Hot on the heels of the first Bamboo Bike post comes this short one for Bamboo MK2.
Design & Build
Using RattleCAD I resigned R’s frame. Using the replacement kit I set about building. This time however I used a less sticky messy method to form the ‘lugs’. I got the idea from Calfee Design’s DIY kits. I used pre-impregnated casting tape. It hardens on exposure to water. You can dip it and squeeze or wrap it on ‘dry’ and allow the moisture in the air to harden it; I tried both methods, they both work equally as well. From my initial experience I’ll go with dry in future but then wet my gloved hands half way through as the epoxy begins to get sticky. You have about 5 minutes to work the roll of tape before it goes off.
I then sanded down the lugs to remove the odd fold of tape or where necessary simply cut any excess off with a Stanley.
Calfee then used body filler for any voids and prepare for painting. I however used the epoxy from the kit. I’d bought red tape but on curing this went a day glow pink. Not what R was after. So I purchased an epoxy colour – signal red. Wow! The colour was great and the advantage of using epoxy over just a filler was it soaked into the interstitial spaces of the tape weave which I expect has made it stronger overall . Final coat covered most of the tape texture. I grabbed the clear coat spray and gave it several layers, then realising it was satin not gloss so it took a little of the vibrant red edge off.
Finish & Ride
With no time to get some gloss clear coat (shops had closed) I dismantled the original MK1 and transferred it all over to Bamboo MK2. New cables done and it was ready!
The following day R tried it out on the Randonneé 100km Brevet Populaire organised by Audax Club Bristol member Izzy.
Verdict: “it’s really good, I really love the red!”
Observations: no toe overlap so more confidence on the hills; lower BB so R is on and off with ease and not teetering when stopping.
Just need to get my old rack modded by the welder down the road and we are good to go for the summer!
What cyclists doesn’t yearn for n+1? Bamboo MK2 was created to solve the issues of the first; it is a tourer and general use bike. The internal hub gear is excellent for this but is like a brick! Plus I’ve probably over engineered the ‘lugs’ looking at other bamboo bikes. R wants to go further and faster. As such I’ve started designing ‘The Red Rocket’. Wheels are built; with a little help 😀
Carbon forks acquired. I’ll use an old 105 11s cassette I have that has seen only slight use. Cranks will be from MK1 as I purchased the next length up for MK2. Carbon seat post from a bike a rarely use any more. I have just enough bamboo from the previous kits left over, these err on the small and light side which is why I didn’t use for the tourers but will be perfect for a racer. I intend to reuse the dropouts & BB shell from the MK1 if I can cut them out of the epoxy.
10s cassette £20.99 – Tiagra 11-32 (depending if a 10s RD is donated)
11s MTB to Road cable pull adjuster £29.99 – JTek Shiftmate 8 (depending if an 11s Road RD is donated)
And this is where I’m on a begging mission. I’d prefer not to do this as there are people out there with much more worthy causes and needs. But at the moment due to changes in life circumstances I’m unable to fuel my son’s passion further. So should you think that this is a worthy cause I’ve created a pool for people to chip in.
All parts can be reused as I intend to upsize with bamboo frames as R grows requiring just new rims and spokes for bigger wheels, cranks and handlebars. Any help towards parts, or donations of similar (please comment below), will be much appreciated.
A while back I’d come across Calfee Designs. Their bikes looked amazing! Then I plonked ‘bamboo bike’ into the Internet and let the cogs spin. They’d been around for ages and came in many shapes and sizes, adaptable to the application, most sensible but some crazy. I also had an idea for a green machine (still just an idea) and thought bamboo would be the ideal material because of its credentials.
From the search I also came across the Bamboo Bicycle Club (BBC); I wanted to go on one of their weekend courses but couldn’t find the time.
Then came LEJOG. Up to now I’d been using my 1984 Claud Butler Sierra. This was my first road bike and my workhorse. It was getting tired. It was worn out. And it wasn’t ideal for loaded touring as the frame had no fittings for racks it was a bit whippy. R was fast out growing his Islabike, a well proportioned steed for a kid’s geometry. So I decided to make bamboo ones to my spec. First I went about determining all the components I’d need. Then measured my bikes for reference and all R’s dimensions I thought would helpful: height, inside leg, effective leg length. He was growing quick so allowed some growing space for the future, from this I determined his crank length.
I got hold of the BBC and ordered 2x home kits with custom design having given every dimension I could think of: the components, the purpose of the bikes (tourers) and all the extra add ons.
Then I waited.
