N55's spaceframe tricycle can be built at home from plans


September 17, 2012

XYZ Spaceframe Vehicles – this one shown with a trailer – incorporate weather-resistant and lightweight frames that are made using standard aluminum tubes

XYZ Spaceframe Vehicles – this one shown with a trailer – incorporate weather-resistant and lightweight frames that are made using standard aluminum tubes

Image Gallery (21 images)

Danish design studio N55, in collaboration with German designer Till Wolfer, has created a series of open-source human-powered vehicle designs that can be built at home using basic tools and materials. Dubbed XYZ Spaceframe Vehicles, the models incorporate weather-resistant and lightweight frames that are made using standard aluminum tubes. Those tubes are assembled using simple stainless steel bolts, washers and nuts. “Unlike the singular load-bearing tube seen in traditional bike structures, the main structure is an orthogonal spaceframe of standard aluminum tubes,” says N55.

The vehicle designs consciously use aluminum with its advantageous strength to weight ratio for the cost. Due to its natural ability to resist corrosion by protecting its own surface with aluminum oxide, the metal is also naturally weather-resistant and thus the use of chemical surface treatments can be avoided.

The XYZ Spaceframe Vehicle construction plans include a single- or double-seated model and a cargo version that’s suitable for loading up and transporting the groceries. The plans position the wheels and chains within the frame and at a distance from the rider. The recumbent rider is also positioned at a comfortable height, without putting unnecessary stress on their legs. Self-greasing plastic washers are used for the steering components, and the exposed ends of the tubes are capped with a standard plastic PE plug, preventing any nasty sharp corners.

All other parts such as wheels, pedals, and seats are standard features that can be commonly acquired from hardware stores or bicycle shops. Furthermore, the models can be easily upgraded with the addition of a cover to improve wind resistance, or even with an electric motor to aid in longer journeys.

The project reflects N55’s goal of creating a greener environment and lifestyle, and thus the XYZ Spaceframe Vehicle plans can be downloaded free of charge from its website. The studio also encourages the development of small human powered vehicle factories within local communities, to further encourage the use of non-fossil fueled vehicles.

Ed's note, September 18: This article originally repeated N55's claims that aluminum is three times stronger than steel. This is not the case.

Source: N55

About the Author
Bridget Borgobello Bridget is an experienced freelance writer, presenter and performer with a keen eye for innovative design and a passion for green technology. Australian born, Bridget currently resides in Rome and when not scribbling for Gizmag, she spends her time developing new web series content and independent cinema. All articles by Bridget Borgobello

That is awesome, in the US this would be illegal to drive on roads, sidewalks or most any public land. WOW super awesome, I could make this and drive up and down my drive way. Totally worth it.

Michael Mantion

I am unsure of what portion Michael is from but where I live it is legal. 3 wheels or less and under 100 lbs and its classified as a bicycle. Add power under 49ccs or 1500W and your an unlicensed moped.

Bryant Drake

Love it! I'm getting excited already, just have to get the materials sourced and we're away!

Thanks to all at N55... :-)


Aluminum is not three times the strength of steel and many if not all of the high strength aluminum alloys don't do the self coating thing.


In most of Europe this would be classified as a bicycle. If you use a rear wheel with an electric motor, than the requirements is max 250W, no assist above 20 km/h, and the pedals have to be moving to get power assist.

I really did like the simplicity and the use of standard parts. Also that the chain and drive system is kept away from the driver. The cargo system would also be interesting, seems it should be able to carry a good load. The seat seems to be more stylistic than practical, unless there is some kind of moulded seat you are likely to skid around a bit. I would also think that the version with a short wheelbase migh be a bit nervous on the road, though that might be an advantage in cities. Fully equipped I think it will be difficult to come very much below 50 pounds on this bike. Just the bolts should be a couple of pounds...

Still, this is one of the most "buildable" designs I have seen so far...


This is astonishingly bad structural engineering. Bucky Fuller spins in his grave at the effrontery of calling this "space frame". Instead of using the natural strength of triangulation, this configuration depends on the strength of the bolts and joints for whatever feeble rigidity it has. Check out some real recumbents like Rans or Easy Racers for efficient use of materials.

Clark Brooks

What a crock! A proper space frame is fully triangulated. Structurally, this is just a mess. However, all aluminum alloys do develop a tight oxide layer, rather than flaky rust.

Bob Stuart

Bill Allison, the lifelong suspension engineer who perfected the wind engine achieving a 59% efficiency in his retirement was extremely inventive. He held some 80+ patents on suspension designs and he developed the Packard Torsion Ride which Jay Leno extolled with his Packard Caribbean.

When I told him that I loved the design of the Mog he quickly winced and said no-no! 3 wheeled vehicles are exceedingly dangerous. This proved to be true in the Progressive insurance Automotive X-prize. Watching one of the vehicles spin a 180 on the breaking test was scary as hell to one who understood what Bill Was saying.

He also in his retirement perfected suspension designs saying that it was a shame that he had not discovered the truth earlier. And he did this with a very simple test that an intelligent child could perform.

