The chaps at the Bamboo Bicycle Club in London are demonstrating the power of 3D Printing and bamboo during a Future Bike Live challenge at the Design Museum. Check it out at Kickstarter:
How cool is this? There’s some great simple innovations in the frame building kit here. I hope it gets funded!
A while back my awesome LBS gave me a box of carbon tubes and lugs and said “You’re the right person to give these too!”. And with that I had 4 frames to build, one of which I’ve completed. Take a squizz:
The process wasn’t a simple one. Here’s what I did:
- Bonded all carbon tubes and dropouts together
- Sanded and filed those back.
- Drilled and riveted front derailleur clamp
- Drilled and set water bottle bosses
- Drilled custom internal cable routing
- 3D printed custom rear brake boss
- 3D printed cable stop for front derailleur cable
- Masked and handpainted the colour stripes with enamel paint
- Flat black enamel spray followed by 3 coats of gloss enamel spray.
What does this mean for bamboo? Well, I don’t know at this stage. It’s certainly easier working with full carbon, pre-made tubes! Maybe there’ll be another bamboo bike made soon… only time will tell.
Today my 4th frame, the recently finished The Samurai, underwent my quality assurance testing that I do on all frames. The video below details the test and shows that the frame is strong and passes the Australian Standards for Frame and Fork Assembly. Stay tuned for a time-lapse of the parts build!
The Samurai, my fourth frame was going well until I discovered that the seat-tube had developed some cracks around both the bottom bracket and where the seat-post sleeve inserts into it.
Luckily I hadn’t yet carbon fibered up either of those joints so I’ve been able to cut out the offending tube and will replace it with one that’s hopefully not so prone to cracking.
The cause of the cracking is probably due to the consistent cold temperates in the workshop overnight and that without coatings of epoxy bamboo will naturally dry out and become brittle and crack. It’s also due to the steel seat-post sleeve insert changing temperatures at different rates to the bamboo, causing the bamboo to crack.
Interestingly both the cracks were in places that would have been covered with carbon fiber and they probably won’t have propagated any further, but I couldn’t take the risk of that not being the case and don’t want to let a mistake roll out the door.
Below are some pics of the cracked seat-tube both before and after I’ve cut it out. It was interesting to see the different levels of adhesion (or lack thereof) of the epoxy to the various materials. It’s mostly only mechanically bonded to both the steel and the bamboo, making it very important to roughen up the surfaces to ensure a good bond. The aluminium bottom bracket is painted in a specific etch primer (the white paint), but it doesn’t seem to have chemically adhered properly to it. I’ll have to investigate why!
Bamboo Bike #3, dubbed The Panda by its eventual owner is nearing completion. I’ve laid up 95% of the carbon fibre and just need to do some final cosmetic layers and then lots of finishing. Then comes the tricky things like brake holes, derailleur mounts and cable stops. Then some clear coat, then some testing!
Bamboo Bike #4 isn’t far away either. The head-tube’s been wrapped and the rest is scheduled to be done next week.
Here’s a few progress pics of The Panda:
We’re investigating setting up a space to run bamboo bike building workshops in Melbourne this winter (the best time to build!). If you’ve got a spare 5 minutes we’d love you to respond to a questionnaire on how we should run these workshops.
Start the Bamboo bike building workshop questionnaire
I’ve been hard at work on the 3rd frame and it’s almost ready for tack gluing in the jig. The 4th frame is very similar to the Panda so I’m going to make them in parallel, which should hopefully cut down some of the labour time. Here’s some pics.
I’ve also had Daisy back in the shop and am in the process of sanding back the finish and redoing her with a UV protective varnish instead of epoxy resin. This should protect the frame for a lot longer and prevent fading and cracking.
I’m using expanding filler foam on this frame as lightweight way to make the joints more curvaceous (and thus stronger). It’s super easy to sand back and shape and doesn’t take long to set.
I’ve done the initial wrappings of the rear end and head-tube with 12K carbon fiber tow. So far it’s taken 90metres of the stuff! I’ll cover these in 1-3 layers of woven carbon fiber cloth then 2 layers of clear coat. Job done.
There’s something very sexy about lasers. Besides being commonly attached to sharks they’re also very sexy in that they can cut through 6mm stainless steel like it’s butter. That’s right folks – the drop-outs I designed have been laser cut by the good folk at New Touch Laser and delivered to my door. I’ve got 10 sets cut, which means there’s a run of 10 bamboo bikes being built in the very near future!
Here’s some pics of the drop-outs, me tapping the thread for the derailleur screw in and how they’ll integrate into the bamboo chain-stays:
I decided to splurge out on a better jig, as the home-made setup I was previously using was a bastard to adjust and get everything level and straight. So I ordered some Maytec aluminium extrusion and components and now have something that’s a lot easier to work with! Here’s some pics of the new setup: