How I built a carbon bike frame at home (and a bamboo frame too)

I have built this carbon composite MTB frame four years ago using simple building method which is described in this Instructable. Of course, this method is not suitable for mass production, but if you plan to build just one or two frames for yourself, it is sufficient and you can build your own frame of a high quality. The feeling of riding a self-made frame is great!

After years of riding, the frame is still okay and I am still alive too, although I prefer riding my bike equipped by the bamboo/carbon frame, which I have built using the same method described here. Until now, several frames have been built by this method in the world.

Step 1: Few important things you need for building the carbon frame

1. Frame jig - it is used to hold all parts in their exact position. I have built the frame jig from scrap wooden rods and some lathed parts and connected with screws. You can also build e.g. adjustable aluminum jig, where you can make the frame geometry according your needs. As a template of a frame dimensions for construction of a jig, I have used my bike frame that I rode before. The completed jig was stiff enough and guaranteed the position and the alignment of the metal parts during the construction of the foam core.

2. Metal parts - they include an aluminum bottom bracket shell, head tube, short seat tube, cable stops, rear dropouts and a rear brake bosses. The used thin walled tubes and cable stops were made on a lathe, for the carbon frame I have purchased rear dropouts and brake bosses from the bike parts supplier. I have made them by water-jet cutting for the bamboo frame. I prefer to use 7075 Alloy for the metal parts. It is good to have all aluminum parts anodized, as then you do not need to wrap a light layer of fiberglass around the aluminum tubes and part of the rear dropouts as an insulation between the aluminum and the carbon against galvanic corrosion.

3. Foam core - I have used polystyrene foam to make the core of the carbon frame. But it is better to use extruded polystyrene, or polyurethane foam, which is more rigid. Later I have used the polyurethane foam which is normally used for insulation of the outer walls of buildings.

4. Materials for laminating - I have chosen a bi-directional woven carbon cloth (180 grams per square meter). I have used MGS's L285 epoxy resin with hardener 285 for laminating. For the carbon frame I used about 3.8 sq.m of the fabric, for the bamboo frame about 2.0 sq.m. You can also use uni-directional carbon for the base layers and use the bi-directional carbon just for the outer layer.

5. Supplies - I used plastic kitchen foil for covering the workbench during the wetting out the carbon, latex gloves, a small digital scale for weighing of the exact volume of resin and hardener, cups for mixing, paint brushes for wetting out, lots of electrical tape, sand paper and a good respirator during sanding.

6. Patience - the more the better

Comments

[sanchits]

hello I would like to built one of these carbon or light weight bikes can you please guide me. Would like to take this as a part of my project, I recently graduated as mechanical engineer and worked on a car design project before but building a bike would be a new challenge for me. Please let me know how can I proceed.

Questions

1. Is there any standard global sizing for bike
2. Currently I am using Catia V5 what kind of factors and calculations do I need to consider?
3. what is the weight of your frame?

[srichie]

While the cost of carbon frames keeps getting very low, and is now pretty much affordable, bamboo frames are still a rarity, and priced accordingly. I'd love to see quality bamboo frames being affordable and widely available. Some day...

[ithica2012]

hi i think if u have seald the bamboo with a good quilty resin or varnish then it should last a very very long time my favorit fishing rod is a 85 yr old bamboo thats as flexable as if it were new beautiful job by the way

[jfaylor]

i am going to build a carbon road frame and i need to know where do you get your carbon along with what thickness, type, modulus, how much carbon thank you

[aamaral]

Hey, congrats for your instructable. A piece of art, really. Im into doing one for myself. About the weight, how much for the carbon and the bamboo frames?

[apaterson1]

how would i attach disk breaks to it? and is it easy enough to paint with ordinary paint? by the way amazing job!

[samsq1]

For the disk brakes, just buy drop outs with mounts build into them. I assume that you mean spray paint when you say ordinary paint, and as I have yet to do this instructable, I don't know how well that would work on it. In general, it can be hard to get a good paint job with spray paint it, as I found out on my steel frame. I wouldn't use spray paint personally. Hope I helped!

[apaterson1]

is the bamboo frame suitable for cross country mtb riding?

[SeaFire70]

I was thinking that it might be great for a fixed gear bike. My concern would be about the stress around the the bottom bracket and chain stays when skip breaking the bike, with both frames.

[sunildetecvision]

I like the valuable information you provide in your articles. I’ll bookmark your weblog and check again here frequently. I am quite sure I will learn many new stuff right here ! Best of luck.
Harley Fenders

[sunildetecvision]

The blog was absolutely fantastic! Lot of great information which can be helpful in some or the other way. Keep updating the blog,looking forward for more contents...Great job, keep it up..
Carbon Fiber Bicycles , Carbon Wheel Sets

[TopperHarley84]

Just got to say what a great artice this is a what a fantastic finished product, cheers for sharing.

Definitely on my list of things to do when I get some time/space/money etc etc...

[iluvcamaros]

Did you do anything special to the legs of the dropouts to create a better bond with the CF?

[fzdome]

did you leave the foam inside the tubes? if yes would you have any idea how to remove it? are you a student of BME?

[chrisandamanda]

Would you not want to leave the foam in to keep it firm?

[killersquirel11]

Looks like acetone might work
forum
just google polystyrene solvent (or whatever type of foam you used) then double-check to make sure that it won't eat your epoxy, too

[gymgutt]

so how do you cure it at 50 c? at the heater ? is it a stove ? or ? thanks !

