FUBi: The most compact full-sized foldable bike in the world
FUBi: The most compact full-sized foldable bike in the world
FUBi is a titanium high-performance full-sized bicycle as well as an optimally compact foldable bicycle.
FUBi is a titanium high-performance full-sized bicycle as well as an optimally compact foldable bicycle. Read more
About this project
FUBi, the ultimate bicycle
FUBi is the world’s most compact, full-sized foldable bicycle that at the same time retains all the functionality and styling of standard full-sized bicycles! Our patented collapsible frame is the smallest in the world.
The bicycle is probably one of mankind’s more important inventions. It is the most energy-efficient means of transport there is. It is good for exercise and fresh air. And when it comes to moving oneself from one point to another it is the most environmental friendly way there is.
Apart from all the good sides with bicycles and cycling, bicycles have some pains and disadvantages related to it. Bicycle theft is one of these pains. So are bicycle storage, parking and transport. In addition to these major ones, there are others like maintenance, durability, functionality and so on.
The quest was therefore to find new, not before explored, ways to address these pains. All this effort has finally resulted in something very unique namely:
FUBi, the bicycle re-invented
FUBi has all the characteristics of a “regular” bike, and everything fits in a tennis bag (except the wheels) for easy carrying and easy storage, for example in a closet or a car’s trunk!
And FUBi is even more than that:
FUBi is foldable in two ways. One fast way and one optimally compact way.
FUBi is transformable.
FUBi is customer customizable.
FUBi is an easy “Do it yourself” bicycle kit.
FUBi has its very own new well-functioning FUBi fast-shift derailleur system.
FUBi has identical front and back wheels with extremely narrow hubs. And finally,
FUBi is a bicycle where the most important thing in a bicycle, the ride itself, has not been compromised therefore,
FUBi is a fast, safe and enjoyable-to-ride full-sized bicycle.
FUBi can in essence be used the same way as any other full-sized bicycles. All the different features characteristic of FUBi, like the two-ways fold-ability, are therefore added bonuses that can be used or not, according to one's needs! Therefore FUBi is not intrinsically an ordinary foldable bicycle. It is a full-sized bicycle with a fold-able feature! There is a difference there.
The FUBi features, or what makes FUBi so very different?
The FUBi optimum compact folding.
"Find a way to fold all the tubes of the frame as close and as parallel to each other as is at all possible."
This is the design mission statement that guided all of our engineering decisions. We reached our solution by finding a new way to fold a frame as close as possible and also at the same time by reducing the width of the frame.
The FUBi fast folding.
Fubi was designed to fold in several different ways and combinations to save you time. A fast fold can easily put FUBi in your trunk.
Shrinking the volume of Wheels and Hubs
FUBi operates the same way as a full-size bicycle, therefore the diameter of the wheels could not be reduced. So in FUBi, we shrank the width of the hub and eliminated the axis!
The FUBi hubs are quite narrow, only 50mm wide (2”) and therefore the volume of the FUBi wheel is reduced by as much as 60 to 75% (and two wheels will fit nicely in one hand)!
In addition, the front and back wheel are identical! There's no separate front wheel and separate back wheel. Either can go in any place, like on to a wall ;-)
The FUBi fast-shift derailleur
A totally new derailleur specifically suited for FUBi has been developed. Because the chain and cogwheel package / cassette are located on the outside of the chainstays, a traditional derailleur cannot even be used. The result is the extremely simple, very reliable and ”low normal” FUBi fast-shift derailleur (By a “low normal” derailleur is meant that the actuator spring moves the derailleur into the low gear position).
Low normal, high normal, same thing, same function, so what is the big difference?
In normal up and down shifting there is no significant difference between these two but because the FUBi fast-shift derailleur is a low normal derailleur the down shift will be realized by the actuator spring and not by the gear shifter wire as on a traditional high normal derailleurs. Therefore the speed of the down shift will be determined solely by how fast the chain will be able to climb or “move away” from the small sized high gear to the big sized low gear. This can be quite fast!
