Could you not have epoxied the tubes in place in the jig, then removed from the jig for the wrap? Then you could have had 360 degree access for that part.
that's flipping awesome 😀
cannot wait to see it fully built.
Good work OP. Love this type of threads.
Could you not have epoxied the tubes in place in the jig, then removed from the jig for the wrap? Then you could have had 360 degree access for that part.
Yes.... but the chances of it moving one of the joints would have been high as you need to wrap as tight as possible.
The pros like calfee and bamboo bicycle club or Web works all seem to have vertical jigs which are accessible from both sides. For a one time use jig that came in the kit it's fine, but wrapping the frame when horizontal has its limitations.
When I've spent a couple hundred on a kit I didn't really want to spend a few hundred more on making a decent vertical jig.
It shouldn't impead the strength of the frame, just means I have more work to finish it off.
Nice 🙂
Well I can see where the 60 hrs of finishing comes from.... This is about 30mins work of sanding and filing by hand...
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Lot of work but it should look good when it's done.
Brilliant .
Certainly won't build into a light weight frame - in its unfinished form it's almost 7lbs!
Well..... its getting there...
Drive side BB joint with the bulk of the sanding done:
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Vs non drive side (unsanded)
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Mumified bike 🙂
I [u]so[/u] could not be arsed with this - you have the patience of a saint!
Did you used to paint all of your Airfix models on the spru before assembling?
Oh and White Industries make a 130mm CX Disk hub. I used to have one.
It's not all hand finished, I did the seat tube junction by hand for a bit to see how hard it is - but I've been using the dremel and finger belt sander since. To do the drive side BB as above was about 30mins with these (just not had the time to put into the project over the last week).
As for hubs, it'll be a budget built and Novatech do a 130mm disc hub. It'll be interesting getting disc alignment right. I expect either shimming or shaving of the disc adapter.
Did it come with the disc drop out? Its not clear on the website unless I've missed it?
[b]mtbtomo[/b] - It's the standard 'XC' kit which comes with disc dropouts. And is essentially a cyclocross kit - you could also do conventional rim brakes with a bit of missing. There are other kits avaliable on the wen site as Etsy, Inc a MTB kit, but they don't ship to the uk only the US.
I'll try to get some more photos up later. However if I was doing it again I'd use half the rope that they supply on a 1st cure and also wrap it with perforated electrical tape. And the either get some hemp cloth or tow for a second cure. It's really hard to get a good tight joint with the rope as it's so large. This means i have loads of finishing to do and I'll still need to sort out some pretty bit dips and holes on the none drive side - then a second load of sanding. Smaller rope / string will get a much cleaner join early on. Also the instructions recommend doing all the joints in one hit, mixing up over a ltr of epoxy for this. This means I had to rush through the joints to get them wrapped up and secure be for the epoxy started to set. If I build another I'd experiment more with a bit of fiberglass first maybe.
Also thinking I may add dried coffee granules along with my orriginal bamboo sawdust to my filler mix to bulk it out! Mainly because I don't want to use any of the sawdust I'm making as it has epoxy already in it, but also because it'll give it a darker look.
Here's some pics of where I am now.
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You can see how uneven the wrap was on the none drive side of the headtube. This will need another wrap of hemp to keep the strength. Which means I'm having to sand evtra channels into the drive side to maintain the new fibre lengths around the headtube.
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That pic needs posting in the "Aargh! My eye!" thread.
Here's what the BB joint looks like at the mo...
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The BB is in just to help keep the threads clean
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And here's the non drive side now...
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You can really see how the large hemp rope causes big areas of epoxy to form which won't give the best strength.
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I guess if you sand that too far down you'll loose the strength.. So how do you know when to stop sanding?
Clearly you'll end up with a bumpy finish at best rather than smooth.. ?
how do you know when to stop sanding?
Guess work - but if I go too far i'll be doing a second wrap with smaller hemp string in those areas anyway so the joint will be strengthened back up.
Most home built bamboo bikes use either carbon tow or hemp fibre tow. I'd like to experiment with different joints if I were doing another build. The reletivltly thick hemp and cotton mix supplied with the kit is ok, but dosent give the best or easiest finish.
Clearly you'll end up with a bumpy finish at best
Pictures don't do it justice - I'm only 1/2 way through and they should end up like this but with a more structured/stripy look:
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Ah ha, then thats pretty cool I have to say.
I'm still intrigued buy the strength around the joints, but it's looking good have to say.
You've got a LOT of sanding to do, judging by that pic. Can#t say I'd want one, but I'm interested to see how it goes.
You've got a LOT of sanding to do, judging by that pic.
That's where one of these comes in handy 😉
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[/img][TBH to get the BB area to that point has taken less than an hour with 40 grit (and I've gone through about 5 belts) - considering how out of place the rope was its not that bad. I must had had to sand it back by around 10mm or so in the BB area.
Also just had this turn up in the post:
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Since your first post I have been getting all bamboo geeky, not sure I want to buy the same kit you have now, I am fancying sourcing stuff for myself, either 'Tonkin' or 'Moso' bamboo, joints smoothed off with fibreglass, with some strategically placed UD carbon tape wrapped over with carbon tow, and compress it all using heat shrink tape (no vac bagging kit).
I might look at cheating a bit and using prefabed carbon for the seat and head tubes...
There are some more eco-friendly epoxies available now too...