I go about ordering. The first wave arrived, the running gear; rims and hubs. Alfine 11 and Shimano dynamo for me with 622ERD (700c) rims. Nexus 8 hub and 507ERD (24″) rims for R. I also sourced a rollerbrake for him but quickly realised this was unsuitable so upgraded to an Alfine 8 hub for discs. This was tricky as it needed to be 32 spoke holes to match the limited supply of available rims of decent quality in that size; eventually finding a great price from an obscure online German shop with the aid of translation. I also had an old Shimano Deore XT disc hub for the front which needed a new axle and bearing cones. With all components in hand I went about measuring and ordering the spokes from Ryan Builds Wheels and picked them up a few days later from his new workshop.
I’d spent a long time planning the wheels. Both mine & R’s would use an internal hub gear (IHG) for the ease, the ability to change gear whilst stationary would be incredibly useful especially for R as kids don’t always plan in advance when they stop, for me being able to do so whilst fully loaded seemed a no brainer. The rims I chose for mine also had a 3mm spoke hole offset, know as asymmetrical, this along with the dynamo for the front meant I could build my wheels with zero dish. This makes for strong wheels ideal for loaded touring. The spokes for each wheel would be the same length and at the same tension either side. R’s had to have some dish as like I said, quality rims at that size are hard to come by, and after scouring the Internet I could not find any offset. Anyway he wouldn’t have as much weight on his.
Once done I order most of the other parts and continued to wait for the bamboo. I gave them a call and they apologised for the delay. They said they had reservations about R’s design. I said he was a growing lad and with all the dimensions supplied it should be OK. In hindsight I should have asked for the design to check, but as they offer a custom design assumed they knew what they were doing, but more of that later.
Part pitfalls (R’s bike):
The light weight Schwalbe Kojak tyres I’d spec’d for had been discontinued in that size. Other options are heavy sods. I bite the bullet and get the last 2 I could find, they were now considerably more than last year being as rare as unicorn shit. I recently purchased another pair of old stock from ebay costing a third of one of them!
Cranks – kid specific short ones. Again the ones I was after had been discontinued and shot up in price. Internet search threw up a set at the original price from DCCycles but with no buy button. I give them a call. He checks with suppliers and can get a set and luckily honours the price even though he won’t make anything from it, diamond!
After another couple of weeks the kits arrived. I’ve got things to do now so don’t immediately make a start. In fact I don’t start until 3 weeks before our depart!
A0 design template
Bottom bracket shells
Seat post tube
‘Braze on’ screws
Glue, epoxy & hemp fibre sheet
2x bamboo beer to celebrate when finishing
The additional ‘braze on’ screws spec’d
What you need:
Large flat surface that holes could be drilled into for the jig
Disposable gloves for epoxy
Brown paper, masking and electrical tape
The Frame Build
Time to get in the workshop. Well I don’t have one, or a shed. So I repurposed the kitchen table.
I started on R’s first. Followed the instructions. About 15 minutes to sand a mitre apparently for a pole to fit. My arse! After hours of sanding I finally got the front triangle done after several days interspersed with collecting R from school, dinners, sorting events etc. and set about gluing it all into the jig. Now the rear triangle. I quickly realised our depart date of the beginning of the school holidays was going to be close so reschedule for the 3rd week (more details).
Any way I complete the first stage of R’s build involving everything in place and glued. Then comes the wrapping of epoxy soaked hemp strips. This was the messy stage. It was very warm so I had to work quick. 6hrs it took from start to finish with all after wrapping with electrical tape for the compression but then it was done ready for the final finish.
I was going to build bamboo forks as well but after the main frame wrapping discovered I just wouldn’t have the clearance for the front disc brake rotor so frantically sourced a fork. There aren’t that many that size suitable for discs with the right clearance for selected tyres and mudguards that weren’t the heavy MTB suspension type, two in fact; some stupidly priced aluminium ones with cheap squashed ‘dropouts’ for some obscure utility bike or some carbon MTB race ones, slightly cheaper but quality representative of price, so I quickly order and wait.
In the meantime I first give the BBC a call to ask for mitre sanding shortcuts. “Oh we use a tube cutter, we can post you one to borrow if you like?”
I do a preliminary assemble of R’s just piecing together the main components. It is looking like there will be some toe overlap; where with the pedal forward your toe catches on the wheel when turned; this is not ideal for a kid’s bike or touring. This combined to give a fairly short wheelbase (small turning circle normally found on a racer). And to top it all off the BB is looking way too high, not far off an adult’s bike. This will result in either R having his saddle too low for efficient pedalling (what you need on a tour) or at the correct height but not being able to put both tiptoes down when stopped (what you don’t need on any kid’s bike). I contact BBC, they haven’t taken into consideration all the components which I’d spec’d!
