Bamboo 2

[gecko76]

It's arrived.

Unfortunately I'm at the other end of the country, and won't be home until Saturday.

[fatbikephil]

Looking forward to seeing it come together - is it the one with the cast lugs?

[gecko76]

That's the one. And I've promised myself that I'm not going to be doing any drilling, sawing or carving beyond what is strictly necessary.

[gecko76]

Looking good.

Liking the engineered chainstays. This is going to be fun.

[Lazarus]

What is the weight of the completed frame ?

I am tempted by one

[gecko76]

https://bamboobicycleclub.org/products/ ... -build-kit

"The gravel frame lugs are made from recycled aluminum. They are very durable and easy to bond with the bamboo. The lugs weigh 1.2 kg, so you can expect a frame weighing between 2.2 kg and 2.5 kg."

I'll be happy with that but will let you know. I'll weigh the old one properly too before dismantling it for parts (the carbon seat tube, and the head badge).

[gecko76]

Taking it slowly, and before I go any further the shed is going to need a damn good tidy, but got the headset cups installed using the vice at maximum extension.

[Zippy]

Nice! A lot easier to do that when you've got just a small section of the frame rather than the whole thing

[gecko76]

Right, except I subsequently realised I'm going to have to adjust the jig ever so slightly to account for the cups.

Hoping to get that set up this weekend.

[gecko76]

Well, just going by the head tube cluster, it looks like the new frame will be a bit lighter than it's predecessor.


Quite satisfying cutting up the old frame for recycling/composting.

Not sure about the jig. Laser cutting is all well and good but as anyone who has built a ferris wheel or whatever on Christmas day knows, hardboard doesn't lend itself to tight tolerances. The pieces have been kept inside so shouldn't have absorbed any moisture, but some of the tabs were a very tight fit, and the dropouts in particular are going to need a bit of fettling to make sure they're in the right position.

[fatbikephil]

Definitely a very Organic way of building a frame!
I suppose you could fab up a metal jig to ensure tolerances are met but I guess that defeats the object of the exercise....
Keep at it

[gecko76]

Yeah, been thinking of ways to improve that bit of the build. Might try whittling a piece of flat aluminum to replace the two critical pieces that won't quite sit right.

Got the bamboo marked up for shaving to fit the lugs.

Doing the mitres was tricky last time so glad not to have to on this one.

[gecko76]

Haven't decided on the seat tube yet. Would like to reuse the carbon tube but it will need an insert top and bottom and the internal diameters don't quite match so, for want of a lathe, it'll be a case of what I've got in the shed,

[Charliecres]

Looks like fun! Interested to see your progress

[gecko76]

Slow progress, hoping to get it together over Christmas. In the meantime I realise I've given myself a problem by inserting the headset cups prematurely. Currently contemplating the best way to fix that, whilst cogitating over the dropouts too.

Not heard back from the company but I know he's been busy.
https://youtu.be/bqgzwbehtEY?si=JzGl7uCBAuAI_128

[gecko76]

Or y'know, could just get my finger out.

5lb on the button, which will be a bit more when glued and the dropouts and hoses/cables are installed, but not much.

[gecko76]

Update time, though not much to report apart from a very helpful chat this morning with Andy of https://armourcustombicycles.com/home

In short, he's happy for me to make use of his jig (and extensive experience) so I'll head along to his workshop early in January to get it all aligned and glued up prior to a short bake in the oven to optimise the curing of the epoxy.

Couple of points:

The design is such that he's not worried about his jig getting messy - it's not a wrap.

Putting the headset cups in early shouldn't be a problem because the bit of the jig that goes against the bottom cup is flat while the top one is conical.

The epoxy is supplied (ET4528) is 'thin-shearing' which means it'll flow nicely where it needs to go before putting the whole arrangement in the jig to fix it in place.

I'll use the qr dropouts for the build phase as they're nice and square and easier to clamp in the jig, and swap them for bolt through later.

All for a bottle of Bunnahabhain

[fatbikephil]

Good you got sorted with a friendly frame builder Gecko, eagerly awaiting the next episode!

[Lazarus]

I have also enjoyed this...am tempted by the kit but really dont need another bike and certainly not a drop bar one

[gecko76]

Dry fit

[gecko76]

And now glued - much easier to put together with the epoxy acting as a lubricant. 6 hours in front of a heater and then 40 minutes in the oven tomorrow to set it off properly.

Bit of a moment when one of the seatstays started to crack during the dry fit (the walls are very thin to fit in the lug) but a wee dab of epoxy and a blast in the oven remedied that.

Think I've got all the necessary bits to build it up but will inevitably have forgotten something. There's sanding and oiling before we get that far anyway.

[fatbikephil]

Nice work!
I can't think of any frame builders sorting a cracked tube with epoxy!

[Keith74]

That looks brilliant.

Have been tempted to get a lot myself but then I keep on looking at all the other projects I have in the shed and think better of it. Would it of been a struggle to get it all lined up without a frame jig?

[gecko76]

Don't want to say too much before hearing back from the company that supplied the kit and original jig but Yes, having a proper jig meant it was possible to wrestle the tubes into alignment and hold them there, in particular the dropouts.

[gecko76]

Right, got the frame back and the build has commenced. Andy was absolutely fantastic and a massive help.

Now, first hurdle is finding out the rear bolt through axle I bought is too short, so it'll be back to QR while I source the right one. In the meantime, it's new hoses for the brakes. Tell me what pitfalls to avoid.