Given full slack on the shifter wire, the same as a direct to lowest gear on the gear shifter, the FUBi fast-shift derailleur will shift from highest to the lowest gear in well under one crank revolution!
Therefore FUBi is very well suited for city and town traffic where a fast down shift is often both required and desired due to frequent and unexpected stops and sudden slowdowns.
The FUBi Kit
FUBi is constructed in such a way that all assembly of a FUBi can be done using ordinary tools like spanners and Allen keys. No special bicycle tools are needed apart from maybe a crank removal tool.
As a FUBi consists of relatively many, and at the same time, simple, 2-dimensional parts, FUBi is therefore a meaningful, easy-to-assemble and above all, fun bicycle kit that anyone can do, even without prior experience in fixing bikes.
Also, all maintenance and repairs are easy to carry out using ordinary tools because of this design. All parts can be replaced easily.
wheels on FUBi are just wheels, as on a car, with no moving parts at all, the
main use of FUBi can easily be changed by changing the wheels. Also the wheels
have no expensive parts attached to them like cassettes or similar.
It is therefore possible to transform a FUBi from a road bike into city/dirt road bike and even into a MTB and vice versa.
In order to retain about the same outer diameter as the height of the tires varies, FUBi can accommodate three different sized rims, i.e. 622, 584 and 599 rims. FUBi can do this by having brake calipers that can easily be moved on the front fork and chain stay.
What has happened with FUBi so far?
The development of FUBi has been an understandingly long and very challenging journey. Here is a review of the development of FUBi so far starting with the very first prototype.
There were to begin with, two basic ideas that worked as the foundation for the development in order get a full-sized bicycle optimum compactly folded.
The first was a very narrow hub with no moving parts. This is a hub that can be called an inverted hub as the center of hub is rotating, whereas on a regular hub the axis is fixed and non rotating. The use of this hub resulted in a really significant reduction of the width of the frame, compared to a regular bicycle.
The second was the inverted head tube solution. On FUBi the front fork is rotating outside of the bearing assembly, whereas a regular fork rotates on the inside of the bearing assembly. The down and top tube ends are then attached to this head tube in an open-able way. This totally new solution is what made it possible to fold all the tubes of the frame more or less parallel to each other.
These two ideas together therefore made it possible to design a frame that could be folded very compactly, i.e. the very idea with FUBi. Otherwise the two first prototypes lacked practically all functionality you would expect from a decent bicycle such as torsional stiffness and a functioning derailleur.
In order to make FUBi into the present-day fully functional bicycle, the FUBi bicycle project has since then undergone the following phases of development and mainly focused on improving the functionality. Here are some of the more important ones shortly described.
- The drive-shaft connecting the cogwheel/ cassette/ freewheel to the hub. This drive shaft made the hub, bearing and cogwheel package, although outside the chain stay, into one strong unit.
- Loose free pivots. The FUBi frame is a so called truss frame, one that consists of triangles, thanks to the extra diagonal strut. In a truss frame all loads are only in the longitudinal direction of the elements. There are for example no moments at the end of the elements. Therefore pivots can be added without affecting the strength of the frame and the FUBi frame is in essence as strong as a regular frame.
- The structurally flexible bearing housing. All 8 deep groove bearings in FUBi are fitted into bearing housings of this type.
- A simplified bottom bracket. The bottom bracket bearings are fitted directly into the frame, with a simple straight crank axis through.Therefore no traditional bottom bracket cassette is needed!
- New improved head-tube/ bearing assembly. This new head-tube design improved the very bad torsional stiffness of the FUBi frame considerably. The head-tube, the down-tube, the top-tube, and the main tube now together forms an open-able and close-able moment carrying ring, giving the FUBi frame its good torsional stiffness.
- Quick-release/snap-on on chain stay /saddle stay connection and on diagonal strut connection.
- Part folding/ part dividable handlebar with bayonet fastening. This handlebar is as strong as an undivided handlebar and made the folding/ unfolding much faster and easier.
