Building a Recumbent Bamboo Trike Frame

I've always been fascinated by bamboo and when I decided to build a recumbent trike it seemed like the obvious material choice for me.  Bamboo is beautiful, light, stronger than mild steel and renewable.  It does present some challenges however, as culms or poles are not perfectly round, taper from end to end and remain flexible even when cured.  So building a 3 dimensional trike frame required a lot of planning, trial & error, and some techniques to account for the variable size of the bamboo.  This instructable will focus on the design and construction of the recumbent trike frame.  

Before building this trike, I had never built anything that moved or worked on bikes.  I had also never constructed anything using bamboo, carbon fiber or epoxy.  Needless to say, I needed a lot of help and resources to get this project done.  My primary source of information on trike building was www.atomiczombie.com.  Brad and Kat at Atomic Zombie sell plans for building recumbent trikes from old bikes.  Brad has put together an entire library of picture and video tutorials on bike building and maintenance.  The AZ online forum is filled with DIY builders ready to give advice on every aspect of recumbent trike building.  Without these folks, I'd still be doodling.  I purchased a set of plans from AZ (Warrior trike) to learn how to build the steering, front axles, hubs, and disc brakes.  Since these specific details belong to Atomic Zombie, I’m not going to divulge their plans, but I highly recommend purchasing a set for building out the rest of the trike.  They are very easy to follow, well illustrated, and reasonably priced. 

Other good bike websites I use:
http://www.sheldonbrown.com/
http://www.recumbents.com/home/
http://www.ihpva.org/Projects/PracticalInnovations/weld.html#Chapter_3%20design
http://www.bentrideronline.com/index.php

Bamboo resources I found invaluable:
http://www.instructables.com/id/Carbon-Fiber-Bike/
http://www.instructables.com/id/How-to-Build-a-Bamboo-Bicycle/
http://www.instructables.com/id/How-I-built-a-carbon-bike-frame-at-home-and-a-bam/
http://www.instructables.com/id/Bamboo-Bike-2/
http://www.instructables.com/id/Bamboo-and-Hemp-Road-Bike/
http://bamboobike.wordpress.com/
https://plus.google.com/photos/117002944570352643588/albums/5374198633113536545?banner=pwa
http://build-its.blogspot.com/2010/09/building-bamboo-bike-frame.html

Step 1: Safety First

Don't forget to be safe.  It's easier to put on a gloves than skin.  Wear gloves, safety glasses, earplugs and masks where appropriate.  

I also want to warn you that I'm not an engineer, a bike professional or certified in any way to do what I've done here.  I'm completely self-taught by reading as much as I can and I certainly don't know it all or have much experience.  My goal is to build a safe trike which will provide safe enjoyment for years to come.  Read and educate yourself as much as you can and I look forward to getting your comments on how to improve my techniques.  Let's stay safe out there!

Comments

[derfpa]

Very neat solution, I like it a lot!

[softenersreviews]

Amazing! So easy anyone can do it! Thanks for the well put together 'ible! You rock!

[abadfart]

very nice what did you do for the hub, i have considered lathing a hub and using push in skate board bearings

[kentdvm]

Thanks!
I bought my hubs from Bitex. http://www.bitexhubs.com/htm/index.php
Here's a link from AtomicZombie you might consider on building hubs.
http://www.atomiczombie.com/Tutorial%20-%20No%20Lathe%20Trike%20Hubs%20-%20Page%201.aspx

[abadfart]

im not seeing the price on the bitex hubs what did it cost you

[kentdvm]

I'm trying to remember but it seems is was less expensive than you'd think. Something like $60 for 2 with shipping. Sorry I don't have a better memory!

[abadfart]

no problem that is about the ansure i was hopping for

[ch4r3l]

Very well documented, well done and nice instructable. I really like your trike.

I planned on doing a bike tour through Europe, mostly to northern Europe, maybe Scandinavia. Seeing other trikes and recumbent bikes, I thought about building one. I still can't decide on a bicycle or a trike because of following reason:
If you go fast (up to 50 km/h or 30 M/h) and make a turn, do you risk to fall over?
This would be the only drawback for a trike imo, though it's advantages would be that you can maneuver it more easily, ride stabler with slower speed (e.g. uphill) and it would be easier to ride in a city.


Thanks for your effort to post this and your precious information!

[ch4r3l]

I also wanted to ask, but forgot; how does the bamboo hold up in long-term endurance? Does it keep its quality in moist or rain (fog during night, rainy days...)? Can it last at increased usage over a long period? Would you use bamboo in my case where you'd depend on it for, let's say, 1 and a half month on a daily basis? Would you rather use a normal bike or a recumbent vehicle for pulling a trailer?

I also thought about the differences between recumbent bikes and trikes and came up with an idea of a recumbent bike with two helping wheels next to the back wheel that could be unmounted/mounted to switch between both vehicle types.

Any help or thoughts are very appreciated.

