Bamboo / BBS02 / Nexus IGH

footloose · Nov 16, 2015

Have begun a project to build a bamboo-framed mid-tail bike with BBS02 750W and Nexus 8 IGH.

Wanted to build a bamboo frame for several years. Got the necessary bamboo for tubes back in 2013. It’s been air drying since then. My gut instinct is that bamboo has ample strength for a mid-tail design (stretched about 5 inches), but I'm less certain about how it might do in a long-tail design. So I’m taking a shot at building a bamboo mid-tail.

Found two steel frame salvage bikes – $20 each – as donor bikes for necessary frame bits.

I’ll document build process here. With luck I’ll end up with a ride-able bike that addresses design needs. Or the project simply may not work out but I’ll have learned something in the process. If the bike feels good I’ll ride it. If it feels like a deathtrap I’ll recycle the frame into garden stakes next spring :lol:

Step One. Selection of bamboo begins the curing process in 2013.

Step Two. Donor bike and dropouts held in place on temporary plywood building frame.

Closeups of the bottom bracket secured to frame and original + new dropouts...

View attachment 2

Step 3. Donor bike with un-needed bits removed and recycled. Key bits remain in original spatial relationship on the building frame.

Step 4. Bamboo tubes tacked in place with West Marine epoxy. Starts to look like a bamboo bike...

Enough for now, more later.

footloose · Nov 16, 2015

Project is coming along! Starting to believe this may turn into a bike someday soon.
Frame assembly went well. Bamboo / hemp / epoxy is pretty simple to work with.
Think that the joints are massively overbuilt, but better safe than "oops, the fork just fell off."
Did some destructive testing on a sample layup (not shown), couldn't break it short of sledge.
Rather than show entire process, here are snaps of evolution of one joint and a snap of full frame as it stands.

View attachment 1

footloose · Jan 29, 2016

"Finished" today. Realistically I guess they are never done... already planning couple tweaks. Pretty happy with result so far.

footloose · Mar 29, 2016

Reserved for next set of tweaks...

wineboyrider · Mar 29, 2016

spinningmagnets · Mar 29, 2016

Well done, sir!

WoodlandHills · Mar 29, 2016

Very cool! What species of bamboo did you use, do you know? I have a bamboo hedge and I've saved a number of 12'+ poles that have dried nicely and are very strong. Having traveled in south east and west Asia since I was a teen I have some amazing things done with bamboo and twine. I wonder if I could harvest some more poles of the correct diameter in hopes of making a longtail cargo type bike next year using your method?

How does it feel as you ride it? Different to steel or alloy?

footloose · Mar 30, 2016

spinningmagnets said:
Well done, sir!

Thank you! Pretty happy so far. Tried to keep it clean,
with minimal reliance on zip ties and velcro in final assembly.
Resulting bike looks a lot less bodged together than any of the
straightforward conversions I've done in past.

WoodlandHills said:
Very cool! What species of bamboo did you use, do you know? I have a bamboo hedge and I've saved a number of 12'+ poles that have dried nicely and are very strong. Having traveled in south east and west Asia since I was a teen I have some amazing things done with bamboo and twine. I wonder if I could harvest some more poles of the correct diameter in hopes of making a longtail cargo type bike next year using your method?

How does it feel as you ride it? Different to steel or alloy?

Thanks! Wish I knew the bamboo species, but I don't. Only know that it grew in Alabama, but it looks heck of a lot like the generic bamboo I see a lot of growing in California. Have my eye on a bamboo grove in San Jose for materials for next project. :wink: My guess is that you could probably use the bamboo from your hedge, which would be pretty cool... a bike you actually grew.
Haven't pushed the bike hard yet, still feeling it out, but the ride is terrific. Think that is mainly due to the longer wheelbase of bike (extended rear triangle by 5 inches), partially due to vibration damping of bamboo tubes.

puregsr · Mar 30, 2016

I am envious.
Now I wonder what happened to that paper bicycle?

footloose · Mar 30, 2016

puregsr said:
I am envious.
Now I wonder what happened to that paper bicycle?

Build one! If I did it, you can. Really wasn't that hard.
Only stationary tools I used were a band saw and drillpress, and
that was just for convenience because I had them. Basic hand tools
would have worked for everything, just taken a little bit longer.