- FUBi in three different sizes. FUBi 25, FUBi 26 and FUBi 28. These have the exact same geometry and are only down or up scaled versions according to the differences in wheel sizes. This way functions quite well because we humans are just that, up and down scaled versions of each other.
- New design on H-type brake calipers that are movable on front fork/chain stay to accommodate different sized rims. This makes it possible to transform FUBi easily into different kind of bicycles.
- The FUBi fast-shift derailleur system. This is a low normal, index-able "flat" derailleur where the down shift, from highest to lowest can be accomplished in under one crank revolution!
In the development process many different ideas and many concepts have been tested in order to build a high performance bike and at the same time accomplish optimal compact folding. Several prototypes have been designed making improvements along the way until the present day fully-functional FUBi have finally emerged.
Also the testing of FUBi has been quite extensive under varying conditions, like winter summer, and by many different kinds of users. We have even tested things like bringing FUBi on the plane, fitting 8 FUBi in a car at once and storing FUBi in a railway locker and so on.
Our extensive testing lead us to realize that our original steel FUBi was way too heavy to carry at 15 kg! Reducing the weight therefore become imperative before we wanted to start production, thus the Carbon FUBi was born!
While carbon fiber reduced the weight to about 10 kg and made
FUBi a real joy to ride and both easy to carry and handle, we found some setbacks with carbon fiber.
Carbon fiber has no ductility, i.e. it will not deform before breaking, giving no warning. Carbon frames are very sensitive to pointed strikes that can give concealed damages to the structure and carbon frames have a limited lifetime. Inserting the required metal inserts into carbon fiber is difficult at best. Curing times and hand laying of fibers make the manufacturing process very slow therefore,
A Carbon FUBi would be very expensive!
The Titanium FUBi
We came to realize that titanium would be the ideal material of choice for FUBi. We would be able to achieve the same low weight as carbon fiber while gaining some unique properties that make it an excellent material for bicycle frame construction.
Titanium is as strong as steel yet, its density is almost half. Titanium will not rust or corrode, it won’t snap and it has excellent fatigue life. And as an added advantage with titanium, we can use the same methods and procedures we already have developed for the steel FUBi!
The titanium FUBi will weigh about 9.5 kg!
With titanium as the material of choice all the unique features of FUBi will come to their full right giving a bike that is strong, light and durable.
Therefore, our Kickstarter project is this:
To get Titanium FUBi into production.
This titanium FUBi project would include several steps.
The first one is to build a number
of Titanium FUBi prototypes, and test them in order to find the exact design we
then can proceed with. This would also include solving some of the remaining technical issues. Like eliminating the need for a separate spanner now needed for the folding/ unfolding of FUBi.
And reducing the time needed for folding even more by simplifying the folding process where it is still possible with the aim to come under 1.5 minutes for the compact folding and under 40 seconds for the fast folding.
The second step is to start the production of Titanium FUBi.
For this, new tools and new jigs are needed. We will adopt the same procedures and methods we have already developed for the steel FUBi and partly the carbon FUBi for titanium.
This also involves to a great degree, learning to fully understand and master all aspects of titanium production, where titanium welding is one of the more difficult and important ones.
As FUBi, like any bicycle, also consists of more or less regular bicycle parts, in addition to the parts we will fabricate, we also have to go through the process of choosing and/or ordering to our specifications the most suitable parts for FUBi, the ones that will make FUBi perform well and to stand out.
The titanium FUBi Kickstarter campaign.
In order to make FUBi into a really exciting experience and also as a way to make FUBi more affordable we offer FUBi as a kit, The FUBi Kit.
By following instructions, the FUBI Kit is an easy-to-do bicycle kit with a really great havingness where you among other things will be able to say that you yourself built your own unique FUBi.
And by following instructions, it is easy to build the the FUBi wheels yourself.
For those who want everything pre-assembled, we have a option for them too.
As FUBi is so compact and light we expect the delivery cost to be quite reasonable. Also when we have the number we need to ship to different locations, we will be able to negotiate good prices on the deliveries for you.
