Some of you may remember this thread

https://singletrackworld.com/forum/topic/new-bike-day-just-need-to-build-it/

Where I built up  a bamboo gravel bike from a kit (Chinese import). Final result was this bike:

https://ibb.co/mqhrMe

Until the wife lent it against a radiator and cracked the top tube end to end!

Anyway, I’ve always wanted to do a mkII and have just purchased a bamboo bicycle club cx kit,  so keep an eye on this thread for updates.

I’ve a bunch of ideas on design / improvments on mki, but any suggestions are welcome.

On the basis of this post I’ve just read the old thread you made!

This should be great to watch evolve!👍

Excellent, looking forward to seeing your ideas.

Rear tyre clearance is the big one. Mounting the seatstays outside of the seat tube is one easy fix. I reinforced the stays with dowelling to get more contact area for the resin but only at the hub ends. Wish I’d done both ends because then you could probably carve some away at the tacking stage before binding.

Yep tyre clearances is a biggy. Mk1 was also quite flexible when putting the power down so I’d like to stiffen the rear end (carbon chainstays?)

Dropped seat stays mounted externaly to the seat tube is a definite. I could make the front triangle first as chain stays is a bit trickier, mounting the chainset and work that out from there would be a solution or integration of a sculpted chainstay bridge.

Also toying with the Idea of carbon lugs, but the additional cost of the carbon is putting me off…..

Easiest way I found to get the tubes mitred correctly was with a hole saw cutter believe it or not. Vertical jig, which you mentioned in your previous post, would definitely help with getting an even wrap. Internal routing again? All internal? That would be cool.

Sculpted chainstay bridge would solve clearance issues at the BB but failing that mounting the stays as far out as possible with the chainset built up as you say (1x?) would give peace of mind before it’s fully built and too late to change.

Will be watching with much interest.

It’s definitely be 1x with a part swap from my charge plug (which was temp replacement from Mk1).

I’d like to do the wrap out of the jig this time if I can.

Rear mech routing im aiming for full internal if I can get the tubing to work (something more flexible than the Ali tube I used last time.).

Project is starting a bit slower than I’d like, I was hoping the kit was going to turn up during the week so that I can get a plan together but it’s a no show….

So it’s a Sunday spent clearing the garage in readiness. I bought some 18mm mdf to serve as a base for the jig – would love to get an adjustable Ali jig but my budget can’t stretch to another 200 for the parts.

Ill just leave a vid of mki here for now.

Tung oil. That’s the other thing I was going to say, for when you get to that stage.

Ok, I got board of waiting for the kit to turn up so I emailed bbbc yesterday and within 30min had a dispatched notification form DHL, and later on an email apologising for the delay.

The kits turned up this morning so I thought I’d do a quick comparison between the bbbc kit (£295) and the bamboobee kit (iirc this was less than £200 Inc import duty, 2years ago).

This is edited and put together on my phone so apologies for spelling/predictive text etc.

Bamboobee kit

Bbbc kit

The Bamboo bicycle club kit, although more expensive is slightly less slick and also different to the Internet pictures. Only small things like the epoxy is in original packaging (I guess a safety measure) and the tubes aren’t nicely wrapped in branded paper etc. So minor – but would have been nice.

The tubes in the bamboobee kit are double bonded, as you’ll see in my original thread and also were pre finished (part of the reason I built that kit first), so you only have a few hours work before the glue stage. Bamboo with the bbbc kit is raw, unfiniahed so there is a fair bit of cutting sanding and shaping to complete before anything is glued. The do provide a spare toptube, chain stay and seat stay though in case things go sour. Im hoping that I’ll be able to use the spare tubes to try out a different toptube and also the spare chainstay to gain mud clearance. The tubes are also frayed on the ends,  from where bbbc have cut them to length. This isnt a bad thing as the effected areas need the top layers removed for the epoxy to bond correctly.

Next, metal work. The headtube and bb on both kits are pretty much Identical. Standard Ali parts. Tge cyclo-cross bbbc kit is avaliable with a. Tapered headtube, but this one is standard 1and 1/8th, I may contact bbbc and see if I can swap for the tapered just for longevity (1and1/8th cx disc forks are very hard to find now). The bbbc dropouts are far superior to the bamboobee kit, propper Ali rather than thin steel and also swappable, the kit comes with horizontal and vertical but bolt through is also available (extra cost – also would require new jig parts I’d have thought).

The hemp cloth in the bbbc kit is also much nicer than the bamboobee, which was an odd flattened rope with a cotton backing. Although I’m still undecided if I’ll invest in some carbon fibre…….

The bbbc instructions is like war and peace in comparison to the bamboobee alternative.

