Bent Plywood Bicycle

After seeing this bike on a bicycle design blog I was inspired to build my own. It was made by someone named John Hobson. The concept is the same, but mine is fairly different.

Also I had some left over epoxy and fiberglass from a kayak I built and was just itching to find a project I could use it on (or maybe I was just itchy from all the fiberglass). Anyway, since I wasn't thrilled with my current bike that was a cheapo 15 year old big box store bike, I thought it would be great to replace the old frame with a wood composite frame and have something unique.

The part of the design I liked was that the top and bottom parts of the frame are like leaf springs separated by the seat tube. I thought that having a suspension system integrated into the frame was a really cool idea. Ideally vibrations and bumps would be absorbed into the frame and returned back to the wheels, without making the frame too bouncy. The frame I built consists of plywood, fiberglass, epoxy, and even paper, so there is no welding required.

Before I get started here's some bike terminology I had to learn:
Head Tube - short tube for the handle bars, and front fork assembly.
Top Tube - horizontal section that connects the seat tube to the head tube.
Down Tube - diagonal section that connect the head tube to the bottom bracket.
Bottom Bracket - This is where the pedals and crank attach.
Seat Tube - longer tube that the seat post slides into.
Chain Stays - Two sections that connect the bottom bracket to the rear wheel.
Seat Stays - Two sections that lead from the seat to the rear wheel.
Dropouts - brackets to connect the rear wheel.

Caution: Riding a bike is dangerous, riding a home built bike is even more so. If you decide to build a bike, take it slow, wear a helmet and other protective equipment, reinspect your work, and be prepared for it to break at any moment.

Step 1: Get The Materials

I looked at the 1/8 inch plywood at Lowes and Home Depot, but I wasn't very happy with the quality. I then went to a local woodworking store and found some good looking 1/8" baltic birch plywood in 5'x5' sheets that had a nice light color. It was about $20 per sheet so if it turns into a disaster I wont be too upset. I also bought a pack of birch veneer to wrap around the seat and head tube.

I bought a bottom bracket, bottom bracket shell, and crank from Amazon for about $50. The rest of the parts I plan to take from a junk bike I had lying around.

The fiberglass, epoxy, and spar varnish were left over from a kayak build. I bought these online from a boat building supplier. It is 6 oz glass cloth and the epoxy is clear, non-blushing that takes about 24 hours or more to fully cure.

Tools needed: Saw, sandpaper, rasp, a couple of pliers, drill, power sander, power jig saw, some solid wire, natural fiber rope or twine, a vise, and several disposable brushes, cups, and latex gloves. When needed be sure to wear eye protection and a mask to keep gunk out of your lungs. I also had to buy some specialty bike tools, a chain tool and crank arm remover.

For removing parts off the old bike I used a hack saw, locking pliers, bench grinder, and a Dremel.

Comments

[scraptopower]

This is awesome! 5* and my vote!

Is this springy to ride ?

[LongToe]

Thanks. No, it's not very springy, but I'm kinda a light weight. It might be a different story though for a big dude.

[dbell]

I'm not a bike builder, so may be talking out my butt here, but from a structural point of view, you have assembled a very rigid frame, and it wouldn't have much spring to it.

How would it work if the seat tube passed through a sleeve set into the top tube/seat stay arc, rigidly attached only at the bottom bracket?

Dave

[LongToe]

That sounds pretty cool. It would really act like a spring then. Someday I'd like to make a bouncy bike and really exaggerate the vertical spring. This bike is a little more practical.

[rowerwet]

great i'ble! I really want to make my own now!
from a stress stand point would it be better to have the pedals mounted inside the frame rather than outside? that way the force you put onto the pedals (downward) would be pushing against the frame rather than pulling.
I also have built ply and epoxy boats taking the construction to bikes makes sense.
If you used west system epoxy let http://www.epoxyworks.com/ know and they could make an article out of it, in fact they have an article about epoxy and wood bikes in it this issue.

