iruka - A Mobile Transforming Bike

coming soon


Transform. Run. Wait. Walk. Sleep.

iruka is a mobile transforming bike that changes its form into four modes to suit the scene. It transforms in seconds without any tools, and it extends mobility.

Faster than the wind.

Smaller the wheels the slower? Not for iruka. The traveling distance of one pedal rotation of iruka in top gear is 6.9m - which makes 18-inch wheeled iruka almost 1.5 times faster than 26-inch wheeled average city bike. The accurate gear ratio, high rigid frame, appropriate geometry changes your pedaling into driving force efficiently, and it assures you outstanding speed experience.

Optimized to be zippy.

Agility and flexibility is key when riding in cities, as well as speed. Take Chiyoda ward, a small district in the center of Tokyo. It’s only 12 square km but has 30m difference in elevation, over 100 thousand cars are traveling daily through hundreds of traffic lights. It sure is busy, but with iruka you need not worry. The 18-inch wheel manages frequent starts-and-stops well, Shimano Alfine 8 speed hub makes it widely-capable from high-speed cruising to steep climbing, and the small rotor disc brake works lightly and steadily.

Compact for impact.

iruka can be folded 30% smaller than the ordinary folding bikes*. The perfect rectangle folding shape fits in a car trunk, train seat, under your desk, or any other space. Also, it settles in a narrower space when placed vertically.

*compared to a 20-inch folding bike’s volume (W x H x D)

Rolls to follow you.

Even if it can be folded compactly, isn’t it a burden to carry a bike? Indeed, but not iruka. The front and the rear wheel of iruka are folded parallel and coaxial, which you can roll to carry iruka easily like a carry cart. A metro concourse, airport lobby, office building hallway, iruka will follow you wherever you go.

Park smart.

No kickstand? No worries. When you fold the rear wheel, iruka’s rear fork works as a kickstand. The length becomes 2/3 its size, so you only need half the parking space of the other bicycles. With iruka, parking has never been more clever.

Carry whatever you please.

Do you prefer to bike even if you have a lot to carry? The front basket or rear carrier wouldn’t be the best solution. It may be fixed, not be the right size, and probably not so cool. iruka takes a new approach with it’s three unique attachments that utilize the small wheeled bike specific spaces.


2018.10.04 iruka T8, production sample released. The mass-production shipment will be aound the end of 2018.
2018.04.05 iruka T7.1 is available for test ride at LORO Setagaya April 14 and 15.
2018.03.29 iruka exhibits T7.1 at Minivelo Touring Festival in Shimanami Kaido Vol.4 May 19 and 20.
2018.03.13 Design registration of iruka's frame officially certificated.
2017.11.15 English teaser site launch.
2017.08.25 Japanese teaser site launch.
2017.08.24 iruka’s frame structure applies for patent and design registration.
2017.06.10 iruka T7.0, final beta model released.

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Frame material 6061 aluminium
Wheel size 18-inch
Gearbox Shimano Alfine 8S(internal 8 speed)
Braking system Mecanical disc brake
Size when folded W79cm x H48cm x D35cm
Carrier attachments
iruCart - Detachable compact trailer (also available as a carry cart)
iruCarry - Detachable suspending rear carrier
iruCatch - Detachable bag holder
Release/Price End of 2018/Around 200,000JPY(subject to change)


Masaki Mark Kobayashi
Founder and President, iruka Inc.


In 2004, I decided to buy a bike after I moved to a new home. Without any specific plans of what kind of bike to get, I went to a bike shop in Akasaka where a friend worked at. The section for folding bikes caught my attention.

It was the first time for me to take a good look at folding bikes. Brand “D” from Taiwan, “R” from Germany, and “B” from England - I realized that folding mechanisms differed for each brands.

I took a few for test rides, and realized my assumption that small wheeled folding bikes were slow. It was much faster than expected. I found that it was good enough for commute. That it could be carried into the office. That it could be carried by car or even on a train. It was like a transforming robot. It didn’t take me a minute to decide I would buy one.

I chose brand D’s bike because the riding posture suited me the best. It had 20-inch wheels, 9 speed, which could be folded sideways in half. It was approximately 100,000JPY, which was not cheap, but I wanted a ride as soon as possible.

Luckily the mechanic was available that day, so it could be set up for me to ride back home the same day. A couple of hours later, I pedaled out to Tokyo city in the twilight.

From Akasaka Mitsuke, up Kinokuni ramp and through Yotsuya, when I pedaled in top gear on the congested Sotobori Street, the cars that caught in traffic beside me faded behind. It was quite exciting and pleasant. Looking back, it was the day that has changed my life.

