Step 7: Building Up the Joints/lugs

Now that the frame is "tied" together, we need to build upon the lugs for strength and rigidity. Recognizing where the primary forces are going to come from and making sure the frame can handle the deflections and torque associated with the style of riding you plan on doing. Now me, I don't plan on showing this frame much in the way of mercy. I will ride it just as hard as I ride my other bikes, it is not going to be a cruiser and it is not going to be a coffee shoppe queen! So, I need to build accordingly!

This means building up the joints in virtually every direction, but especially laterally where I will place a great deal of torque at the bottom bracket and upper and lower head tube. To do this I actually cut roughly 6 inch strips of the string - about 25 of them for each lug. I lay them straight across the joint on the side I am trying to reinforce. I then wrap around the this wrapping around the tube then criss-crossing around say the head tube for instance, creating almost an x accross the front of the tube.

Check out photo number 3 below for this on the bottom bracket as well as photos 4 and 5 for the same at the head tube. This process is repeated time and again while doing some random crossing over as well.

Carbon Wrap Video:



You should totally offer classes on construction of these bad boys -- <br>definitely the &quot;next big thing&quot; I think -- <br>I'd buy one and/or attend a class. <br>
I've contemplated that pretty intently, the class/workshop option. I am working on a couple of things right now with larger scale production options, and actually entering the market with my own line of bikes, aside from the one off customs for clients that I am already doing. But, if there's anyone out there, including you, that desires the one on one assistance in building one of these for themselves, I'm absolutely open to putting together a class/workshop to build a bike. Feel free to ask. I'm in central California.
Haha nice bikes! I have a Felt myself :) felt nine 60 29&quot; x 2.2
Yeah - I dig Felt's bikes! Met Jim Felt one day just by chance, cool guy. Couldn't bring myself to tell him I cut up one of his frames! Although I did give it a second life, so I guess it's not that that bad?
I LOVE felt. I ride my z95, and nine 60 about 30 miles a day. And i live near Irvine, which is where they are based. And you did really good on making that felt look nice XD. If you are near Orange County, California, you should visit a great bike shop. The best in OC. Its called East West bikes. Its a super high end store, but amazing. And Banning (the owner) is a great guy
My brother's in the area. I'll check it out next time I'm down there. Thanks for the tip and good word. Love it when people appreciate their local bike shops! The Internet has given them a huge amount of competition and driven price structures down so much, that it's hard for them to make it. Keep shopping with them!
i dont know what type of bamboo it is :( its some bamboo i picked up one day. it seems to be a thick walled one, and has 'branches' growing out from the nodes. Thanks for the quick reply! <br>and i couldnt reply directly to your msg as my com doesnt show the recaptcha thing we need to fill in
I came across a Cannondale Supersix HiMod that had a broken top tube and seat tube. I cut the tubes out and replaced only those tubes with bamboo. The top tube was replaced with a very small diameter bamboo tube, 1 1/4&quot;. It looks cool, but has also been very sturdy. I have to mention though, that the seat tube has to be large enough to accommodate a seat post. Unless you are doing a fixed post where the seat mounts directly to the top of the bamboo tube?
hi, for the diameter of the bamboo you use for your bamboo frames, if i were to use diameter similar to those of steel bikes, will it still be strong enough?
That depends on the type of bamboo you are using, and the size of the frame. If you are using 'iron bamboo' the absolutely, if something different, maybe?
this is an awesome I too am located in central California and I would love if you hosted a work shop. I'm currently in high school and I would love to start a career in bike building. also have you ever experimented with using hemp fibers instead of carbon fiber? if not you should. thank you just for reading this.
Cool - it's amazing how many people take an interest in this project. It's fun and you end up with a pretty cool and usable product. I was very into putting this together as a business and looked like thins were working out in that direction, but life and other things have gotten int he way over the last year. So, as much as I'd love to do the workshops, and produce bikes as my business a daily job, it's just not realistic for me at the current time... I am always willing to lend a hand when someone needs help. <br><br>And yeah, I've used hemp. It works out just fine, and may be more organic, I just like the look of the carbon - personal preference, that's all...
Hello, I keep coming back to this instructable and thinking I'll give this ago and I think this summer is the time to do it. I've got a damaged frame and found a source for the bamboo etc... I would be interested though how much epoxy you used in total? I've seen 500g and 1.2kg 105/205 sets for sale, which one would you recommend? <br> <br>Thanks again for the instructable! That really is a lovely bike.