[randomray]

Excellent build and very helpful instructable ! A few suggestions and thoughts . A simple jig to clamp the wood to will make this project much easier . You really don't need the fiberglass between the layers of plywood ." it'll be lighter and it's plenty strong without the glass " An outside rated wood glue would be plenty strong , then coat the outside with epoxy and glass " it'll be a lighter bike ". Leave the seat tube on the bottom bracket , run the tube through the holes in your wood frame epoxy it in then leaving a short section at the top and bottom cut out the center section and connect those pieces by wrapping with several layers of veneer . Or just cover it with veneer . I would take the donor headset and just cover it with veneer after installing it . If you wanted you could take 1/4" strips of wood with the grain running the length of the bike instead of the plywood and it would be far stronger . Hickory , ash , sitka spruce and white oak would work great . Mix in other woods for cool patterns and colors . Once again great job , now I'm going go build my own thanks to you . Do a search for wood bikes on Flickr there are some cool ones out there .

[LongToe]

Thanks! You're right, I'm not crazy about hanging the crank below the frame, but I thought putting it inside would make it too high. This design could probably be reworked for a better or cleaner looking crank mount either inside or laminated into the frame itself.

[LongToe]

Thanks, those are some good ideas. If you make your bike, you should make an instructable or post it online somewhere.

[mr-motorvator]

The loops make the whole bike strong and selective use of metalwork keeps the slender look. The bike design you mentioned is spoiled by the box for the seatpost.

Have you seen the Pashley Tuberider? It is a great looker. I fitted mine out with a motor system driving the chainwheel. Pashleys all have hub brakes, so motorising them is a challenge. Photos as www.mr-motorvator.co.uk

[HanzieO]

Hi, nice work with your bike. I am halfway with making a similar bike and I will post and instructable as soon as im done. This will be my second wood bike the first one is like a junk yard recumberant. See the foto below. I really like your bike and admire the workmanship. I will add a bit more steel to my bike coz I like the industrial look and I am a metal worker at heart. I used a jig for the laminating and both halves come out of the clamps tonight.

Does it still go?

[LongToe]

Cool man, I can't wait to see your instructable. Your recumbent looks great. Yep it still works but I broke off the seat clamp when I used a seat post that was too short. That's a place where steal would work better. Good luck with your build!

[HanzieO]

http://www.instructables.com/id/Wood-Bike-2/

[srichie]

I'm a bit confused about the frame. I see you've listed the materials that its made of, but i'm still not sure what the frame is... So the plywood is just a veneer, or outer layer? And structurally its mostly fiberglass? Has there been any stress tests done on the frame?

[LongToe]

The frame is 7 layers of 1/8" plywood with fiberglass sandwiched between each layer. I have no idea what loads it can support. Ride at your own risk.

[EvoQ]

I think you did a wonderful job on a first prototype. And just think you have inspired allot of people to do the same. that is what life is all about my friend.

Thnxx for sharing.

[LongToe]

Thanks!

[CryoFireProductions]

I have one question. How light is the bike? I'd think it'd be lighter then your average frame.

[LongToe]

The frame by itself weighs about 6.8 pounds and all together it is 32 lbs.

[altomic]

say, could you make the Bottom Bracket and Seat Tube in one piece.

That is the seat tube is welded to the bottom bracket - to make a "T".

you then have 2 holes in the bike frame for the seat tube to go through (from the bottom to the top) yeah?

the seat tube and bottom bracket are metal and covered in the veneer once inserted into the bike frame.

it would give the bottom bracket strength and you wouldn't have to have the stuff around it to hold it in place.

[LongToe]

Good idea. HanzieO did something similar to what you described on his version. http://www.instructables.com/id/Wood-Bike-2/

[thirst4know]

Nice design. A few improvements could produce a bike that will last a lifetime. Hardly any rust either! Great lines on your bike.

[LongToe]

Thanks!

[yoyology]

That is a beautiful object. The fact that it's a functioning bicycle as well makes it even more astounding. Well done, sir!

I see that you posted this a couple of years ago. Have you made another since then? I'd love to see an update.

[LongToe]

Thank you. I would like to build a beach cruiser version, but haven't gotten around to it yet. One of these days.