The best and the fastest

From the next week, I switched to biking from my 30-minute commute by train. There was no parking space in the office building, but it was safe from theft or removal by folding and taking the bike into the office regardless.

My route to work was 5km, and I assumed that it would take longer than taking the train. However, once I started my new commute, I found out that it took slightly shorter. The train ride itself took less time, but biking was faster from door to door. It was a great discovery.

Later, I learned that there were many studies and data that proved biking was the fastest means of transport within 5km in distance. The 5km radius of central Tokyo almost encircles all of Yamanote Line. It would not be an overstatement to say that biking is the fastest ride in central Tokyo.

It was not just the speed, but biking itself was what fascinated me. Biking in Tokyo made me realize the many delicate and rich aspects of the city that I could not notice by train or drive. The dull commute to work became a special, anticipated time of the day. Biking changed the time I used to travel into an exciting one, or even a deep, quiet time of contemplation.

It wasn’t long before I started biking everywhere in the city, or folded my bike and traveled on trains and cars for cycling excursions out of Tokyo. Traveling in Tohoku, Shimanami Kaido, Shonan, and Kyoto etc. - the amazing trips wouldn’t have been the same without my bike.

Fast and fun. Plus, by folding my bike I can utilize other means of transportation to cover for the particular weakness of biking; long distances, elevated travel, or bad weather. What an amazing vehicle folding bikes are. By partnering with a folding bike as a use of transportation I had gained a new lifestyle.

Searching for the ideal

I really fell in love with brand D’s bike. It ran well, its solid and sharp looks were also quite appealing. It weighed precisely 10kgs, making it light for its kind. It was indeed a great bike.

However, as I continued to use it, I realized that there were some flaws, and I could not say that I was perfectly satisfied. To name a few, it couldn’t be stored under my office desk. It could only fit at the very back of the compartment on a Shinkansen. These issue were related to the size and shape when folded. Furthermore, 10kgs also became a burden to carry from the entrance of the office building to my desk or from the ticket gate to the platform of the station.

Roadability was not an issue for the regular city ride, but when I pedaled for speed or climbing, the frame rigidity felt a little flexy. Most of folding bikes, including brand D, positioned the hinge on the top tube, which was the spine of bike. Heavy pedaling force around the bottom bracket caused twisting and creaking.

The German R’s bike didn’t have a hinge on the top tube and had better frame rigidity, but the folded size was almost the same as D’s. British B’s bike fit within 60-cm square which was more portable than D’s or R’s, but I was not comfortable with the riding position and roadability. There are many other folding bikes out there, but considering performance and portability, D, R, and B are the world’s top three in name and reality. In other words, there was no existing folding bike that I would be 100% satisfied with. That did not mean that I wanted to create my own, at least, until the summer of 2006.

Decision to start my own

In 2006, I was working at an Internet advertising agency as a CFO. The company was founded by 4 members including myself in our 20’s. It was listed to JASDAQ in 2004, and had an annual revenue of 30 billion JPY, with over 500 employees at that time. For a company that started from a small apartment by youngsters, I would say that we were quite successful. The company was growing and I was busy and fulfilled. On the other hand, I had no intention to cling onto my position, and I would have left the company any day if I had found another passion for life.

That summer, the management team held an off-site meeting. One of the items on the agenda was to share our individual passions to understand each other better. The day before, I sat in front of my PC at home to make a resume. What were my dreams? I typed my thoughts into the text editor. About the company, my hobbies tennis and bodyboarding, then a thought ran across my mind.

  • Start my own folding bike brand

The moment I hit the enter key, many thoughts connected into one vision.

  • A world where bikes are preferred over cars would be a happier place.
  • Folding bikes are fun; I wonder how it could be more popular.
  • There are good folding bikes, but there could be better.
  • Could I start and manage a business for the global market?
  • How would I do if I started a new business from scratch with my present knowledge and experience?

My random thoughts came together. “I am starting my own company. I am going to make an amazing folding bike for the world market. I am going to spread the biking lifestyle to the world and make everyone happy.” It was all quite sudden, but it took me away.

Sommelier knife

Next year, while I was preparing to leave the company I was working at, I started discussing the requirements for iruka’s design with a product designer I had found on Google.

  • Mainly for city rides, but also good for middle and long distance.
  • Readily portable indoors and in-vehicles.
  • Easy to carry when folded.
  • Realize both roadability and portability with as little parts as possible.
  • To be able to bike even with much to carry.
  • Something precious to keep close and own.