[kentdvm]

This is the only recumbent trike I've ridden and I've not ridden it much unfortunately. That said, your center of gravity is very low and it would be difficult to turn this trike over. The hardest part is keeping your butt in the seat as you need tend to slide. Not a big deal if you anticipate the curve and lean into it. A trike is great on hills since you don't have to balance. For me, I love being able to lay back and enjoy the ride in comfort compared to a bike. And for most people, a recumbent trike if fast since you are so low to the ground and you are pushing against the seat. More bang for your buck.

If I were heading out on the trip you are describing, I'd take a different trike. The main reason being that if you break down, no one is going to be able to help you fix it. Whereas a bike shop could help you with a metal frame. I think a bamboo trike could do the trip, but things happen and you could find yourself stuck somewhere. Bamboo bikes certainly stand up to long rides, mountain biking, etc and the bamboo is sealed so weather isn't an issue.

Check out www.atomiczombie,com for great plans on building recumbent bikes and trikes. You'll get a lot of ideas and info from them.

[kentdvm]

Forgot to mention weight. It ended up a lot heavier than I thought once i got the fat tires, seat and all my junk on it. Weighs around 55lbs so i certainly didn't save any weight by building it out of bamboo. Check out www.atomiczombie.com for a lot of info on building and also plans.

[ch4r3l]

Weight won't be an issue since a few kg less or more won't matter with a trailer. When we (2 of my brothers and my father) made our bike tour from Luxembourg to Italy we crossed the alps and I had to carry twice as much weight as the others and it didn't matter much to me.

As for the low cg, I want to build a low racer similar to this one (with the same back-wheel construction as yours):

http://forum.atomiczombie.com/gallery/showimage.php?i=87&c=12

Thanks for the fast answer!

[Misterbee]

What a great looking trike! I have ridden trikes for years, and have tout about building my own. Now that you have had it a while, can you comment more on how it rides? And do you mind me asking what the finished weight is? Great job!

[kentdvm]

Thank you! Unfortunately due to "life", I haven't ridden it much so I can't add a lot. This is the only recumbent trike I've ever ridden, but I'm sure it has more flex than a metal trike. While that makes it comfortable, the flexibility makes it feel less responsive. More swishy in how it handles. The only riding I've done is with my young son so we haven't gone on any long rides. I've been very pleased but I can't really comment on how it will hold up over time. The question is really more about my craftsmanship than the bamboo. The bamboo is very strong and I don't see it failing anytime soon.

[veryrealperson]

Was the pvc version rideable?

[kentdvm]

No. It was pretty flimsy and only dry fit together. Simply a model for cutting and orienting the bamboo pieces.

[gjm]

Beautiful job; I like the way you used PVC pipe for the full scale model, very smart.

[cassiel007]

Beautiful bike, I love the idea of using bamboo. I like idea of the PVC pipe model. Just a pity can't cant be used to build an actual bike.

[mspark]

this is a real beaut! Do you have video of the trike yet? Id love to see some closeups in the vid, and pics too?

Im thinking that a person could use the seat tubes you made as the seat itself. Many bent makers use sling seats, the build would be lighter, and quicker as the seat you made wouldnt be necesary. Though some of those dowel triangulations you made would have to be moved somewhat to allow for the shape of a persons backside to rest inside....

[kentdvm]

Thank you! I need to shoot some videos but just haven't yet. I originally considered using a sling seat but went with this type mainly for the stability of the frame. The triangulations you mentioned, ect. The bamboo has so much flex but it might be possible to make it work another way.

[frankcox]

There is a method of joining bamboo I was taught by an old fisherman as a kid that will even make a but joint in pot metal indestructible. And it is simple, fast , and cheap!
Use nylon thread and epoxy , that's it! Rap the thread tightly and then soak with epoxy . Once it gets tacky weave the thread diagonally over the first layer then soak it add another layer rapped like the first , that;s it. On the thicker pieces it might be faster to use masons line which is incredibly strong stuff , it comes in differing strengths.
Try it , I guarantee the bamboo will fail elsewhere.
Cool project , how long did it take?

[kentdvm]

Good idea. Much cheaper than carbon fiber that's for sure.
It took me about 6 months working on it when I could find time. There was a lot of head scratching also. Thanks

[frankcox]

Forgot to mention you can use different colored thread on the outer rap to decorate the joints.

[snotty]

Amazing, beautiful work!

The first time I built a recumbent it was high and short and bucked me forward when I rode over bumps. This was unpleasant.

How does yours handle when riding over things like small speed bumps?

It looks like you have separate breaks and non-Ackermann steering. Does it pull to the side at all if you break on one side only? And do you have any trouble cornering with your steering arrangement?

[kentdvm]

Thank you! It takes bumps very well especially with the bigger tires. The angle of the seat makes it feels a bit like riding a recliner. With that degree of recline the only thing that has thrown me forward is locking the front brakes at high speed. Doing that will actually lift the back wheel off the ground.

