Lyrebird Cycles

[Mark Kelly]

I have previously covered DIY prepreg using high TG epoxy and woven carbon. Until now unidirectional prepreg has been a problem but I've worked out a way of making my own, which means I can use the higher spec tow I use for filament winding. I am using Toray T1000 here which is 300 GPa vs about 240 for the commercial prepreg.

I set up the filament winder with a drum of appropriate diameter covered in non-stick paper:



and set it to hoop winding with an appropriate feed rate (2 mm for the 12k tow):



(sorry for the shit pic, camera autofocussed on the winder not the drum).

Whe finished I simply slice the non stick paper and cure in the oven to beta stage et voila, unidirectional prepreg:

[Mark Kelly]

Hi Mark,

Can you tell us more about the carbon dropouts in FNL?

It's been a lot more than a week but here they are:


Polydrops

Sorry but the combination of black dropouts on black carbon and my shit photography aren't going to light the world on fire.

They worked out well but the next frame will use Paragon's "Bolt On Brake Interface" which should be easier to adapt, I am hoping it work at least as well.


K_Bike_Scales

On the other hand, I believe this is the lightest wood frame yet made by some margin at 1056 g. My wife says I should have made it ten grams heavier.

I'd post a pic but I forgot to take any of the frame.

[Colinmclelland]

It's been a lot more than a week but here they are:


K_Bike_Scales

On the other hand, I believe this is the lightest wood frame yet made by some margin at 1056 g. My wife says I should have made it ten grams heavier.

It must be child sized though

Like the BB evolution...took me a while but I finally got the 10g thing!

[Mark Kelly]

Small to medium, to fit a 165 cm rider.

Re the BB thing: thanks, this is my first attempt at something I am very hopeful for. It's an adaptation of yosegi zaiku, a traditional Japanese inlay technique. Each of the little bands is a separate strip of wood ~1mm wide, the thicker bands are simply two strips, so there are 30 to 40 individual pieces in each tile. The advantage is it's much more adaptable than the single wooden tiles I previously used. It looks a little busy close up but from further away it's actually quite subtle.

I will eventually post up a little description of how it's done. I found the existing information a little frustrating as it is all hands on: do this and this and this and you'll get this result, while I wanted to know how to calculate the shapes and angles from first principles. To that end I worked out the trigonometry that governs the technique so it's all good now.

After doing this bike I realised that I've been doing the joints backwards all along, I am going to try defining the joint area to have a constant width inlay band then adapting the tube laminae to fit that. I will also drop the carbon webs, they are too much of a PITA to do and I've never got them to work quite as well as I wanted.

[Colinmclelland]

Thanks Mark. The old yosegi zaiku.

...snip... I will also drop the carbon webs, they are too much of a PITA to do and I've never got them to work quite as well as I wanted.

Just for kicks, let's pretend I'm not sure what you are talking about here....

[Mark Kelly]

Lovely article on the resilience of Lyrebirds in the face of the devastation wreaked by last summer's fires, published today.

Besides being an interesting piece in its own right, Lyrebirds surviving bushfires is a bit of a theme for me.

[RichTheRoadie]

Seems appropriate to share this here too:

[Mark Kelly]

Wow. Thanks Rich.

[Colinmclelland]

That's the sort of thing you could be "blowing up" Matt's Instagram feed with....

[Mark Kelly]

For those who want to know what I look like when I haven't had a decent night's sleep for a month:




"Meet the Maker" courtesy CyclingTips

[Ras72]

Three hundred hours. Three HUNDRED hours. THREE HUNDRED HOURS.

Thanks for sharing that Mark! Masterful, beautiful work!

[Mark Kelly]

I did't like the yosegi zeiku inlay on the frame above so I've changed it. I like the simplicity of the new version, what say you?




Sorry for the lousy pics, I've never been a good photographer.

[RichTheRoadie]

I did't like the yosegi zeiku inlay on the frame above so I've changed it. I like the simplicity of the new version, what say you?

Your best yet, Mark.

I liked the previous iteration, but this gives a modern edge to your bikes; and the ‘arrow’ at the join gives a sense of forward motion. Love it.

[woodworker]

Really stunning work. Beautiful.

[Mark Kelly]

Thanks Guys.

Rich, I agree regarding cleaner lines, it made a greater difference than I expected. Future iterations should be a little neater; retrofitting to the existing layout was a pain.

[Colinmclelland]

I did't like the yosegi zeiku inlay on the frame above so I've changed it. I like the simplicity of the new version, what say you?

Wow. I’m a fan. Late, but a fan. That is a cracker.

[Mark Kelly]

Thanks Colin.

Speaking of late, the new website is up. Still at beta stage as we work a few things out: the text in particular needs reworking.

[RichTheRoadie]

Site looks good, Mark!

[Colinmclelland]

Site looks good, Mark!

It does indeed. Only looked on my phone, but I’m intrigued enough to fire up a laptop.

Rich will probably buy one to flip, but I don’t think I can swing any of the $10k jerseys. Based on the price of socks, it’s probably not long until that’s seen as reasonable though!

[Tristan]

Thanks Colin.

Speaking of late, the new website is up. Still at beta stage as we work a few things out: the text in particular needs reworking.

Looking good Mark, but YOU are the selling point for a frame, not the tech or the process. It needs a LOT more about you - your approach, your ideas, your background, your personality. Some photos of your toiling over the filament winder you built, sipping a glass of vino etc etc