This is now your opportunity to be a part of the exciting FUBi bicycle project and more than just helping us, you'll be able to take advantage of this one-time only Kickstarter pricing on a Titanium FUBi. You have a chance to be among the very first to experience first hand, the awesome flexibility that FUBi offers, and you'll be able to say that YOU helped make FUBi into a reality.
Titanium FUBi specifications
FUBi will be available in two different sizes FUBi 25 titanium and FUBi 27 titanium.
FUBi 27 titanium geometry specs in mm:
FUBi 25 titanium geometry specs in mm:
FUBi Frame Specs
- Frame: FUBi collapsible frame consisting of 7 different frame parts, loose free pivots to accommodate folding and an extra diagonal part for stability, quick release on chain stay /saddle stay connection and on diagonal connection.
- Fork: FUBi fork with integrated head-tube.
- Head-tube: FUBi special and integrated with front fork by the bearing assembly.
- Bottom bracket: No traditional bottom bracket cassette! The bottom bracket bearings are directly fitted in the frame, with a straight crank axis through.
- Derailleur: FUBi Fast-Shift derailleur, 7 or 9 gears.
- Cassette: 13-28t, 11-34t, 7 or 9 gears
- Saddle: Open
- Post: Open
- Handlebars: FUBi crossing and dividable handlebar.
- Brakes: Rim brakes, FUBi H type brake calipers, movable on fork to accommodate different sized rims.
- Wheels FUBi 27: Rim 622, tire 23-622(700x23C), or rim 584, tire 35-584
- Wheels FUBi 25: Rim 571, tire 23-571(so called Triathlon size), or rim 559, tire 35-559
- Hubs: FUBi hubs and without moving parts, M12 R on the right side, M10L on the left side. 36 or 32 spokes.
- Crank set: Open, 48t or 52t chain ring
Specifications are subject to change. Which isn't a bad thing, as we will be looking for the best workable solutions and parts in order to make FUBi into a really cool experience.
Risks and challenges
Similar to many crowd funding projects, we face several risks and challenges in undertaking this next step in the evolution of FUBi . The primary risks for us include:
To achieve the level of functionality and simplicity in the user experience of FUBi that we have set as a goal, we have still some small engineering challenges we want to have solved in a more functional way. We have some ideas on how this can be done and we need to test them in order to find the right ones.
The second challenge is related to titanium as a material. With all the good properties of titanium that make it an excellent material for bicycle frames, it also has some challenging aspects related to it.
The most difficult one of these is titanium welding. Because titanium is a so-called reactive metal, extreme care has to be taken to keep the welded parts absolutely clean from impurities and also from gases like oxygen and nitrogen that react easily with titanium and thereby directly affects the quality of the weld.
We have made very extensive research concerning all aspects of titanium and especially titanium welding.
Therefore we have a plan on how to go about welding titanium to ensure a high quality weld at all times. This involves among other things, systems for complete inert gas welding environments. All these plans need to be implemented and in an efficient way.
We have taken some key steps to ensure our engineering success:
1) We have started to form a team of engineers and designers to complement the existing ones,
2) We have set out a plan for testing the Titanium FUBi so that it will perform according to our intentions and specifications.
Many crowd-funding campaigns can encounter problems when taking their prototypes to production. This includes issues like finding the right suppliers for the various parts and for the materials needed. Smooth execution is absolutely essential to overcoming such risks.
We have taken this vital step seriously and have therefore already established contact with a company that will handle this important part for us. They have through their network, contacts throughout the major regions of major suppliers of quality bicycle parts and related items.
THE FUBi TEAM
Finding the right people is a challenge for any endeavor. Success in this major step in the evolution of FUBi requires a team of talented, passionate, and motivated designers, engineers, and entrepreneurs.
We have already formed a truly dedicated base of people for this team, the FUBi Team, but because of the major undertaking, this means for us we are already actively looking for new members to join us.Learn about accountability on Kickstarter
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