Biggest issue though will be making a jig first...
I was going to go down the full on carbon route - but this is a relatively cheap and easy way of 'giving it a go' first.
If you go straight into buying carbon tubes etc it could be one expensive F up.
Here's quite a good pic of the dropouts - the chain stay drop out has had about 10mins work with the sander and 40 grit belt - seat stay is untouched.
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Love this. Keep up the good work!
Looking good mate that chain stay has cleaned up beautifully.
Starting to look a little more 'frame like' - just cleaning it up today before s second wrap of hemp and a fill of the holes and low spots (more epoxy).
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I stuck the gear cable in to work out my cable routing and if ill need any additional guides. I think I'll end up with a crossover over the top of the down tube and use the bottle cage bolts (yet to be fitted).
This is seriously impressive, cant wait to see the finished article built up!
That's starting to look really good.
Can't wait to see it when it's finished.
Suppose it's one of those things you can just keep going and going with the finish and need to know when to stop. 🙂
There's a fair bit to go yet - I could just build it up now and ride it I guess but id like to get it as nice as I can first.
I need to get hold of a 130mm disc rear wheel next just to check the alignment is ok on the back end - if it's out, i'd rather take the rear end apart now than after more work. I will try to get the headtube area rewrapped with 1mm hemp twine in the low spots this week - I've sanded back additional material on the drive side to accommodate the extra material I'm just waiting on the hemp to turn up in the post. I'll also try to compress the second wrap with electrical tape to try to get as smooth and tight a finning as possible (less sanding and a stronger joint).
If/when I build another i'll use my own joint material, as I said in earlier posts the stuff in the kit is ok, but If your sanding it back it's way too thick.
This looks amazing, I would love to give it ago but my wife doesn't trust me.....
Will watch this to see how you get on, really looking forward to the results.
Cheers, Steve
Just bought a set of [url= http://www.planetx.co.uk/i/q/HUVIME40/vision-metron-40-road-disc-rear-28-hole-hub ]these[/url] Vision hubs for a bargain price in the Planet X sale - just need to fined some suitable rims.
Tried out a coffee / epoxy filler mix today but completely forgot to take photos. Also tried an electrical tape wrap. I'll unwrap it in thd morning and try to remember to take photos....
Here's a couple of pics of the coffee/epoxy mix after I unwrapped it this morning.
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It sands back nicely so I think I'll carry on with this method for filling the gaps before any 2nd wrap of hemp.
Nice!
[url=
Conway is currently riding a bamboo bike[/url] on the bike leg of his UK coast triathlon and [url=
friend built himself one earlier this year[/url].
Hub arrived today..... and it's 135 OLD ! TYPICAL. So I'm sending it back - may have to go with so nova techs.
Also I've worked out why the stays didn't fit the non drive side dropouts - some how I did manage to put the wrong stays on the wrong side. If you look at the photo below you can see how the longer seatstay should have extended below the disc mounts. I may strengthen the area by sliding some bar up the seat stay and bonding it in. But i'll probably just see how it rides first - assuming it's straight (off to the lbs tomorrow to see if they have any old 700c rear wheels).
On the plus side my coffee filler mix is coming up nicely after a bit of sanding back, it'll endup looking a bit like a brown camouflage joints at a guess. I'm hoping to get another hemp wrap of the head tube done tonight, and possibly the seat tube junction. Then it'll just need the fine sanding at the weekend.
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Bb joint is almost done and is looking pretty good but i cant take any phot is at the momen as i didn't get around to doing the 2nd wrap earlier in the week so the frame is screwed to the worktop and covered in electrical tape. The 2nd wrap (hopefully) is this afternoons and tomorrow's job.
Here a pic of the headtube wrapped up. I did the wrap at about 3pm yesterday, usually epoxy should have a good cure after 12 hrs, checked this am an my test pot is still a little soft and tacky, so i'll leave it at least another 12hrs until i unwrap it and can do the seat tube junction. The
Epoxy im using should be at around 20°+ when used, and I'm doing it in my garage which isn't heated + I'm using it quite thick so it needs the extra time.
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Its coming together well, and looking good too.
I have (yet) another question, do you know what sort of bamboo they supplied and has it been treated at all? Lots of sites I look at are on about drying and going over the poles with a blowtorch to do something to the natural resins in the bamboo, others talk about using boron salts or similar to drive out bugs, reduce water absorption and prevent mould later on...
Anything like that come up when you bought your kit OP?
[b]Cookeaa[/b] - afraid not. There's no info on the bamboo species or how its been dried out. Personally I'd stay away from buying green bamboo and drying the bamboo your self - from what I've read if you use the blowtorch method it fast dries it - stem coming out the end of the poles! And may make the poles brittle and more likely to split or cracks to form at a later date (once the frame is finished).
If your going to go down the specific species etc. Your best off speaking too or visiting these guys https://thebamboocompany.co.uk/ they are the UK bamboo importer and should be able to talk through the properties of each plant and drying process.
I'm only using this frame as a first build - already learnt a load of stuff. I'd like to go down the complete custom (rather than a kit built) frame for the next one.
Just got back bespoked - only one bamboo frame I could find this year.
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I'll leave the frame for a couple of days I think, as it's way too takey to work on and I want to do one joint at a time.
But I just sprayed so ipa over the bb junction to clean it up. It shown what the finished area should look like after an epoxy glaze.....
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