Paper bike... guess if bamboo works, paper could work too.
Marine epoxy is tough stuff, think you could fabricate tubes
of rolled up newspaper that would be plenty strong.
Wonder where a person could get their hands on a pile of old
colored Sunday funny papers? That would be a fun bike.

macribs · May 22, 2016

Cool build, a bamboo e-bike. Well that was a first for me. Cool project.
Growing a bike in the back yard

Btw did you put down you costs in a spread sheet? 2 old scrapped bikes, last years bamboo from garden + motor/battery.
Should be doable for even people with severe financial stress. And beat commuting by train or buss. And if you get tired of it, you could always start a new trade as a flute salesman.

LewTwo · May 23, 2016

Very nice work. By any chance did you ever weigh the finished frame ?

WoodlandHills · May 23, 2016

macribs said:
Cool build, a bamboo e-bike. Well that was a first for me. Cool project.
Growing a bike in the back yard

Btw did you put down you costs in a spread sheet? 2 old scrapped bikes, last years bamboo from garden + motor/battery.
Should be doable for even people with severe financial stress. And beat commuting by train or buss. And if you get tired of it, you could always start a new trade as a flute salesman.

I was thinking you could always make bongs to sell at the farmers market!

footloose · May 23, 2016

LewTwo said:
Very nice work. By any chance did you ever weigh the finished frame ?

Subjectively, the finished frame felt pretty much the same weight as a standard steel frame... maybe very slightly lighter.

I chose not to get an objective measurement of exact weight.
Why?
If the frame was significantly lighter than steel frame, I'd always be worrying about that I under-built it and that it was sure to fall apart beneath me as a result.
If it was significantly heavier, I'd always be convinced that I over-built it and was carrying stupid excess weight for no reason.
So having objective knowledge re weight felt like a no-win.

Rode the bike for a few miles yesterday. It is terrific! And we both got home intact :lol:

footloose · May 23, 2016

WoodlandHills said:
macribs said:

Cool build, a bamboo e-bike. Well that was a first for me. Cool project.
Growing a bike in the back yard

Btw did you put down you costs in a spread sheet? 2 old scrapped bikes, last years bamboo from garden + motor/battery.
Should be doable for even people with severe financial stress. And beat commuting by train or buss. And if you get tired of it, you could always start a new trade as a flute salesman.

Click to expand...

I was thinking you could always make bongs to sell at the farmers market!

Woodlandhills, Macribs --
Have been wondering what to do with the pile of bamboo cutoffs... thanks for suggestions!
Looking at the bike... seems like the seat tube could be adapted as a rolling bong.
Existing battery of 18650 cells could power on demand ignition just like a vaporiser.
Carburetion should work well with a little cable activated sliding trap door instead of a finger...
And at a speed of say 20mph airflow would provide a natural ramjet effect.
Not suggesting this is in any way a good idea.
But it is an intriguing one 8)

WoodlandHills · May 23, 2016

footloose said:
WoodlandHills said:

macribs said:

Cool build, a bamboo e-bike. Well that was a first for me. Cool project.
Growing a bike in the back yard

Btw did you put down you costs in a spread sheet? 2 old scrapped bikes, last years bamboo from garden + motor/battery.
Should be doable for even people with severe financial stress. And beat commuting by train or buss. And if you get tired of it, you could always start a new trade as a flute salesman.

Click to expand...

I was thinking you could always make bongs to sell at the farmers market!

Click to expand...

Woodlandhills, Macribs --
Have been wondering what to do with the pile of bamboo cutoffs... thanks for suggestions!
Looking at the bike... seems like the seat tube could be adapted as a rolling bong.
Existing battery of 18650 cells could power on demand ignition just like a vaporiser.
Carburetion should work well with a little cable activated sliding trap door instead of a finger...
And at a speed of say 20mph airflow would provide a natural ramjet effect.
Not suggesting this is in any way a good idea.
But it is an intriguing one 8)

This could make full face helmets a lot more popular, just run a tube to a nasal cannula.......

footloose · May 23, 2016

macribs said:
Btw did you put down you costs in a spread sheet? 2 old scrapped bikes, last years bamboo from garden + motor/battery.
Should be doable for even people with severe financial stress.

I did not. I keep a rough mental track for my own knowledge but never document exactly what gets spent on building bikes. Sort of better not to know when the topic comes up a dinner.

This one wasn't a budget breaker. I already had most of the pieces, recycled them from other builds (BBS02, battery pack, internal hub, seat, etc).
Actual out-of-pocket costs were pretty much for the scrap frames (not much), some hemp fiber (even less), bamboo tubes (shipping cost more than bamboo), a small can of Rustoleum to paint the front fork (couple bucks), some new cables and brake pads (pocket money). Plus the West Marine epoxy, hardener, and filler which all cost *way* more than I expected per ounce but is great stuff and I didn't need much.

LewTwo · May 23, 2016

footloose said:
... bamboo tubes (shipping cost more than bamboo)....