Back to mine, with the tube cutter in hand I start. A few hours and the main triangle is mitred, sanded and glued. I sort of lined up the Surly Long Trucker Disc fork I’d be using and mark an approximation of where the axle will be, then measure the wheel base and other dimensions as best I could. The wheel base is fractionally shorter than my Claud’s with the chainstays slightly longer; it’s looking like toe overlap again. I adjusted the rear triangle layout to put the dropouts further back along the apparent axle line; this wouldn’t affect any toe overlap but the longer the wheelbase the more flowing the turning; plus I would avoid any heel rub on the panniers without having to mount them behind the rear axle (this can lead to the front end lifting on hills). That mod done I complete the rear triangle and glue it all into place. One day to do, much quicker! Next day and it is wrapped. That was the hardest day as I chose probably the hottest of the year and the epoxy was beginning to go off in about 15 minutes instead of 25-30. Sticky!
That evening, 13 days before depart, I had an issue. Removing the frame from the jig I unwrapped the electrical tape. Then I had to remove bits of the jig plates. The wooden discs from the BB were well and truly stuck so I par them off with a Stanley knife. I inadvertently slip and throw the blade straight into my thumb. A neat cut. A few seconds later the blood comes. I know it is deep! Grabbing some toilet paper I make a wad and wrap it tight with electrical tape and head to A&E; on my bike of course, my 1953 Raleigh Sports as I’ve removed the tyres from the Claud to use on the bamboo.
Cycling through town with my hand on my head to keep it elevated, blood oozing out and down my face a car passes. I see the passenger staring out the window. Later I pull along side at some lights. “He has, he’s chopped his thumb off!” I hear as they pull away. Not quite but the amount of blood would certainly have given the impression. It’s Friday night. I expected a wait. 3hrs pass before I have it stitched. They’d need to be removed a week Friday, the day before our depart!
Next day I clean up the frames with one thumb bandaged up. Most would sand down the epoxy lugs for the final finish. I start but soon decide not to as the green credentials were at risk with epoxy dust flying everywhere so keep the raw look. Give the frames a spray over with clear coat to protect against the rain and hang to dry for a day.
Nearly all the odds and sods have arrived and I go about the proper assembly.
We do R’s first. With headset in place properly, everything tightened up, cranks, pedals and toeclips on the toe overlap on his is very apparent even without the mudguards fitted. I fit his rear rack. There aren’t many for 24″ wheels but I find one that is adjustable up to 700c wheel and disc specific. There is just a few days now before we depart. I didn’t need a disc specific rack as the callipers are below the rack mounting, this and the lack of space for the rack mount eyes puts the rack high and wide which we find out on the first part of our LEJOG adventure amplifies the poor design dimensions. I ditch the rack entirely once we get back to Bristol.
Then mine. It goes together well. Fitting the rear rack and mudguards was a faff due to much of the dropouts having cutouts ‘to save weight’ (the least of my problems). I settle on using mudguard brackets for a QR mount by drilling them to fit the rack bolt. Forks in place wheels fitted. I was right. Even though I’d specified all the components I had toe overlap too. I’d guessed that, so was using my old 35mm Marathon Plus tyres from my Claud, I’d returned the 40mm Marathon Plus Tour that I’d hoped to use.
I send an email to BBC expressing my disappointment about both of the custom designs hoping they’ll learn from it. My main point was the design template you are provided to lay the jig out with. It is self referencing with no datum. It needs to show intended forks and their rake, wheelbase, BB height etc. Being a custom design I think this is imperative. Digital mock ups to be provided before hand for checking would be ideal so any customer concerns can be raised. I was too trusting in their design credentials. So if you do fancy a Bamboo Bike and want a custom design be warned; see the designs, make sure the dimensions don’t just reference the frame but a datum that you can compare with your own bikes, check your specs have been incorporated etc etc.
The kit? I can’t fault it for what it is, some of the sundries were missing but posted on when available. Instructions were clearish, the mitre sanding was a little misleading. The jig did what was needed. The satisfaction of building something from scratch with just a few hand tools immense. The epoxy, well it’s epoxy, and I’m sure anyone who has worked with it knows it’s a sticky, filthy, but necessary, mess and does the job. The frames were light (mine slightly heavier than my 531 Claud) and stiff yet comfortable. Bamboo has a comparative tensile strength to steel weight for weight. Volume for volume it is less but as it is so much lighter the poles are thicker and thus comparative. Obviously they sound quite wooden when you knock the frame though.
