Self Build Bamboo Bike Frame Kit Build Thread

[chriswoody]

Thanks everyone, sorry for the pause in proceedings. I work as a teacher and January is a crazy busy month for me. I teach the best part of a hundred pupils and in the last weeks I've had to mark end of semester assessments and write reports for each of the little darlings. I'm mostly done, but still a little way to go. With two young kids of my own as well, life's a little busy this month and no real time for working on Bamboo bikes.

Fear not though normal service will be resumed soon. In the meantime I had stripped the protective paper off just to check all was well underneath ad then I really couldn't resist mocking the bike up for a look:

So thanks again all for the interest and normal service will resume soon.

 

[chriswoody]

So I've finally managed to get some of my life back and found time to work on the bike.

The lugs have set nicely and I've been sanding all of the high spots with a mix of sandpaper. Whilst making the lugs it's really critical to compress the joints while they set, with electrical tape. However, this has left me with a lot of valleys and ridges in the finished lugs. It's important I don't sand to deep, so it's a case of just trying to make things smooth, but not flat.

The final result looks quite rough, but it is smooth. According to the instructions, a new coat of resin will restore the finish, so I'll be giving that a try. Being as I'll be making up a small batch of resin, I decided to also make up the cable stops and use the resin to glue them to the frame.

The kit has a large section of Bamboo for creating the cable stops.

The first job is to drill a 3mm hole right through for the cable. I followed this with a 6mm hole about 8mm deep for the cable end cap to sit in.

Then I separated the stop from the rest of the Bamboo, trimmed and shaped it with a Stanley knife. Sorry the photo of the finished stop is a little out of focus, but it's a little tricky to photograph such a small thing!

So a little bit more prep work, then I'll make up a new batch of resin and see how it all looks.

 

[Smokin Joe]

I've been looking forward to an update, Chris. Good that you're taking your time and not getting impatient to finish the job.

 

[adamhearn]

However, this has left me with a lot of valleys and ridges in the finished lugs. It's important I don't sand to deep, so it's a case of just trying to make things smooth, but not flat.

If you're concerned about the level of flatness, could you not use some more resin as a filler?

As Smokin Joe said, great to see an update!

 

[chriswoody]

The problem I have at the moment is one of prevarication! I'd originally planned to use filler and smooth the lugs out, then paint them a nice colour. However, I saw a picture of another home built bike, in which they'd Lacquered everything and left the hemp it's natural colour. It brought to mind an old wooden sailing dinghy and looked lovely.

So I've been a little curious about wether I could produce a nice finish on these lugs, and keep them a natural colour. As you rightly say, I was going to experiment with using the resin to flatten out some of the valleys and see where we go from there. If it doesn't work out, then it still makes an excellent base for the filler and paint approach.

Another thought though that I really need to pay attention to, is that this is a homemade bike and I'm no expert. So I need to be happy and embrace any imperfections. After all, I want to retain some element of it's hand-built origins and not slave away for hours trying to recreate a factory finish and only be disappointed when I can't do it.

Lastly I also weighed the frame last night out of curiosity, it was 2.4 kg, without forks. The forks I have are steel and weigh 900grams, I could have bought some Carbon forks that weigh half that, but I love steel more. So all in, sans headset, I'm looking at 3.3kg. I also weighed a Reynolds 501 frame I have and that weighed 3.9kg with forks and headset. So I don't know how the Bamboo frame compares to a high quality 531 or equivalent frame set, but I thought it generally compares quite favourably to steel in weight terms.

 

[chriswoody]

About time for an update I think. So I've been busy sanding the lugs and trimming away excess resin. There's a wonderful saying about experience being the one thing you gain right after you needed it and that certainly holds true here. Whilst I was making the lugs, I was no where as neat and tidy as I would have liked and I would have really benefited from using wider electrical tape for the compression. None of this has affected the strength of the joints, but it's resulted in work that's not as neat as I was striving for. However, it's no great issue, just a little more work sanding them back and my minds made up that I'll paint the lugs.

I also decided to revisit the cable stops that I'd made. Looking at other Bamboo builds I realised that my cable stops were a little chunky and ugly. So I sat down with my whittling knife and some sandpaper and trimmed them down to a much more svelte profile. Quite a satisfying hours work.

With the stops finished and the resin smoothed it was time to recover the frame and mix up some more resin and apply it.

So the cable stops are now epoxied to the frame and super strong and the lugs have a fresh coat of resin.

The next step will be a dry build of the entire transmission. Being as I'm building a single speed, I want to check that the chain line is nice and straight and that the Bottom Bracket fits. I would dry build the entire bike, but I don't want to install the headset until the head tube is painted.

Once the part dry build is finished, then it will be onto the final finish and painting of the lugs.

 

[Elysian_Roads]

About time for an update I think. So I've been busy sanding the lugs and trimming away excess resin. There's a wonderful saying about experience being the one thing you gain right after you needed it and that certainly holds true here. Whilst I was making the lugs, I was no where as neat and tidy as I would have liked and I would have really benefited from using wider electrical tape for the compression. None of this has affected the strength of the joints, but it's resulted in work that's not as neat as I was striving for. However, it's no great issue, just a little more work sanding them back and my minds made up that I'll paint the lugs.

I also decided to revisit the cable stops that I'd made. Looking at other Bamboo builds I realised that my cable stops were a little chunky and ugly. So I sat down with my whittling knife and some sandpaper and trimmed them down to a much more svelte profile. Quite a satisfying hours work.

View attachment 395561

With the stops finished and the resin smoothed it was time to recover the frame and mix up some more resin and apply it.

View attachment 395562

So the cable stops are now epoxied to the frame and super strong and the lugs have a fresh coat of resin.

View attachment 395563

View attachment 395564

The next step will be a dry build of the entire transmission. Being as I'm building a single speed, I want to check that the chain line is nice and straight and that the Bottom Bracket fits. I would dry build the entire bike, but I don't want to install the headset until the head tube is painted.

Once the part dry build is finished, then it will be onto the final finish and painting of the lugs.

Great thread, @chriswoody. A good old fashioned serial programme rather than a box set weekend binge, though will confess to going back to the beginning and having a recap. Curiously, a bamboo bike appeared on the "maybe of interest?" thread you get on eBay. Turns out there are a few on there including a btwin based one, and a couple from Ghana, though not sure if they come from the initiative that @Cycleops referred to previously.

 

[AndyRM]

I've just caught up on this thread. Amazing work @chriswoody, much respect for your workmanship and patience!

 

[chriswoody]

Thanks for kind words, it's good to see people are enjoying this as much as me!

As a few of you have commented, I am generally taking my time and being patient, however there are times when this doesn't hold true. One of them being earlier this week. I really shouldn't have been near tools of any sort, I was tired and suffering from the start of a blinding headache. Still, I ploughed on and was doing O.K. until I reached the installation of the right hand Bottom Bracket cup, the same one that had given me grief earlier in the build. Remembering that it was still a little tight, I carried on trying to force the cup in, way past the point I should have stopped. Luckily, I did finally stop myself before I had wrought to much damage, but I'd still managed to cross thread the first few threads. Cursing myself for my stupidity I finally stepped back from the tools and left it for a couple of days.

So the only remedy was to take it down to the bike shop. At the first one I tried, the guy looked into the wrong half of the shell and upon seeing some old copper slip in the threads, proclaimed he could see the problem. When I pointed out his mistake, he sheepishly said that he doesn't have a thread reaming tool. So off I trotted to the shop down the road. The first chap I spoke to enthusiastically proclaimed that it would be no problem, grabbed the frame and trotted of to the workshop. He then proceeded to grab half of a Bottom Bracket tapping tool and tried to use it freehand and skewed on the threads. I was about to tell him that that wasn't how you used that tool, when I young lad appeared, grabbed the frame and the rest of the tool and thankfully decided to do a professional job. In fact, he did such a good job, that the threads are now pretty much immaculate and the BB screws in really easily.

So with all those dramas out of the way, the rest of the transmission went together with no dramas and it was great to see the bike come together at last. So great in fact, that I dragged it out of the dark cellar and into the sunlight for the first time.

The dry build has thrown up a few issues as I thought it would. The bottom of the Seat Stay actually rubs against the chain.

This has had the effect of deflecting the chain and also interfered with the chain line, however, it does still look pretty straight, which I was pleasantly surprised at.

Given I'm using a Hollowtech Chainset, (Because I had it lying around spare and I'm trying to keep some costs down) I don't have the flexibility to change the axle length that a square taper would give me. I think this is going to be acceptable though.

So A little bit of sanding and fettling ahead, but nothing too drastic, then preparing the lugs for paint.

 

[themosquitoking]

What colour are you going to paint it?​

 

[chriswoody]

Colour is the million dollar question. The bike that inspired this madness, was a lovely electric blue, with silver wheels, stem etc. I really wanted to go down that route, however, as I started sourcing various bits it became apparent that silver was a hard colour to come by for some of my preferred components. So I ended up with black wheels, stem, chainset etc.

I was still really keen on the blue though. Recently though my family have all been pushing for green. I've never been totally sold on the idea until i saw a bike in green which was close to British racing green and an all black groupset, wheels etc. So now I'm torn and I'll probably try a bit of both on some old scrap and see which I prefer. Ultimately though it is only the lugs which will be painted and when there finished the whole frame including the raw Bamboo will be lacquered. So it's trying to find a colour that will also complement the raw Bamboo colour.

Paints wise, I was going to go down the car paint route, which is going to be a lot of effort to get a reasonable finish. But then I came across spray.bike who produce an interesting spray paint for bikes. It basically acts like a cross with traditional powder coat and spray paint, it goes on matt and needs a few coats of lacquer to create a gloss finish. Their instagram page has some interesting examples of finished frames. It seems to produce some good results with much less effort than car paints. So again i'm going to order some and experiment. Who knows how it will all go, but thats why this project is so much fun.

 

[Smokin Joe]

My hat off to you, what a fantastic project. Sure beats an Airfix kit.

 

[chriswoody]

OK, so progress has slowed a little, I know, I know, I was already moving along like a tortoise! The hold up now is the weather ironically. Up till now I've been working in the relative warmth of my cellar, however, I now need to smooth out the lugs prior to painting and this requires the use of filler and sanding. The filler gives off terrible chemical fumes and the sanding, well, to say it makes a mess would be an understatement, so outside it is.

I started by stripping the bike back down and sanding and trimming the areas that where fouling the back wheel and chain. With that done, it was on to the first batch of filler.

Then when it had set it was time for the dust to fly:

Some areas need more filler than others, but it's slowly coming together. I've applied two coats so far, but there are still small voids and gaps, so I'll need to apply some more. But that needs to wait until the weather has returned above freezing.

 

[alicat]

Good job with the filler.

 

[Randy Butternubs]

I've lost track of the aesthetic decisions. Are you painting some, all or none of it? Are you going to paint over the smoothed lugs or do a final neat wrap with the cloth & epoxy?