[savant77]

Awesome build man, great details, well placed photos and not perfect. So many people put up perfectly executed ibles that you know it was really thier 2nd or 3rd attempt. I personally don't mind the twine BB, whatever works, only time will tell if it holds up and since it's wood, just rebuild it stronger. I'm also impressed with the weight, I just built a cargo hauler based on a steel big store box bike that came out to 12 lbs! Do not put wood forks on if you like your front teeth!

[ac-dc]

... another project inspiring people to make a bike that can get them hurt or killed if they use it. Nifty idea, but, even professionally made bikes fail and with luck people should not get hurt just to have some novelty item.

If it were the other way around, if for some odd reason bikes were made out of plywood and someone suggested a STRONGER, BETTER frame from metal tubing I would applaud but this kind of suggestion that puts people at risk is very irresponsible. I propose some industry standards and laws that hold bicycle frames to standards for durability a bit like car crash tests and road-worthy regulations.

You only have one body and one life kids, please think before endangering it.

[voyageur10]

You have got to be kidding me... This is a great project, I'm sorry you don't see the value of it.

[janettetsmith]

Gee thanks, dad.  I'll be sure to never have any fun in my life as one of your charges.  Inventors and artists + that outlook = boring world.  I suppose we should really take everything made of wood and replace it with the sturdier, safer metal.  Goodbye wooden roller coasters.

[ac-dc]

Wooden roller coasters have to be tested for safety. Remember something, as smart as you think you are there is bound to be some kid out there that gets hurt senselessly.

To try to equate general inventions and artists? You really don't get it.

[janettetsmith]

Although no one official organization exists that is responsible for inspecting roller coasters, making that statement hit or miss at best, the same haphazard process applies to metal roller coasters, as well.

Furthermore, my level of intelligence has nothing to do with how well parents watch their children or the fact that through the fault of no one, incidents happen.  Safe to say everyone is thankful you were not Mr. Wright with sons named Orville and Wilbur.

[Rahdzhillaxxx]

I actually have had a wooden coaster break beneath my car once at Michigans Adventure a few years ago. a bystander saw the board beneath us shoot down into the ground and stick right into the hard earth. The kid attending said "I'll shut it down if it makes that sound again when the next car comes in" (That car had already left so I hustled out of there as quick as possible. that ride was shut down for weeks! nothing is a sure bet!

[janettetsmith]

I totally agree with you, nothing is a sure bet.

[Hiroak]

That's a very funny post. Because you can't be serious about this.

[ac-dc]

It's called responsibility. Putting an idea out there that results in an inferior machine that can hurt people, isn't...

[janettetsmith]

If you have empirical evidence this is an inferior machine that can hurt people, please, by all means, post it for those of us less enlightened.

[Transquesta]

Great. Just what we need. MORE government regulation to stifle initiative/creativity.

News flash, people: LIFE is risky no matter what you do. You can choose to live it or to spend your time on this earth in complete misery worrying constantly about the countless ways you might get hurt.

[ac-dc]

There's nothing wrong with creativity, when it results in an equal or safer product. Bicycles are also a means of transportation that can get people seriously hurt. Live a long and happy life by using common sense so you can achieve your lofty goals of creativity.

Life IS NOT very risky if you use common sense. No worrying required. If. You. Use. Common. Sense. Do you notice a trend here?

[paganwonder]

Sense is not common. However, accepting anothers opinion about what is safe or secure or correct is quite common. I work with deadly bodily fluids everyday without injury- it is not safe for the untrained and inexperienced but I am at minimal risk because I follow simple, but obscure principals which are not known to the general public. I am safe in these situations but you would be in mortal danger.

I would rather take my chances on this bike than drive to work- statistically I would be safer on the bike. I'll bet you don't realize that driving is the highest risk activity you have ever engaged in. Statistically you don't have a chance behind the wheel- but you 'run' out to the store without a second thought.

[paqrat]

I am afraid that common sense is no longer common, it is, in fact, a rarity.

[Transquesta]

I think the government banned it several years ago--along with any experimentation or creativity deemed 'unsafe.' :-D