Instructables

Step 7: Building up the joints/lugs

Picture of Building up the joints/lugs
Bamboo Bike #2 008.jpg
Bamboo Bike #2 009.jpg
Bamboo Bike #2 010.jpg

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:

http://www.youtube.com/watch?feature=player_detailpage&v=laubuki0Hrw

http://www.youtube.com/watch?feature=player_detailpage&v=2hOBlqscz1Q

 
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Tyler53 years ago
So do you not compress you joints after freshly applying epoxy and stuff?
BAMBOOBIKER (author)  Tyler53 years ago
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.
zakiuz4 years ago
can i use any type of bamboo ?? or i need a special treatement ? if so can i do it home 
immigrantul5 years ago
Hi Eric,
Nice job again...The carbon is awewsome just like you sad.My first try with hemp string was a fail,but now with carbon I am really happy.Your instructable is probably the best for a project like this.One thing I discovered really helpfull about wraping is to put carbon fiber on an empty fishing line role and than start wraping.this way you can go continuosly all the way for one wrap without stopping.I hope this will help you in exchange for all the help you give me.
BAMBOOBIKER (author)  immigrantul5 years ago
Thank you!  You are right the wrapping the carbon around, well anything really, an extra small piece of bamboo works well too, helps keep tension on the wrap as you are manuevering around the frame's ins and outs.  I want to see photos of your project!