Materials: This is a 2nd dress pass welding sequence of a custom titanium bicycle frame. The area being welded is the headtube/downtube/toptube junction. Tubes are Grade 9 aerospace titanium and filler wire is Grade 5, flag-tagged wire. The frame is a custom 29er mtb.
If you have ever wanted to build your own bicycle frame, but can't afford a framebuilding class or the materials to braze a frame, building one out of bamboo and carbon fiber is a great and relatively inexpensive way to get started. In this Instructable, I will explain in detail how to build a great looking bamboo frame. After that, you will learn how to make some LED spoke lights to go along with your DIY bike, or any other bike you want to put them on.
WARNING: If you are not comfortable with being stopped by strangers and answering their questions about your bicycle, this is not the project for you. And DEFINITELY do not build the spoke lights.
Bamboo: I used 1 7/8" diameter for the down tube, 1 3/8" for the top and seat tubes, 15/16" for the seat stays, and 1 1/16 for the chain stays. All values are approximate, and anything close to those should work.
Carbon Fiber Tow: I got 5000 meters of it off ebay for 50$. I have enough left over to build at least 4 more bikes.
Epoxy: I used West Systems 105 resin and 205 Hardener.
Old Bicycle Frame: I chose to cut apart an old frame for the lugs, rather than buy new ones. Using an old frame also lets you get away with not building a proper jig.
Propane Torch: For heat-treating the bamboo.
Basic hand tools: Saws, a decent knife, a drill, a rotary tool.
Electrical Tape: For compressing the carbon fiber while the resin hardens.
Aluminum angle bar: For making a simple stand to hold the frame in place.
Threaded rod and nuts: For holding the dropouts in place in the stand.
Spar Varnish: For finishing the bamboo.
Paint remover: For stripping the old frame.
Sand Paper: For sanding, of course!
Rubber Gloves: For working with epoxy. Apparently, you can develop a nasty allergy from too much skin exposure to the hardener. You will need at least 50 pairs of these.
I used west 105a resin and 205a hardener, which is the smallest size set West sells. I used about 3/4 of the epoxy. I bought dispenser for the containers, which dispense them in the appropriate ratio, which is 5:1.
I don't know exactly how much I used, but it was definitely under 1000 meters. I managed to find a 5000 meter roll for $50, which was much cheaper per meter than buying less. I would just pick the least expensive roll of 12K tow you can find of at least 1000 m.
I've not found anything anywhere near that cheap. So guess I'm gonna have to keep searching. If you come across anything ever, if you could let me know I'd besuper grateful and name my bike the Technochicken.
Couple of quick questions as I am seriously considering building this bad boy based off of your work.
I noticed that you completely removed the whole top section in the second pic and then completely replaced the lug beneath the seat with a bamboo setup.
Since i'm concerned with my ability to make this without a jig, would it be possible to just keep the seat lug (have no idea what its called) and then just put bamboo in place of each tube in succession?
Since you opted to remove the seat lug (for lack of a true term) is there a reason for that? Just want to weight the pro's and cons of doing that.
It would be completely possible do build the frame without removing the seat cluster (I think that's the technical term), and it has been done this way:
http://www.instructables.com/id/Bamboo-Bike-2/
I chose to not do this for a couple reasons. Firstly, my donor frame was steel, so leaving that part of the frame in would make the frame significantly heavier. Secondly, the donor frame I used used a non-standard seatpost diameter, and I would have not been able to find any decent seatposts for it.
Great instructable! I would like to know how you decided what sizes of bamboo poles to use. Also did you do anything to prevent corrosion at the steel carbon interface? If not has corrosion been a problem for you?
The rule of thumb for bamboo diameter is to use at least what a standard aluminum bike of the same size has. Any less than that, and the bike will have too much flex. I chose to use even wider bamboo than most aluminum frames had. This makes the bike a little stiffer, at the cost of weight. I also like how it looks with the wide bamboo.
As for corrosion, I have not had any problems. I did not insulate the steel in any way, although some builders do wrap any metal in a layer of fiberglass before wrapping carbon around it. I have seen a lot of discussion about whether or not carbon on metal will cause corrosion, but the general consensus seems to be that it is not an issue for the conditions bicycles are exposed to.