[Ro]x[as]

Depending on the epoxy you pick, it's likely not necessary to actually cure at high temperature, although it will certainly speed the process up. I used a series of heat lamps for several hours on my frame, but perhaps even halogen lights could work.

[katyi.gyorgy]

where from have you bought the metal parts? could you help me out with this ? it's the  only thing keepeing me from making one
 

[snotty]

I cut my headtube, bottom bracket and rear dropouts off of a bike from the garbage. I used a short (maybe 10cm) section of tubing for the seat tube insert; maybe it would have been better to make this insert longer.

[m_68]

Hi! If you haven't find your solution yet, now I try to give some advice. Try at Deda, or Colombus tubi. If you're from Hungary as i suppose from your nick, you may try it at Sopron. Ask Yasec, he imports Dedaccai frame parts to hungary. Another try is worth at Újpest, when you shall ask Zsolt Matuz. He often gets bike frames from italy, smetimes frame parts too. If neither them could help, or you don't want to spend a lot on bike frame parts (yes, these are quite expensive), then write an e-mail, and I can help you on machining frame inserts out of aluminium to make shaped closures right. I have some experience with composite materials too. If wanna ask then write an e-mail

[history323]

Now I don't know if this will work but what I plan to do is purchase a cheap roadbike from goodwill or another resale store; and cut the metal pieces from that off and then use the flame pieces to mold my carbon fiber pieces- in theory the carbonfiber will fit perfectly into the metal!

[Ro]x[as]

This might work, but you have to remember that CFRP has different properties than steel or aluminum. The ideal tube diameter and thickness will be different for each material due to differences in tensile strength and stiffness.

[Ro]x[as]

 Have a look on the step 1 page, a few suppliers have been named.

[yoguy121]

hey man do you know if a frame like this or the bamboo version would be a good bike for doing jumps and gaps with because with it being light and all do you think it could stand up to being pounded on and dropped
please respond
thanks and great build i hope to build one someday
and how much was the total build cost
thanks again

[JT101]

What is the frame weight of this and the carbon fibre one? Beautiful!

[history323]

Hey, this is really nice! Just wondering if the CF bonds directly to the metal components, or do you have to take some sort of extra precaution to make sure the metal and carbon fiber stay together??

[Santorican]

I've been staring at this picture for a few hours and for the life of me I cannot figure out how you laid up the carbon fiber. Did you use some sort of cf tape or did you drape wet cf sheets around the core?

[m_68]

When you apply wet-of-resin-and-agent carbon fibre texture on any surface, and aligned by a brush or a paint roller-like instrument made of different size washers, then it STICKS to it, unless you choose a too curvy surface to apply. The texture will SURELY bend in one direction, like wrapping around everything round edged, for example a tube.
Then there are several processes to laminate it, the one what Brano described is a very effective and cheap solution. If you plan to apply carbon fiber (or glass fiber, or texalium) texture on a surface, you may do the same punch-made-holes method on 0.2-0.5 mm thick film, and then somehow pull it on the treated surface.

[classtopher]

That is just about the coolest thing I have ever seen. Good work.

[FruitbytheFace]

Wow. Nice frames. How long does it take to make one of these? Im planning on making a BMX like this.

[MoritzB]

Wow, this looks very professional! But how you installed the derailer of the gearshift at the bamboo rod below the seat?

[ll.13]

Wow! I always thought carbon fibre bikes were *very* exotic, and not something made in your house. =)

[1qazxsw2]

Carbon fibre items actually take very little skill to make. Most offshore production carbon fibre frames are made by virtually unskilled labour. You've bought into the marketing, my friend. A high-end brazed steel frame takes far more skill to construct. ..not to take away from this at all. Molds take skill to make, as well as, coming up with a practical home method for construction. I just mean that once you get a basic technique down, a trained monkey could actually lay out the carbon layers and resin. The markup on production carbon frames is ridiculous. Likely why you can find carbon frames on eBay coming from Taiwan for a few hundred dollars. (Very often made in the same factory that fancy Colnago frame was made.)

[nicksalt]

Labour is usually the biggest cost in any business, carbon fibre layup is very labour intensive, much more so than welding. Welding can be completely automated, layup cannot. Carbon fibres are very expensive to make. I do agree that the frames probably come from the same manufacturers, however I'm sure the Colagno, etc. frames use higher modulus fibre and more and thinner plies around critical areas.

[Viney3]

a most excellent idea and a beautiful finished product... Has inspired me to try the same thing for a road bike frame!
Was just wondering how much CF cloth you needed to make the full frame? and what you used as a template for the bottom bracket shell and head tube?

[rudi.carfell]

Hey, Big thumbs up for your bikes... I'm Miro from switzerland and I'd like to build one to: http://bambusrad.blogspot.com My question is which diameters have you used and how did you get to them? I see you haven't heat treated your wood, how it's advised on the instructables here on the website. What persuaded you to do it not? It works, don't it? And could you write me a link or something where you bought you polyurethane foam? I would be very thankfull(y(?))... I'm sorry for the bad language.. :) Greez Miro

[jordan.pollard]

I was just reading this thinking, "This looks like Brano's stuff", then noticed the BME on the bike. As always, I envy your bikes Brano! _jp

[bhale1987]

Where did you get the foam rods?

[ZeroTruths]

He made them by using foam blocks and cutting it with a hot wire foam cutter.