The design? Well I’ve already mentioned my concerns regarding R’s BB and our toe overlap. Additionally I’d personally look at a larger front triangle on mine with a taller head tube.
And the build? I went for some high end stuff where needed like the IHGs, racks, forks, brakes etc for the parts doing the ‘work’ and cheaper for things like handlebars, seatposts (perhaps I should’ve spent a little more to save some woe on this one). As R grows and eventually needs a larger frame I’ll use the good parts and rebuild his wheels with larger rims; and front dynamo as he wants one of those for night riding.
Aesthetics? Whilst raw and unpainted they still look good and turn heads. I’m constantly having to chat with people. Quite a few don’t believe it until I tell them we’ve ridden the length of the UK on them fully loaded!
The follow up – the reason this post has taken time
After that email with advice for BBC we just got on with it. Did some 100km Brevet Populaire Audaxes, little trips, about town etc. R would ‘grow’ into his bike. But would he? Every time he grew, the saddle needed to go up too. Getting his tiptoes on the floor remained elusive.
We did a few days over to Pen y fan in the Autumn half term. He took a tumble on a steep hill because of toe overlap. Both our bikes’ mudguards got stuffed with leaf litter in minutes when using a canal path; as the clearance is set to virtually nothing it is nigh on impossible to effectively clear them. I’ve fashioned a tool now – I carry the end of a sturdy 12.7mm wide cable tie!
Every time he stopped he’d have to wobble from side to side over the saddle. Fine if you are messing about at home on an older sibling’s bike, but not every time you stop on your own bike when you are doing long distances. This continues. It isn’t safe. I adjust his saddle lower for about town at home as whilst it was spec’d as a touring bike it was also spec’d as his normal every day bike. However at a busy set of lights he gets his weight distribution wrong and goes the wrong way spilling onto the road next to me. This frame isn’t fit for purpose with the potential of being dangerous.
I contact BBC again seeking a replacement kit to rebuild. I send a load of photos as requested and wait to hear back. In the mean time he’s done his first 100 miler and ridden back from Snowdonia; both have their moments due to these identified problems. Still no reply after the latter. I give them a call, it rings out, later I get an email.
Basically James of BBC has replied explaining the whole frame is wrong because of the components I’ve used; I spec’d for a touring bike and used MTB parts! Well any one reading this with an ounce of bike knowledge is probably now intrigued. Firstly from the outset I’d spec’d all the parts, wheel & tyre size etc. Secondly the forks I’d selected mitigated to an extent the BB height problem had I used his recommendations. Thirdly 24″ road vs MTB wheelsets are comparable in size using a large rim small tyre vs a small rim large tyre respectively.
To me his email read as case closed and an abdication of responsibility response. I replied. I outlined everything and referenced the emails we had. Including the one where he admits he should have taken the time to check his BikeCAD calculations and apologises for the mistake. The next day I get another response. Apparently James’ finger waving was to open a discussion; I thought that had kind of been opened several months ago after our LEJOG adventure. He goes on to lay claim to helping 1000s of happy people build bamboo bikes, I don’t doubt that, but perhaps the customer service needs to be improved for when things do go wrong and responsibility for ones mistakes are humbly accepted rather than trying to blame someone else with ridiculous accusations. I call James and we have a chat to sort things out.
Outcome & Future
I’ve accepted another kit to rebuild R’s frame ready for this Summer’s expedition. Requesting the BikeCAD design to manipulate myself James tells me there was a break in and his computer stolen with all historic designs. So I redesign using RattleCAD, an opensource frame design program similar to BikeCAD.
I’ve also sourced a supplier of bamboo for future builds who are au fait with bike builds. I’m going to try a different wrapping technique. I’ve had a chance meeting with a metal working guy who collected a load of topsoil from me; he loved the bamboo and has love of bikes too so I’ll consult him for any lathe work. Found a local water jet company for future dropouts with the help of Chris an ACB member who was able to convert the dropouts from the replacement kit into CAD drawings. I’m now in the middle of building R’s MKII tourer frame, in amongst house renovations, once done I’ll build him a faster bike too when I have time – fork sourced and hoops are ready to go! Perhaps redo mine to get rid of my toe overlap and for a bigger frame? My old Claud is stripped awaiting for a complete overhaul requiring some tlc at Argos Cycles; but then again for the cost of that I might as well make a bamboo audax bike too. Then there is the green machine, it’s all in my head, I just need a workshop…