He simply used a board and made an inclined plane. He then built 3 exquisite models that really belong in the Henry Ford Museum. One was a 4 wheeled configuration, one 6, and one 8. Simply placing them on the inclined plane and letting them roll revealed that the 8 wheeled vehicle rolled much farther than the others. And yes, the 6 wheeled vehicle rolled farther than the 4 wheeled vehicle. Bill would look at you and smile and say the 8 wheeled vehicle has a much lower rolling resistance by a factor of 4.

Think about the common rail car. It has 8 wheels in bogied pairs. Believe it or not, it has that configuration for one reason only... much lower rolling resistance.

Bill's design was clever, Yes there were 4 bogied pairs and there were two walking beams connected at the center as a hinge. The springs were traverse at each end.

When The team from Keio University brought their 19 passenger car to the NAIAS they indicated that it was tested at 200mph and it had 8 wheels, the suspension was hydraulic but configured the same way Bill did his. The ELIICA is a more normal automobile with 8 wheels and it's outstanding performance is attributed in part by the low rolling resistance configuration.

It is time that we disabuse ourselves of thinking that less wheels provides a lower rolling resistance as Bill Pointed out. Sir Alex Moulton mentioned to me that as a youngster he was delighted to play with a Packard and ride it up and down with his friends as it self leveled.

Insightfully Innovative engineers are a thrill to behold.

And I'd bet that the Danish Engineers could come up with a design like Bill's that would delightfully surprise even them.

Bill Dickens

Island Architect

Will someone please re-set the Way-Back machine to Oregon in the 1990s; then a later trip to California in 2007? Thank you.

Chris Jordan

At least it's free. Spaceframe? LOL Well, you do get what you pay for!

Larry Hooten

Hi Clark Brooks and Bob Stuart,

You are wrong. Its as simple as that. This is an example of excellent engineering. A strong and flexible lightweight frame, with no triangulation in the way of chains etc that any person can build using only handheld tools. You are a slave of habitual conceptions. Bucky was not.


Pedal trikes of this sort are legal and common in the USA.

William Volk

The big problem with gasoline powered bicycles is that americans are sort of outlaws. The 49CC models are legal. But if you look on Ebay or most anywhere else people want the motors that look like 49CC units but are larger. That leaves the users at the mercy of the cops. Some cops can glance at a motor and know quite well whether it is over 49CCs. Many are 60 CCs or even larger. One way a cop can tell is when he notices a bicycle floating along at 45mph. The 49CC motors can't give that much output. The joy of those motors is that they are so cheap. Depending on the poison you want anywhere from $50. to over $100 gets you a brand new motor. If the carb gets glitchy then $20 will easily get you a brand new carb. On top of that some electric bicycles are now illegal in the US. One gets a range of fifty miles and can go better than fifty mph. The only thing holding them back in Europe is price. Most folks don't want to spend $8,000 on an electric bicycle.

Jim Sadler

Yeah, right. I'm seeing 10 kg of tubing, 2 kg of hardware, 3 kg of wheels, 5 kg of drivetrain, and bolts that need to be tightened every couple hundred km.

Clark Brooks

3 wheeled vehicles are not dangerous or unstable unless the single wheel is in the front.

Jerry Peavy

This trike is very interesting as a design project as creative room seems quite unlimited. I do however have strong doubts about safety and stability att higher speeds (>30 km/h).

Being the owner of a HP Velotechnik trike I also am convinced that these vehicles will consume a lot of rubber. It is not uncommon that you have to get new tires every 2000 to 5000 km on a balanced, light trike where the wheels are perfectly aligned. I doubt that the tires on the XYZ Spacefram will last more than 1000 km.

Magnus Billberger

Aluminium's ability to resist corrosion won't be worth a damn when you bolt it together with stainless bolts. I'd give it a year before the dissimilar metals start to affect structural integrity. I like the concept though, except it's butt-ugly!


re; Jerry Peavy

Three wheelers are stable so long as the weight is inside the tripod and low. It does not matter whether the single tire is in front or the rear.

re; Bob Stuart

Then why do aircraft manufacturers pay the weight penalty for using Alclad?

re; Clark Brooks

Locking nuts. Look into them.

re; Magnus Billberger

Granted miss alignment eats tires but with the exception of low quality control in the building I see no reason to believe that this trike will be inherently miss aligned.


While one might wonder about the rigidity of the front wheel supports, there is triangulation at the ends of the main frame. Note the solid plate at the crank and the rear sprocket, with more than one bolt top and bottom. Much like a large warehouse, where not every bay is braced between columns.

As far as dissimilar metals, here is something that may be useful:

"The general principals discussed here are that aluminum and stainless steel are not actually galvanically compatible because they have significantly different potentials, but the passivity of both can reduce the problem to non-problematical for non-critical applications if the area of the aluminum is greater than the area of the stainless steel (stainless fasteners on aluminum architectural features usually aren't a significant problem, but aluminum pop rivets on stainless steel sheets would be)."

So, keep it dry and you should be OK. And if you have a friend with a TIG that might give you more piece of mind.

