr125, cr80 or trials bike… they weigh about 160lbs. 30 pounds more and you have a fully capable dirtbike. Seems a little silly to have some clunky one-off with expensive replacement parts.

  • eddi

    Speaking of second bikes, a street-legal version of this would be fun. A bike that’s about half my weight and liftable. Their largest engine and some suspension work as long as I’m daydreaming.

  • Stuki

    And that’s with a 4 stroke…..
    115lbs with a 100cc smoker……..!

    The weight lowering obsession does seem to have created a bike that’s only really useful for tooling around on. Not much room for gas, nor for any kind of luggage. And even if one could find a way to jerryrig something, it would negate most of the purpose of the lightness to begin with. And, while NZ is likely different, here in the land of the fenced in, even someone strong enough to lift her bike over a barbed wire fence; still ain’t bullet proof…..

    For tooling around, however, it looks absolutely awesome. I wanted to stand up and cheer when the guy in the video said “it encourages you to try stuff you simply wouldn’t dare on a heavier bike” or some such, before progressing to barrel into some gigantic, slippery tractor tires, and only sorta kinda making it across…… I bet the feeling of invincibility is akin to riding a mountain bike in full MX gear; without all the sweating and clumsiness.

  • markbvt

    Oooh… they’re making a dual-sport version. Want!

  • Justin McClintock

    I’ll take it in street legal with the big motor. Ultimate playtoy, and you don’t even have to trailer it to the trails!

  • JT

    LOL this thing is a broken bones factory! The number of people who will be doing things beyond their skill level and suffering will be huge. That being said, still looks like crazy fun. When we were kids we all had 125 enduros and would thrash them all sorts of ways. This bike looks to be something similar.

  • JD

    So im going to pay 4 grand to see a moped engine on a mountain bike? no thanks. i can build that in my shed for a couple hundred bucks