The bamboobee kit does come with a full, albeit a little flimsy, jig. I used a backing to make this sturdier. The bamboobee jig is also fixed geometry. The jig parts with the bbbc kit require a sheet of mdf (not included), so about 12quid but this does alow for flexible geometry, I’ve gone for a standard medium cx build.

The bamboobee kit doesn’t allow for any glue/epoxy and I think these cost me another 25quid or so. Where as they are included in the bbbc kit. This is due to international postage regulations according to the bamboobee website.

Im sure I’ll get into more details as the build starts……

So here’s what came in the box.

Ill aim to sort out work space (in the messy garage) tonight, so for now it’s the living room rug.

The tube on the far left is a good 10mm wider than the headtube and would provide a pretty substantial down tube. One of the the next two will be the seat tube and a spare, the next I’m hoping to split down the middle for a ‘ovalised’ top tube, taking inspiration from the areo build recently shared by bbbc.

Not much progress yet, like I said it’s a much longer build than the last project. I just spent a few hours sorting out a clear and clean(ish) workspace in the garage (yes it was that bad). Laid out all the parts and started to inspect and workout how I’m going to approach the build.

First off was cleaning up the Ali dropouts, these are water jet parts that are supplied raw. So 30min with dremmel and a fine sanding wheel to sort the non drive side. They’ll probably end up being painted black, but I’m better doing it now than when built up. See photo below for the before and after.

Then I looked at the drive side parts…….

And I’m not happy.

The drive side mech hanger isn’t tapped/threaded for a mech! I emailed bbbc earlier in the week regards swapping the straight steerer for a tapered and havent heard back, so another email to them today asking if they can a, send me a threaded dropout and b, sort out a swapping the  steerer tube….

TBH in comparison to the original kit I bought the Bbbc kit seems to have just as many issues. OK it’s a bit rough and ready, but it’s also £300 – the Ali parts although they’ll do the job, arent exactly high quality.

I’ve also noticed that the disc brake mount will be outbound of where it should be (not in-line with the dropout)……. This is due to the design of the interchangeable dropouts (they bolt to the inside of the Ali plates). It can be fixed with a bit of shimming with washers, but again I’m thinking it could be alot better.

Bbbc are going to send a tapered head tube and threaded mech hanger out today – yay.

I’ve also two other exciting packages turning up this week……

1st parcel turned up today……..

On my BBC road bike kit I also had the untapped mech hanger issue. I just bought a set of taps and some cutting fluid…

…I ended up arsing it up and helicoiling it in the end.

As you know, I’m looking at a modded bamboo MTB build at some point over the winter, so will be watching this thread with interest… Especially since I had some crank clearance issues* on the road bike and want to mod one of their 29er kits to fit a 27+ back end (as well as slacken the HA out too).

*comparing the photos on their site I have a suspicion I got supplied with seat and chainstays that were on the thicker end of their tolerance range for road bikes. Or were even from the ‘MTB’ pile…

I have to be honest, it did feel as it the box of bits was thrown together hastily (prob after I emailed them a week after ordering). It annoys me that items like the mech hanger are unfinished and would require additional tooling and cost.

Your road bike kit looks good colournoise, did it take you long?

My chainstays are also on the thicker end of the spectrum, a similar issue I had on my first build regards tire clearance. Im going to draw up a clearance drawing to see what I can do,. I’m quite tempted to try steam bending the chainstay, rather than cutting and realigning.  A bit like a Boo Bikes have done in the past (pic below). Im also using a Mtb deore triple chainset (converted to 1x) which provides much better clearances than a road chainset.

Always interested in these builds!

Another package today….

Right, 1st bit of propper fettling tonight…..again apologies for any predictive text issues (doing this on my phone isn’t great).

I sanded back the drive side drop out, I’m waiting on the threaded  mech hanger  before I can finish that side. But I also mounted up the non drive side with the supplied chainring bolts. The bolts are quite short though,  they only give about 3mm of contact, which I’m sure is fine – but I’ll probably swap them out for longer ones if I can find some

You’ll see from my earlier post that the seattube turned up today. Here’s a pic with the Ali shim test fitted (took a little sanding). Not sure if I’ll be able to prevent corrosion between the carbon and Ali at this junction – so I’ll have to have a think on that……

Over the weekend I aim to get the jig set up, so I went through those parts. Not sure if I’ll modify the dropout mount as it’s set up for 135mm hubs and mine is a 130 disc hub….. I wasn’t happy with the bb mount as there was only a small disc holding the bb in the correct place and this was 2mm too small, so the bb could rattle a little in the mount.

You can see the part just below the bb tube, Here’s a pic of it in the bb – you can see the paper around the disc.

Now I don’t own a lathe so I cut a disc from a bit of 22mm mdf and used a drill and finger sander to get it to fit snugly in the bb. I’ll prob mack another to fit in the top.