It has Ackermann steering although not your typical set-up. I kinda made that part up by welding a couple pieces at 45 degrees on the steering arms to get the tie rod pins on a line running from the front axles to the center of the rear wheel. It turns well although I might change my handlebars at some point. When you turn hard you have to slide your butt to the side a bit. A lot of trikes have vertical handle bars but I liked the feel of having my hands at elbow level for comfort. Considered under the seat steering but that seemed to just complicate things -- primarily attaching the handlebar headset to the bamboo, etc.

I can't tell that it pulls much when braking. Whatever pull is present is easily compensated for and I haven't noticed much of a problem.

[Silence]

I want one of these ! A good recumbent costs so damn much though.
Ill build it from aluminum or steel though, I tend to break fancy things.

[Uptonb]

Congrats on being a finalist, and good luck!

[kentdvm]

Great! Can't wait to hear!

[Renatofuzz]

Great Project!

[marcintosh]

This is GREAT!  I've wanted to have a bike like this for quite a while.  
One of the things that struck me is the intricacies of the cutting and fitting and connecting.  Since bamboo is a wood type product might it not have been possible to build a mandrel and bend the bamboo instead?
The tight angles might not be possible and would add a bit to the over-all-length but it might simplify things a bit.

http://www.youtube.com/watch?v=iV-CE3hW4ss

and a longer version

http://www.youtube.com/watch?v=YYEPUpG3f4M

Just a thought- thanks again
M.

[kentdvm]

Bending bamboo was my original plan but it flopped. I had watched those 2 videos and those guys make it look pretty easy. When I couldn't do it with a torch, I build a 8' long steamer. When I couldn't do it with torch on steamed bamboo, I gave it up. Ended up with burnt bowed or busted bamboo and that was about it.

I wasn't trying to bend it into a tight radius just a gentle bend like a 30" radius. The stuff is tough and stubborn. I built a form too so I could clamp one end and add clamps as I went. That made it hard to heat but I still managed to burn the fire out of it.

IMO there are certain bamboo species which bend easily because they aren't as strong. In the end, I reached the conclusion that the bendable species probably weren't strong even to be safe for trike building. I still have in my mind to grow bamboo and force it into forms as it sprouts. Once it's fully grown, wait 3-5 years for it to mature and harvest your bend trike pieces. Unfortunately, this involves gardening;)

[marcintosh]

Ended up with burnt bowed or busted bamboo and that was about it.
Ah, I see.  Too bad.  I've had great "fun" bending Maple for sculptural forms and was looking to make life easier.  I've used a heat gun simply because I could build a fixture to hold/steady it while I moved the wood piece.

I still have in my mind to grow bamboo and force it into forms as it sprouts. Once it's fully grown, wait 3-5 years for it to mature and harvest your bend trike pieces.

Minds eye shows this odd forest of "Trike Frames" stretching out for acres.

Unfortunately, this involves gardening

From what I've seen not much in the way of gardening though.
 
I wonder if there's any way to laminate the bamboo with out it becoming a project on it's own . . .
Oh well I tried and obviously you tried harder - thanks for the smarts.
M.

[milesfromneihu]

Rattan is usually the material of choice when bends are required. My feeling is that it is not as strong per unit weight; also, it is solid, not hollow like bamboo. I've never worked with it myself, but I have spent a lot of time sitting in rattan chairs, sofas, and rockers. You can see that it takes bends really well. Rattan furniture is very popular here in Taiwan.

[smy1]

hey i was curious, do you know roughly how much it costed in matrials?
I have to say it looks very slick.

[kentdvm]

That is a good question. The frame is the cheapest part of the trike compared with the wheels, rims, hubs, etc. Off the top of my head, I believe I spent $70 on bamboo, $40 on carbon fiber and $50 on epoxy resin (all via ebay). Plus shipping. Then there's the dropouts, headsets, disc brakes, 9 speed hub, rims, tires, etc, etc which are the bigger costs depending on what you use. And the equipment and tools depending on what you already have in your shop. So I'm guessing I probably spent around $1500.

[olmon]

Considering that your would have paid $4K + for a similar commercially built trike, I'd say you did great. I built my own LWB EZ Racer clone for about $75 parts & materials, but I don't have disc brakes or some of the other niceties you have on your trike. I have in mind to build a FWD delta trike in the near future, but it won't be as nice as your tadpole.

[smy1]

thats not to bad. thanks.
and again awesome job

[kentdvm]

Thank you!

[paqrat]

Please forgive my ignorance but wouldn't it be easier just to make the bike out of pvc reinforced with the carbon fiber?

[olmon]

That would have rather defeated his goal of using bamboo - - & besides, I have seen pedal vehicles constructed from PVC, they tend to be rather ugly aside from the fact that over time ultra-violet from being in the sun tends to make PVC brittle.