I am desperate to do this. I live in the UK and cannot find bamboo poles for love nor money though. If anyone could point me in the right direction I'd be forever indebted....
i'm sure you'll find some. Either go to the garden shop and buy a plant and wait for a few months, or maybe you'll find some at a fancy asian hotel and maybe they'll let you take a pole or two
Great work. I really like the tone you heat treated the bamboo to. The badge on the head-tube is also killer. With the over sized chain stays, did you run into any spacing issues with the cassette or sprocket? Please let us know if your seat-tube cracks or breaks. One of the other bamboo bike instructables had that problem as well. Make sure your seat post is plenty long to distribute that pressure.
I think you should add a step describing how you added your cable stops!
The over sized chain stays will only cause problems if you want to run double chainrings up front, or if you are using a narrow BB. I have a 52 tooth chain ring up front, and it has about 1/2 a cm of space between its edge and the chainstay. As is shown in step 8, I did have to remove some material from the seat and chain stays on the right side of the bike, where they got in the way of the sprockets.
I'll definitely add more info about the cable stops. Thanks for the suggestion!
Judging by this, I doubt it:
http://forums.roadbikereview.com/showthread.php?p=2671685
Some full carbon fiber frames weight limits are under 340lbs, and they are certainly at least as strong as a bamboo bike. If you really overbuilt it, using extremely wide diameter bamboo and a whole lot of carbon fiber, it may work, but all bets are off.
You'd be surprised. http://www.youtube.com/watch?v=C5VdRaJkc7c There used to be another video where they used the same bike to haul two bags of cement. They had to reinforce the spokes (like you see in the video), but the rest of the bike was fine with the weight (like 500+ pounds with the rider).
As others have said, this is probably the best DIY bamboo bike around! Good job! I have a spare doner bike im going to use. Unfortunately here in Ontario, its next to impossible to find 'green' bamboo to do what you've done. Luckily i found some varying diameter pieces at the local Home Depot to use...no cracks! Hopefully when i sand them down, there is a nice golden shade revealed like yours. I clicked the vote button. :)
It is over a pound lighter than the cheap steel frame I cut apart, so probably about the same as a high quality steel frame. It is definitely heavier than an aluminum or CF bike. However, if I had used aluminum lugs and built the frame a little smaller, it would be significantly lighter.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310318614226&hlp=false&rvr_id=233134391388&clk_rvr_id=233134391388&crlp=1_263602_304652&UA=%3F*S%3F&GUID=a8cafdb01250a040d7c0f0d0ff75ec74&itemid=310318614226&ff4=263602_304652#ht_4185wt_1139
I noticed that you completely removed the whole top section in the second pic and then completely replaced the lug beneath the seat with a bamboo setup.
Since i'm concerned with my ability to make this without a jig, would it be possible to just keep the seat lug (have no idea what its called) and then just put bamboo in place of each tube in succession?
Since you opted to remove the seat lug (for lack of a true term) is there a reason for that? Just want to weight the pro's and cons of doing that.
http://www.instructables.com/id/Bamboo-Bike-2/
I chose to not do this for a couple reasons. Firstly, my donor frame was steel, so leaving that part of the frame in would make the frame significantly heavier. Secondly, the donor frame I used used a non-standard seatpost diameter, and I would have not been able to find any decent seatposts for it.
As for corrosion, I have not had any problems. I did not insulate the steel in any way, although some builders do wrap any metal in a layer of fiberglass before wrapping carbon around it. I have seen a lot of discussion about whether or not carbon on metal will cause corrosion, but the general consensus seems to be that it is not an issue for the conditions bicycles are exposed to.
like the add of the POV's - any you made them your self too - sweet!
( i have a solar powered led system wrapped on mine - about 60 lights)
Great Job
Happy cycling to you and yours
- chase -
Dónde consigo Bambú en Chile por la csm....
I think you should add a step describing how you added your cable stops!
I'll definitely add more info about the cable stops. Thanks for the suggestion!
http://forums.roadbikereview.com/showthread.php?p=2671685
Some full carbon fiber frames weight limits are under 340lbs, and they are certainly at least as strong as a bamboo bike. If you really overbuilt it, using extremely wide diameter bamboo and a whole lot of carbon fiber, it may work, but all bets are off.
I really want one.
thanks