Here's the story of my Bamboo Gravel Bike!
What made me decide to build a bamboo bike?
The initial inspiration came from an article in Cyclist - Off Road. And I fancied doing something new during lockdown. The idea of learning more about how a bike is put together, making something and developing new skills all added to the appeal.
Starting the build last winter, I wasn't sure if I'd be able to actually build anything. My day job involves me running a department of Surveyors and Survey Engineers and whilst their job can be very hands on, mines has been taken up with budget's, sales quotes and a lot of meetings!
Front Triangle Tacked / Sizing up Rear Triangle
But soon I realised that this was exactly what I needed - An excuse to put on my overalls and start working with tools, tapes and plans. This proved to be very therapeutic - I made mistakes and I got things wrong. I also learned and developed patience. I also got to know my downtube, from my headtube, from my seatube. I learned what "stays" were! As much as there was a detailed manual to follow, YouTube guides and a willing accomplice in James from Bamboo Bikes, there always seemed to be a something new to learn and that proved to be the most fun. If you've an interest in understanding how a bike is put together then I can't think of any better way of learning that than to try this.
Flax / Epoxy Bind Process
The Build Process The build itself started with the setting up of the jig. This appealed to me as it was similar to work I had done as a surveyor. Measuring up and positioning headtube, bottom bracket and seat post connections was interesting. My subsequent attempts at fixing them and making them stable enough for the entirety of the build was entertaining!
Frame "Struck" From Jig
With the jig in place I could select my bamboo for the the frame. You build the front triangle first. The phrase "measure twice, cut once" was circling in my head repeatedly as I nervously made the first cut. And of course I was waaaay to cautious with that resulting in a extra hour's sanding as I removed the excess before I could finally begin shaping it. That said tho', I found this to be relaxing and took to pouring myself a beer, putting on a fun playlist and then picking up the sanding block.
Initial Filling and Sanding before Painting
Once you've formed your front triangle, you have to tack it together using a mixture of epoxy and sawdust. This involved the use of wooden stirrers handily available in coffee shops, and coffee cups to hold the gooey mixture - also handily available in coffee shops! It was messy but satisfying to see the gaps closed and I was surprised just how strong the connection felt.
Next up was the rear triangle which consists of your chain stays and seat stays. Again the same process of measuring twice, cutting once was followed by sanding and shaping to the connections. There was also the added challenge of bending the drops outs and then cutting a slot within the chain stay for them. I kinda enjoyed putting the drop out in the vice and gently "persuading" them into shape with a camping mallet. Must have been a stressful day, that day! Joking aside, this is a task that you can get wrong, but by using a protractor from my High School Maths pencil case (took some finding!) I was able to get the correct angle.
Frame Painted and Finished - Ready for Components
Once the slots are created you can attach the chain stays to the jig at the rear wheel end and start tacking the rear triangle. Cue repeated visits to the coffee shop for stirrers and cups! Then you are ready for the smallest pieces of bamboo to be added to your frame. They also can prove to be the most crucial. The brake bridge and chain dampener sit immediately behind your seatpost and provide stability to your rear triangle as you are dropping those "Watt Bombs" going for that KoM on Strava or sprinting for the traffic lights on the club run. Pretty essential. Their position in your frame is essential too, if you get that wrong then you could be struggling to get your wheel / tire choice to fit in the frame. Be careful.
A few Hope and Crank Brothers touches
With the front and rear triangles tacked it was time for the flax binding of my mitered joints. This is by far the messiest job of the whole build. It's crucial to be as prepared as possible. The area you do this in should be clean, tidy and close to a sink. Keep plenty of spare pairs of gloves and rags handy. Before you start binding, you cut all your flax strips to length and get your epoxy mix ready. There is an order of binding laid out in the manual and and a timing schedule to follow. Once you have applied flax / epoxy binds to each area you compress each of them with electrical tape. Note that you should so this with the sticky side up. Doing it the other way results in a poor finish to the binds.
Ready for the first ride
Once the tape has been in place for around 3 hours, you can then begin to remove it. Much will depend on the environment you've left the frame in but in a room of 20C, 3 hours is about right. Don't leave for more than 24 hours as the task will be far more difficult with the glue fully hardened.
Once all the tape is removed, you are then ready to strike the jig and remove it from the frame. Here the use of a camping mallet, chisel and hammer and even a craft knife can come in handy. Make sure you've loosened the wing nuts before hitting anything! After 24 hours and the glue is fully hardened you can remove all the masking tape that was in place and take a look at the frame you've created.
It this point the frame is ready to ride!! You may though feel like you want to add a bit of colour to it, paint the whole of it or in my case try a hybrid of expose bamboo and paint. I decided that I would paint over the joints to add a little colour. In this I was greatly helped by my local Autosave who advised me on sanding, primer and paint.
I had good fun filling and sanding with Dolphin Glaze and then turning the spray paint on it. It was almost like a crash course in bodyshop repair and I ended up watching a good few YouTube videos on taking out scratches and dings!
Once I had completed the paint job, I enjoyed researching the components to add to the frame and was pleased to get some "Electric Blue" Hope Discs and Crank Brother's eggbeater pedals to match the frame. I had considerable help from Steve Ross at REM Bikes to mount the components, but on my next bike build this is where I'll pick up some new skills.
How does it ride and would I do it again?
The finished bike rides super smooth and the rumors I had heard about the dampening effect of bamboo would appear to be true so far. I'm planning to ride it during the whole the upcoming "Nevising" Fundraiser for SAAC. If it holds up during that then I'll be a happy boy. If I hold up during that then I'll be a surprised boy!
If I could change something about the bamboo bike, it would be to modify the stays on the rear triangle so that they could take a bigger tire. I'm running 700c x 35 at the moment but would've loved the option of a 42 or 47mm tire in there.
Something for next time!
I hope you've enjoyed my account of building my own bamboo Frame. Scottish Adventure Cycling are in talks to hold a members only Bamboo Bike Workshop Build Event, so stay tuned for more on this subject
Test Ride in Hazlehead / Den Wood!