I have been using the West System 105 quart resin and smallest hardner setup - seen here - <br><br>http://www.discountmarinesupplies.com/West_System_Epoxy_Prepackaged_Kits.html?gclid=CIX3h7OXubcCFSJlMgodfVoA8Q<br><br>Go with the slow hardner for summer - the fast will harden before you can work with it if its over 80 degrees out.
I just finished building my own road bike, take a look: <br>http://www.cameronbrown.ca/blog/2013/01/how-to-build-a-bamboo-bike-part-1-plannin-things-n-fetchin-stuff/ <br> <br>http://www.cameronbrown.ca/blog/2013/01/how-to-build-a-bamboo-bike-part-2-cuttin-things-n-wrapin-it-up/
Good job, and well written. The jig looks like it worked well for you. You should detail that bit of the build, it makes scratch building so much easier!
Hi, great frame and specially like the lug color! Nice job! I'm toying with the idea of building my own carbonfiber bike and already have all CF tubes taked together with epoxy, but am stuck on how to reinforce the jonts. I would like to use this carbon fiber tow technique, but would like some ideas on what pattern to use around the joint, specially for the bottom bracket. I would appreciate any comments or help with this issue. Thanks!
I PMed you with details and video links. But, quick question from me, where did you get the carbon tubes for the frame? What you are doing, is my next project... <br> <br>Best of luck...
Hi, I will be checking the videos inmediately, thanks!! As for the carbonfiber tubes, I got them from RockWestComposites (http://www.rockwestcomposites.com/browse/bicycle-carbon-frame-tubing) , they have bicycle specific tubesets but no chainstays (only seatstays) although I believe Calfee and Parlee use the 16mm seatstays as chainstays (because their chainstays look too thin) so I ordered them as well (hope this made sense!). I also contacted Joe Bringhelli at www.bringheli.com who has dedacciai carbon tubing, a little lighter than the Rockwest but more expensive, but he can get only the rear triangle for you (Firebox quoted for about $275, I believe). I decided for the Rockwest to get everything from the same place, but now think it would have been easier to use the Deda rear triangle, as it's 2 pieces it's easier to manipulate, center the wheel, and more reasonable diameters, etc.<br>Hope this helps<br><br>Ciao.
I used your instructable to build my first bamboo bike. It is awesome and I thank you for taking the time to make my first attempt easier than it would have been. I am planning on making more and would like to speed up the process by using the west marine epoxy and hardener. The max clr looks nice but, takes way to long to cure. I spent more time waiting for the epoxy to cure than I did building the bike. I know you now prefer to use the west systems 105 epoxy. My question is which hardener did you use? Was it the 205 206 or 207? What did you use for your heat source? I learned a lot on how to maximize my time and speed up the process with my first build. The only thing slowing me down now is the epoxy. Thanks so much for your help. Thanks to you I am now the proud owner of a self built bamboo bike and my wife and friends will be able to join the club too.
I'll PM you...
Good job! I'd love to see pictures! I used west systems 205 fast hardener for winter, and used a set of 500 watt flood lights which generates a ton of heat, as my heat source. The fast hardner is fast though, so keep that in mind! It also heats up in the cup and will melt plastic cups if that is what you use, and you mix too much at a time. I used batches of about 20grams resin to 4grams hardner as it mixes at a 5/1 ratio. With heat, it takes a very short time to set, it would take as little as 15-20 minutes. If it's cold you have ample working time with the fast hardner, but, if it's above about 60* out, you may want to go with one of the slower hardners. Heat will make all of them cure quickly, even the slow hardner.<br><br>Good luck on your future projects. Are you building road frames or mountain? I've abused my mountain frames to great extent, big drops, falling in rivers, bashing it off rocks (I fall down alot), and they just keep on going! Oh, and I'm 6' tall and weigh around 200lbs. It really is amazing how good bamboo is as a bike frame <br>material! And the carbon 'lugs' save the scratches and such, are solid, after 2+ years on my main 29er Mtn bike, and a year and a half on my back-up. My road bikes have many many many thousands of miles on them, and are also doing just fine. Amazing what you can pull off with a little common sense and the right materials!
I have another question for you. Where do you recommend I look for Campy or Ultegra groupsets? I really want to build up my roadbike with good components. Any help sourcing the groupsets at a reasonable price would be greatly appreciated.
Thanks for your fast reply. My first frame has been built up into a beach cruiser as I live at the beach. I will be building my next frame into a road bike. I will post some pics soon. I think I will go with the slower hardener because even though it is winter here, we have been getting plenty of 60-70 degree days. It's amazing how much you can learn from your first build. I learned which tools and techniques work for me. Have you moved onto using a jig yet? Is your business under the radar or are you trying to go legit? I ask these questions because I'm interested in the business side of things as well. I figured going legit would pose some issues, insurance being the biggest. Thanks for your help and your detailed answers. I love to build stuff and this has been really fun and rewarding.
AWESOME BIKE! Why did you leave the original chain stays though? Does it help with the strength?
A couple of reasons actually... First is yes, I felt like it would give me a stronger platform to put power to the rear wheel. The plan was/is to ride many many miles. In fact I've put between six and seven thousand miles now on this frame. While bamboo is plenty strong and durable, on my first bike I really wanted this area to hold up. That said, I found that I really like the look, and have continued to build this way, although it's structurally no more durable than if I'd built bamboo chainstays as well. I like that I can add color.<br><br>Now, more practically, for the home builder, without a jig, this type of construction method makes a lot of sense as well. It is very important to make sure your bottom bracket and rear drop outs line up totally squarely. This can be very difficult without some sort of jig assembly. As some one pointed out, in an earlier message, often times, if you're tearing apart an old frame, some of the tubes you remove may be under a bit of stress, and if you cut it, the frame geometry may <br>distort a degree or two. This degree or two, while not terrible elsewhere, in the chainstay area, this can wreak havoc on your chainline and make for major problems when building up the bike for actually use. And, if you're building s fixie, chainline is very important!! <br><br>So basically, it gives the sense of being stronger, I think it adds to the look by giving me more area to paint, but most importantly, it was insurance for the final build, that the rear end would line up properly.
Thanks for the reply! You have been really helpful and I agree with you that it does make the bike look very nice. Thanks for the help.
Hi, I have a donor bike that has a tapered seat tube and a down tube that is significantly butted at the head tube for strength. I'm not too concerned about the down tube, my thought was to cut the frame a half inch below the butted area and build as directed. So as far as the seat tube is concerned, do I build up a carbon wrap on the narrow end(seat end) of the existing tube to accept a larger diameter of bamboo, or do I taper the inside of the bamboo on the bottom bracket side?
I think I understand the question. You are asking about slipping the bamboo into the existing tubes, or the existing tubes into the bamboo to form almost a dowel type joint rather than a simple butt joint. I've found that you can at the head tube as well as at the bottom bracket grind the existing down tube and top tube all the way away. This leaves you to form a fish mouth with the ends of your bamboo and slip it into place directly up against the raw bottom bracket and head tube. You can 'glue' the bamboo in place with a bit of resin and a couple of strands of carbon to hold it firmly and move on to the next piece. So you don't need the butted section at the head tube unless you absolutely want to keep it. If you do, and you certainly can, you'll want to go with as small-a-tubes as you feel comfortable with (weight savings here). If tubes are large and you can slip the bamboo inside, then do so. Or you can dremel out the inside a bit and slip the bamboo over the tube. Either way will work and I've done both, although I feel it's unnecessary. As for the seat tube - you want your seat post to fit down deeply I to the seat tube, so it's best to have the diameter of the seat tube larger than the post, so it can fit inside. The way I've always done it is by tying the aluminum seat tube into the top tube and seat stays. The bamboo seat tube comes after and thus does not require it to be firmly attached to the aluminum tubing. The aluminum seat tube top actually floats a bit inside of the bamboo seat tube itself. Now it's best to have it tight, because the seat post puts quite a bit of torque on that joint, so if you can and want to, either pick a bamboo pole that will fit snugly around the aluminum seat post, or dremel one out a bit, or yes you can build it up with carbon to make it fit snugly. I hope this all makes sense? You can message me and I'll give you my number if you want call and discuss?
What is the difference in 3k, 5k, and 12k tow? I've even seen 48k. Is one preferable?
This designation tells you how many fibers per strand of tow. The 1k is 1000 fibers and the 12k is 12,000 fibers. 1k is about 2-3mm wide and 12k is almost a cm and thicker. Yes, 6k is preferable, if you can get your hands on it? I say this because it is thick enough to work easily with, but thin enough to wet out easily and not twist up on you so it lays flat while You're working with it...
so when I'm cutting I'm having some splitting about 1/4th of the way through the bamboo and about 1-2 inches long. <br><br>Can I still use the bamboo and just wrap more carbon around this split or will it eventually go all the way through and start creeping down?
My guess, without seeing what you are describing as splitting, is yes, if its a true split, you could see that split continue down the entire tube over time, even if you add extra carbon. While cutting, often times though, you will see what amount to splinters in the skin that will come away from the outside of the stalk. Don't worry too much about these, just take a utility knife and cut them away. These won't usually become cracks. I've had success with wrapping and stopping cracks with carbon as well as filling the crack with resin. But, I don't think it to be a permanent solution...
Hello, Tanks for your instructable. <br>But I have two questions left:<br>Some of my bamboo rods have a few very little cracks. <br>Do you think that I can build a bamboo bike no matter if I use these rods with very little cracks in it?<br><br>Which way of preparing the bamboo is the most strongest? -<br>Hardening it with a propane torch and leave the walls, that comes after each bamboo segment intact - or hardening the bamboo with a propane torch and make a hole into the segment walls and fill everything up with polyurethane foam?<br>Can you say what option is better?<br>Thanks for your answer. <br>Greeting MoritzB
you bike is outstanding! what diameter bamboo did you use ? what carbon tow did you use 12K , 6K ..? <br><br>thanks for the help
So do you not compress you joints after freshly applying epoxy and stuff?
No, no compression needed. You can really pull quite tightly with the carbon tow. If you are building using hemp, or flax, or bamboo fiber, etc... Then yes, you will need to compress the fibers and resin at the joint. Black electrical tape seems to be the way to go to get this accomplished! If you pull too tightly with the hemp fiber, it will tear.
I was looking for resin on that link and I saw that there were different types of resins, you suggested the Max CLR, but would other resins work just as well? I ask because you can buy more for less of some of that other stuff, my suspicion (pardon the spelling) is that the other products aren't as well suited for a bike joint.
Having now tried several types of resin now, my current suggestion, for it's properties and ease of access, plus a solid company and reputation, is West System 105 resin and hardners. Available online and in many boat stores. The stuff is just amazing to work with. Using a heat source I am now able to cut my bike building time considerably, as the West System epoxy cures quickly and fully with heat within half an hour. I can sand, and begin to wrap again with little down time! The max clr takes forever, about 2 days at 75 degrees, before you can sand it without it gumming up your paper, or file! I finished a bike in 1 day with the Weat System system, granted, it was a 12 hour+ day! : )
Thanks! I'll check it out.
Did you notice any change in the bamboo's diameter before vs. after heat treating, or did it pretty much stay the same?<br><br>p.s. Beautiful work these frames, excellent photos/explanations. I cant wait to get started
Very little change at all. Earlier I estimated it as a much greater change than it is. It appears to shrink up visually, but I think it's more of a visual effect as the color is changing. Putting calipers on before and after, we're talking a fraction of a mm. The wall thickness about the same.<br><br>And thank you! If you have any questions along the way, feel free to ask!
Thanks for getting back to me so quick. I have couple more silly questions before I dive headfirst into this beast of a project.<br><br>And they are; were you measuring inner or outer diameter of the bamboo? And if I have a close (but too small) fit, is it safe to shave off a bit (less than 1/8 in.) of the inner core to make a better joint, or does that compromise the bamboo?<br><br>To be honest, I haven't even picked any supplies up yet, but I love summer projects and this right up my alley. Can't wait!
After further studies I have realized you answered all my questions in this instructable. Once again, quite a good instructable.
Hey! Great instructable, I just read through it the other day and now I'm inspired, but I also have a few quetions: <br> <br>About how much total Carbon Fiber Tow did you use? And why did you choose Carbon over hemp? <br> <br>I'm just looking to start small, so could I build a single-speed bike and have the option to make it into a multi-speed later? <br> <br>And what kind of bamboo did you use? <br> <br>
Hi, i just turned Pro of this just an hour ago just to make a bamboo bike for me. i have a question, i don't know all characteristic of resin but are they all have a strong smell?<br>thanks
No, the resin I use in this instructable is almost scentless. I've used it in the house, without my wife's objection. That said, it's probably not a good idea. All resins give off fumes, whether or not they smell. And while I'm not sure, I'm guessing these fumes are toxic. Just saying...
Whats the total weight of the finnished frame? Not the whole bike - that will be pretty light anyway due to your Campa Chorus etc.<br><br>Did you save weight from the aluminium-incarnation of your frame to the bamboo-reincarnation?
My road bike frames are running in the 1600 gram range, and the 29er mountain bike frames are running around 2400 grams. The 29ers save about 200 grams over their original, the road bike is about 150 grams heavier than the original...
Thanks for the info, thats good to know! The only Bamboo-Frame I could lay hands on up until now is pretty badly built, and heavy as f* (seems like something around 2700g - its a road frame). I guess the guy who built it took the next bamboo he could lay hands on. Also he used an excessive amount of epoxy and fabric. Propably because he was afraid and wanted to make it last.<br><br>I'll try my own in the next months based on your instructable and post the results.

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