Bruce H. Anderson

Someone might want to tell Bill Dickens about all the successful recumbent trikes with similar layouts that have been around for years. Two wheels in front and an unmatchable low rider placement both contribute to incredible stability and cornering ability, as well as less frontal profile so less total drag.

If physical problems make regular bikes painful, and if you don't see too many hills, a trike would be awesome. Otherwise, a conventional bike.

That said, this trike seem seems more than a bit suspect. Trikes have bigger frames and an extra wheel so they are inevitably heavier than a similarly built conventional bike would be. With all these tubes and bolts, this has got to be quite a bit heavier than a nicely built (ie welded) frame. People have already lamented the obvious lack of any triangulation. Lots of structures are bolted together. Vehicle frames, um, not so much. Why is that, I wonder. Those bolted joints are stressed, and even if you tighten them and use locknuts, I can guess those stresses will tend to deform and partially collapse the square tube. Potentially a flexy rattler, IMO.

It would probably work, though, be stable, and no doubt is reasonably easy to put together. This would probably be cool if cheap mass produced bicycles didn't exist all over the planet. But they do. Also, guys who can weld can be found in just about any town and farm.

As for aluminum tube - I use aluminum a lot because it's so easy to cut on a bandsaw and drill. But thin walled CrMo or even plain carbon steel works too. Lots of stuff where strength to weight matters, from aircraft, bikes and motorcycles use CrMo steel still. Easy to weld, less fatigue problems - and a bit of spray paint is no trouble at all. Uncoated aluminum alloy out in the weather gets white flaky oxidation and develops pits.


I am really impressed by all the clever heads out there. It makes me feel like stating a few facts:

I have used the XYZ TWOSEATER every day in one and a half year in the rough danish climate. I have exposed it to all kinds of testing to see if anything would break. ( Torture on a daily basis). Half of the time it carries two persons or goods from the grocery store. Its possible to make more lightweight trikes. However this is still very lightweight. Designing is a compromise between a lot of different factors. I don't like carbon fiber because of environmental issues. Welding sucks and paint is not an option here. Triangulation would prevent using the space inside the frame the way we do. I have not fastened any bolts after the fabrication of the cycle. We use locking nuts. Nothing broke down. There has not been any sign of galvanic corrosion worth mentioning. If you look under the washers in the most exposed places, you can still see the markings from my pen used to mark the drill holes. I must admit that if you keep the cycle submerged in seawater it wouldn't last for a long time. But most people dont live submerged like that. Furthermore all modern aluminum bicycle frames have got meetings between steel and aluminum. And it seems to work just fine. General corrosion: The alloy is quite soft, meaning that it contains a large percent pure aluminum, meaning that its oxidizes really fast and creates a good sealing.

How about just enjoying this totally new way of building durable lightweight cycles and celebrate that its still possible to rethink something as common as a cycle? How about enjoying the fact that we here have a way of building that would allow anybody to design and construct their own vehicle at a reasonable price?

Thanks for some of the more knowledgeable comments by the way. There are some interesting ones among all the utterly stupid I-know-better stuff.


I'd like to add a remark and two questions. The remark: It has been mentioned that a two wheel vehicle is lighter and more "fuel efficient" than a three wheel vehilcle. On the other hand a threewheeler offers more comfort and has advantages during standstill and very slow riding. If you want to stop, simply stop.

And now for the questions: 2. I am very tall, so usually it is hard for me to use a mass production bike. Does the N55 construction plan offer a possibility just to make some tubes 15 to 20 percent longer and give me the extra space I need to fold my legs into? 2. Is there a list of tools required to build such a vehicle? 3. Is there an accurate calculation about the cost of the plan and the materials to build such a vehicle?

Frank Kemper

N55 - You don't have to be rude as well. I'm well aware of both the uses of flex and rigidity. On my Car-Cycle X-4, they are confined to the appropriate places, giving far more suspension motion without incurring handling problems, and a much more rigid pedal support. I repeat: this is not what any engineer would call a space frame. It is a paralell beam construction, in both appropriate and inappropriate places. There are many compromises and problems with bolted construction, too, especially with dissimilar metals. Any friction will damage the oxide layer on both SS and Aluminum, allowing corrosion as well as galvanic action.

Bob Stuart

re; Frank Kemper

I an not an engineer but from practical experience I would have no qualms about extending the frame to give another foot of leg room. Gluing a 2mm thick sheet of aluminum along the side and top of the lengthened section of frame would greatly strengthen it as well.


I am really quite confused with a lot of the comments on N55's free plans and ideas it seems a lot of people seem to have the idea they have purchased them and are not satisfied with the product.

whereas in fact if you don't like the design the materials or the engineering involved,why not come up with some useful comments on how people can improve on the design within the original brief of cheap and easy with basic tools?

I have access to a TIG and make my own 2 wheel frames from steel, aluminium and titanium but still intend to make this vehicle as in the plans. I will probably change things as I go along but have no intention of putting the project down before doing so,and after experiencing it first-hand , I will post any mods that were required at that point as requested by the designers.

after all isn't the whole idea of this system to promote cheap easy cycling to all ?

Darren Mcmahon
Post a Comment

Login with your Gizmag account:

Related Articles
Looking for something? Search our articles