Anyway that’s as far as ive got today. Im hoping the tapered headtube will arrive tomorrow. As you can tell it’s a bit Heath Robinson, but I hope to get it to a finish I’m happy with. Oh, I also have made some 6mm shims for the disc brake, but forgot to take photos.

Your road bike kit looks good colournoise, did it take you long?

Cheers. I’m pretty happy with the finish overall and it rides just fine.

I built it a bit piecemeal, so accurate timescales are tricky. I’d say a short day for cutting, mitres and tacking together. Another short day for wrapping the lugs. A long day for shaping, sanding and finishing the lugs. Couple of hours for prep and lacquer. Finally, many frustrating evenings of filing the dropouts to get tyre clearance and trying to sort the crank arm clearance issues.

Next time I’ll definitely be building the rear end with a crankset mocked into place, and some kind of spacer to stand in for the rear tyre…

That’s pretty much 5he time scale of my last one. This one will be a fair bit longer as each joint could take a day of laying up, let alone finishing.

Regards the backend, I’ll do a print out of what I want and lay out the poles to see how I can best achieve it. It’s a pity bbbc don’t include it within their drawing – pretty sure they do with the Fat Bike version as its a bit more complicated.

As I said before I want to try steam bending the seat /chain stays to get a nice curve back into the bb and seat tube junctions.

Tapered headtube has turned up in time for the weekend, which is great. The threaded mech hanger wasn’t in the package though….. May have to try threading it.

I’m guessing bbbc buy in lots of headtubes at max length and then cut them down to size to match the rider. The top edge looks like its been cut with a pipe cutter – rough edge and slightly bulbous.

As I’m using carbon fibre joints I need to isolate the aluminium from the carbon. Carbon fibre reacts with aluminium and causes galvanic corrosion – something alot of the 80’s and early 90’s custom carbon bikes suffered from. I maybe wrong but iirc the carbon essentially causes the aluminium to oxidise where they touch, especially if you get the joint wet (like in a mtb or cx situation). The surface of the Ali becomes covered in Ali oxide (white powder) and the joint debonds. It’s why Ali seatposts get stuck in carbon frames – and why you should use some carbon grease when mixing Ali and carbon fibre parts.

I obviously can’t cover the Ali parts with grease, so I’m going to cover the Ali bits in resin and a layer of tissue fibre (very thin fibreglass) first. This should provide some isolation the Ali from the carbon and prevent debonding of the parts at a later date.

Liking what you’re doing with it, especially the carbon seat tube.

I kept mine simple and it still took six months lol.

Thanks gecko76, I read through your blog – 1st thing I did this morning was to mark the bb with a L for left and D for drive side!! How’s yours holding up with the bb junction?

I did not manage to get as much done as I’d have liked today (out on the mtb tomorrow).  But that’s mainly because I was picking up a wallpaper steamer to make a steam box!

I did manage to remake the round headtube jig parts and put a small hole at the base of the seat tube slot. Annoyingly there was no seat tube glue in my kit! So I’ll but some specific Ali/carbon glue.

I also got the jig together, Ive covered parts that are likely to get stuck to other parts with orange ptfe tape. The head tube has this internally and the bb junction externally due to the threads.

🙂 BB junction is happily taking all the abuse I can give it. Stiff yet compliant etc.

Yours is shaping up well.

Good to hear it’s holding up gecko76!  Must have been a heart wrenching moment when it happened!

I’ve bought some methacrylate adhesive for the seattube. I went with this over a standard 2part epoxy because Id like torun 2 bottle cages. One reason I wasn’t sure about running a carbon seattube (again more work).

This adhesive is formulated for metal to carbon fastenings so I’m hoping I can surface bond two bottle cage mounts to the tube when I bond the seattube sleave.  I’ll then wrap reinforce with carbon tow prior to bonding up the frame. This should give me some practice with wrapping carbon tow as well.

loved the last thread… will no doubt love this one too…

carry on sir!

Quick update (although no photos). Ive not managed to get much done this week, work and racing at the weekend got in the way.

I have, however, covered the bb and headtube in tissue glass and epoxy. I did have a couple of issues – firstly I put a little too much hardener In the epoxy. For some reason the epoxy I had needed to be mixed in a 100/3 ratio, and I only needed a little (50ml?) so putting 1.5ml of hardener in was tricky. It ultimately ended up getting too thick too quick and braking up the delicate tissue glass as it was brushed on.

Secondly I didn’t think I’d do the of the dropouts so didnt prep them, but had spare glass and epoxy so gave it a go. However once the epoxy had cured it haddent stuck to the Ali on all sides so I picked it off again where it haddent adhered. I’ve now roughened and cleaned these surfaces.