This meant the bike must have high performance like a sports bike, must also be much easier to carry than the other folding bikes, must be expandable for carrying attachments, yet simple and beautiful in form. Performance and portability is generally considered a trade off. The wheel size and the wheel base (the distance of the front and rear axles) make it a challenge. An extremely small pair of wheels and shorter wheel base can make a smaller bike, but that would sacrifice the performance.

Striking a balance of performance and portability meant the geometry no different from sports bike, with 18-inch wheels or more, no hinge on the top tube, which can also be compactly folded, and with a devise to carry easily - it required a revolutionary folding mechanism. We brainstormed and sketched continuously for almost one year, but couldn’t come up with a good idea.

It was around the year end, when I attended a friend’s wedding reception. I came across a sommelier knife (folding wine opener), that a staff had in hand. The knife, lever, and the screw - all the tools fit under the handle smartly. The slit in the center of the handle and its arch shape made it possible. An idea struck me.

After the enlightenment, I sketched the basic structure of iruka frame behind a sickness bag on the plane on my way to India for the year-end holidays. It was the archetype of the jack knife frame of iruka.

Production partner

In 2008, I left my previous company and founded iruka Inc.. After I spent dozen months to design the basic structure of the product, I started visiting OEM factories in Taiwan and China to look for a partner to create the prototypes and handle mass production.

Japan was previously one of the largest bike producing nations, but most manufacturers lost to the price competition against other countries and went out of business; mass production was absolutely difficult in Japan. Instead, Taiwan and China are now the leading nations in bike manufacturing. Today, most famous European and American bike brands also have OEM in Taiwan and China.

Finding a partner was not as easy, at all. Almost all factories showed the positive responses to the product, but when it came to actual business, they didn’t wish to proceed. There were multiple reasons, but the most important reason was that the project was high-risk and uncertain for them. We needed to develop a brand new structure and parts from scratch, of which estimated a sizable investment of time and labor.

Also, we only had the drawings, and we did not have the product in hand. Ironically, to proceed to production, it’s much smoother with the actual product to touch and discuss. And, without any pieces in hand, they were not sure of my seriousness and commitment.

For such reasons, I ordered a skeleton model at a small workshop in Japan, which I then took to Taiwan and China. After a number of visits, a manufacturer close to Shanghai said they would take the project. However, after creating the first prototype, the GM at the factory left and the project suffered a setback.

After that, we had to continue our long journey of finding a production partner. Several manufacturers gave up after creating one or half a prototype. The iruka’s production was still challenging and maybe they couldn’t deal with our uncompromising attitude. Everytime we lost a manufacturer, we had to seek anew.

The birth

While we traveled from factory to factory, iruka’s design changed significantly by generations of the prototype. The structure of the front fork, the folding mechanism of the stem, the lock functions, the way of manufacturing of the top tube, the layout of the wiring - almost everything was revised from the original plan for the better. Even if the drawings and 3D renderings appeared perfect, it proved wrong or inspired a better plan when it was put to light and tested. At the same time, we started developing the carrier attachments, which helped us collect feedback for the bike. There was so much we learned only after creation.

It was an exciting process, but of course the prototyping was not our goal. In the winter of 2015, when we were anticipating to fix the details at the next prototype to go for the mass production, we met company “J” that had a factory in midland Taiwan. J was a small but unique company, creating original bikes mainly folding ones. J’s president who was also an excellent engineer expressed his strong interest in iruka, and offered to take over the creation of test models as well as mass production. His knowledge and experience took iruka to another level. After two test models, iruka is finally ready to start mass production.

Now, iruka is waiting to be your partner.


Company name iruka Inc.
Representative Founder and President
Masaki Mark Kobayashi

Born in Shizuoka. Graduate of Keio University Faculty of Business and Commerce. Started his career at Mori Building, and left as one of the founding members of Opt Inc.. Mainly led the administrative department as a Director and CFO.
Loves Tennis, Cooking, Music, Bodyboarding and Sumire (Miniature Shiba-dog)
Twitter @masakikoba
Blog "iruka's picture diary"

Address 3-18-6 #211 Jingumae, Shibuya-Ku Tokyo 150-0001
Capital 50million JPY
Mission To make the world and people happier through bikes.
Vision A world where biking is considered cooler than riding a Mercedes would be slightly different from now.
Origin of the name iruka, means dolphin in Japanese, as a symbol of freedom, intelligence and agility.
Biking around the city freely and zippy, just like a dolphin would slide the boundless ocean.
Origin of the logo

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