I spent some time looking for sources this morning. I found a couple of place that sold kits but no one selling just the bamboo. Is your source still active?

footloose · May 23, 2016

LewTwo said:
footloose said:

... bamboo tubes (shipping cost more than bamboo)....

Click to expand...

I spent some time looking for sources this morning. I found a couple of place that sold kits but no one selling just the bamboo. Is your source still active?

Don't think so. I bought the poles on eBay few years ago from a lady in Alabama. Can't find her now.
But looks like there are other sources for raw bamboo still on ebay. Search I used:
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR7.TRC2.A0.H0.Xbamboo+poles.TRS0&_nkw=bamboo+poles&_sacat=0

Bought the hemp on eBay from these guys: Bamboobikesupplies (http://www.ebay.com/itm/Hemp-Bast-Fiber-400grams-/301963251055)
Looks like they also sell full kits, but that gets pricy and kind of less fun.

spinningmagnets · May 23, 2016

At first glance, I'm sure a lot of readers might wonder why this would be worth the effort. however, I am certain this is much easier and more cost-effective compared to buying a welder, which opens up a whole new world to garage custom bike builders. The frames where this might provide a huge savings on are: longtail cargobikes, recumbents, semi-recumbents, and any custom designs from your own imagination.

I had a rough time fitting a BBSHD inside the triangle of my most recent bike. If I had been using a custom bamboo frame, I could have designed around that from the beginning.

footloose · May 23, 2016

spinningmagnets said:
At first glance, I'm sure a lot of readers might wonder why this would be worth the effort. however, I am certain this is much easier and more cost-effective compared to buying a welder, which opens up a whole new world to garage custom bike builders. The frames where this might provide a huge savings on are: longtail cargobikes, recumbents, semi-recumbents, and any custom designs from your own imagination.

I had a rough time fitting a BBSHD inside the triangle of my most recent bike. If I had been using a custom bamboo frame, I could have designed around that from the beginning.

Ron -- Thank you, really well said. -- Steve

macribs · May 23, 2016

At first glance, I'm sure a lot of readers might wonder why this would be worth the effort.

I think anything that might make more people turn to bike for more of their transportation needs is a good thing. And if the material itself is green, well that's two birds with one stone. Talk about renewable. I hear bamboo shoots up like weed in your kitchen garden.

WoodlandHills · May 23, 2016

Not all bamboos are created equal. The ornamental varieties may not all have the required characteristics you need once dried and cured. I cut some 12' poles from a 20'+ hedge on my property and after two years they had lost about 1/4 of their diameter. If I had epoxied them up a year earlier they might have failed at the joint.

LewTwo · May 24, 2016

footloose said:
Search I used: http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR7.TRC2.A0.H0.Xbamboo+poles.TRS0&_nkw=bamboo+poles&_sacat=0

"POLES"

well fudge! I think I used every other conceivable term. THANK THEE!

footloose said:
Bought the hemp on eBay from these guys: Bamboobikesupplies (http://www.ebay.com/itm/Hemp-Bast-Fiber-400grams-/301963251055)
Looks like they also sell full kits, but that gets pricy and kind of less fun.

I saw their adds and they have a bunch of videos on YouTube. Also they are using double walled tubes (one piece of bamboo inserted into another). I would imagine that makes their frames a lot stronger but heavier and stiffer as well... a bit self defeating.

I am old and slow. My projects tend to take months and sometimes longer to get completed (plus I have a number of other odds and ends to finish). If I get some poles now and place them in the attic then they will probably be well aged by the time I get 'round to them.

footloose · May 24, 2016

Woodlandhills, LewTwo --
Agreed, bamboo is tough / strong / light / cheap / renewable -- all good.
Also biological hence variable and prone to dimensional changes as it ages.
For me personally, the aging process has resulted in my getting both shorter and bigger in circumference over time.
For the bamboo, I noticed that length did not change noticeably as it aged but the circumference did shrink.

I wasn't in a rush so let the bamboo cure for lengthy period before I started building.
Say a year of air drying in garage, followed by a session with propane torch to
heat cure the suface and catalyze (?) the surface sugars (smelled great, like caramel),
followed by another year+ of air drying before I started actual build.

Believe the whole curing process could have been completed in say 6 months and
the bamboo ready to work at that time. At least, I didn't observe any dimensional
or weight changes in the bamboo poles after about the first 6 months.

I've heard that cutting poles to rough length then oven-curing them might be
a reasonable short cut, but didn't try that so can't speak to it.

Bamboo / BBS02 / Nexus IGH

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