Im now ready to get the downturn in possition,  but I need to decide on the internal cable route first. Specificly where it exits around the down tube.

Really enjoy this thread, and the previous, but one thing I’m most impressed by is your persisten good humour despite all the things wrong/missing in your kit – no glue, wrong headtube, wonky dropouts, no threading on the hanger, etc, etc.  I know I’d be well pat the point of sending it all back and demanding a refund if I was in your shoes. Is there frustration behind it, or are you just willing to cut them a lot of slack becasue they’re a small poutfit, and it’s part of the charm?

TBH Im cutting them a chunk of slack, the kit is twice the cost of the Chinese one I got a couple of years ago (the reason I whent with the original one in the first place), and for 300notes you can buy a fairly decent frame. But for me it’s about the experience of building it, stuff like this is a little frustrating and although bbbc are small, they are quite well publicised and have been going several years now, so should be getting it right.

The instructions are well produced but still require you to be a relatively good diy’er or have so experience. They also need you to be pretty well versed on bikes. Things like shimming for the disc brake isnt mentioned in the manual – infact disc brakes aren’t In there at all. It does feel a little like bbbc concentrate on there workshop weekends rather than the kit.

I bought a seat clamp, 28.6 as listed on the bbbc website. But according my calipers I need a 30mm. Something I learnt from the first kit is that I’ll expect to spend some cash on stuff that’s not quite right.

I think I’ve spent around 200 in addition to the kit on carbon fibre, glue, tools etc

Agree you’d need to be pretty well versed before makng  the jump into something like this…. but I do think anyone reading this, even vvery mechanically competent folks, would think bbbc come across as a bit of a shambles/ Every post seems to be you patiently dealing with yet another issue they’ve caused. Am sure it will put a lot pf people off.

Anyhow good luck, I’ll certainly keep reading

Quickly took a photo before work.

Bonded in the Ali to the seat tube last night, theres a little nugget of epoxy over spill internally which I’ll need to remove. Also started to sand the bb/downtube junction, it’s not quite there yet – I need to form it around the seattube, which I’ll prob bond in place this week.

An hour or so of sanding and measuring tonight…..

Headtube junction

There’s some pretty big gaps here and there, but that should be fine as they’ll get filled later. Bamboo doesn’t need to be 100% adjacent to the next tube as it’s not like welding/brazing where your directly joining the materials. The carbon fiber (or hemp) acts as a the bridge between the two.

Not been able to touch this for a few weeks, but I managed an hour or two this afternoon .

Top tube is now shaped, prepped and ready for bonding in place. The seattube now has the bottle bosses bonded in and the carbon tow is prepped ready to reinforce the area around them. I’ve decided to bond up the front triangle first and the make a 2nd vertical jig for the chainstay alignment.

I’ve also got hold of a set of Lauf grit forks, for the final build ! So it’ll be super niche.

Carbon has met carbon and epoxy, let the mummification begin.

In this case, some carbon tow reinforcements around the bottle cage bosses…..

Great thread.

Coming along nicely mate!

Bog reveal time… .

The one on the right was my 1st go and is much cleaner as my hands were less sticky giving more control on the fibers. Little bit of clean up required on the left one – but I’ve done that since taking the photo (surprisingly easy with a sharp blade).

And, the ugly side…..

Due to the way I wrapped the fibers around the bosses there was always going to be some voids on this side. Black milliput will sort it – I could cover the area with carbon weave but I’ll leave that decision toward the end of the project.

Seatpost is being bonded into possition tonight.

Quick update – front triangle is together and bonded in place, i’ll get some photos up later from my phone.

I’ve used the 5min epoxy that came with the kit, along with a standard Milliput for areas where there are voids that could be considered ‘structural’. I did look at buying some specific light weight structural filler especially formulated for carbon fibre, but it was £40 for a ‘trial pot’ and £100 for a litre.

For areas where filling voids that are nonstructural and getting shape to the carbon joints I’ve used a Milliput / Micro-Balloon epoxy resin filler mix. The micro balloons are like a fine powder used with epoxy for creating a lightweight filler – a 200ml jar is ridiculous light (50g). This combo was about 15 quid and weighs about the same as the proper stuff. i Just kneed in the micro balloons with the Milliput and it seems to work well. I’ve also some light weight model making filler (deluxe materials model lite) used for model aircraft, which is easy to sand to get a smooth finish around the joints. But i need to try this with the epoxy first as it could react, it shouldn’t but its best to test.

I’ve done the non-drive side in the jig, i should be able to take the frame out of the jig and flip it for the drive side tomorrow night. This should provide a solid enough base to complete all of the head tube and top tube/seat tube wraps out of the jig completely in a bike stand for 360degree access. The BB junction really needs the chain stays in place so ill prob add some kevlar/carbon sheet to this area only for now.