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How did you attached the dropouts to the chain stays? Did you just glued in some aluminium pipes? Why not screws?

Yes. 10mm dia aluminium tubes just glued in a fairly tight fit hole. I just prefer how they look. The screws on the seat stays were unavoidable because they are threaded into the dropouts. This is beacuse space is tighter at the top due to chain clearance

Frame weight is bang on 2.2kg, which is disappointing. Thought I was going to be able to get under 2kg. Haven't done an all up weigh in as it's not all built up yet.

Speaking of which, there's no headset in the photo above. Not sure I have the patience to make wooden spacers now. Just want to get riding! Cool idea though.

And the moment we've all been wating for. Only first fit up because, stupidly, I hadn't realised that the donor bike that I have has 1" forks. They also look a bit spindly as they were on a steel frame. Ordered some chunkier forks to go with the enourmous down tube.

Also still needs Ligneus logo and bottle cages.

Frame done.

Its difficult to get the colour and grain to come out properly in the photos. Here's a shot with and without flash to show what the light brings out. Needs a bright sunny day to get the best out of it.... so maybe I'll get a decent photo next summer!

Err... no.... only joking. I was expecting more of a reaction though. Maybe it was that obvious.

Unfortunately I'm limited by the terrible light in my spare room and photos on a camera phone. After 6 months I'm afraid you'll have to wait a few more days for decent pics when I can get it out in the sun after a few more coats

Got a pair of these to go on it

Nearly there. A couple more coats of varnish to go. It changed colour dramatically when I put the first sealer coat of epoxy on so the red components that I've got for it aren't going to work so well now. I've included a before and after pic to show the difference. I've also never shown a pic of the drop outs so here they are ready to go.

Big thanks to Matt at Talbot frameworks for help with the reaming (think I managed to avoid the innuendo there). Very helpful and knowledgeable chap. I also got to see his clever integrated di2 frame from Bespoked with the electric cables painted onto the frame in silver filings.

Final sanding and varnishing still to go before its finally complete.

Amazing. PM sent. Cheers Nick

Once again, painfully slow progress so no new pictures but it's getting pretty close. All glued up drop outs made, mech hangers aligned and fitted and final sanding in process. Almost ready for varnishing. But, before I do....

does anyone have a head tube and seat tube reamer and facer that I could pop over and use in return for beer/ wine or recommend somewhere (cheap) that will do it for me?

Might be ready for the planned finish date in June for the big rides this season..... oh, wait.....bugger.

Cheers
Nick

The single speed frame is at least as stiff as the steel Condor frame but is more comfortable as it absorbs vibrations better. It's not as stiff as large tubed alu or carbon frames though. Most of the flexibility that I've noticed comes from the lateral stiffness of the rear stays. I'm going to see how the stays on this frame feel when all glued up and may need to add an extra lamination to the inside to stiffen them up if need be.

So the conclusion is that I'm quite happy with the robustness of the tubes compared with an off the shelf alu tube and the actual frame is thicker than my test sample (I got chicken) so will be stronger.

To put the test numbers into perspective, the wooden tube failed at around 110kg with a point load of around 1sqcm. I tried jumping on it (80kg) with my heel and hurt my heel but not the tube.

QED

Here's the wooden tube and a section of alu seat tube after being taken to failure

You can hardly see a mark on the wood but the alu tube is clearly dented.

Now for the interesting bit. What were the results? I did quite a few tests but have distilled the results into this graph

The sharp eyed will spot that the curves should be linear at the start (before the samples have yielded) I think the odd shape os probably due to my highly non technical test rig and some 'bedding in' movement that happened in all the tests (the foot pad is slightly spongy!)

The alu tube failed at a much higher force than the wooden tube, which dissappointed me as i was expecting it to perform better. I've also plotted the 'reload' curve after I reloaded the wooded tube several more times. It performed reasuringly (suprisingly) similarly under smaller loads despite having clearly failed in the first test.

However, I spotted something quite promising. What if we're not interested in the size of the impact force, but rather the energy of the impact. This would be equivalent to dropping something on the frame, or dropping the frame on something and absorbing the impact without damaging the frame. The energy absorbed by the tube is the area under the curve, which, is considerably larger for the wooden tube.

So, despite failing at a lower load, the wooden tube can actually withstand a larger impact because it is more flexible and deforms more enabling it to absorb more energy.

What this does not show is the post yield energy absorption as the alu tube would have a much better post yield behaviour.

I'd love to do the same for a carbon tube to see how it compares.

Anyone got a write off frame that I can cut up and test?

I haven't really unleashed the geek on you guys yet so far this build so here's some info on some background studies that I've been doing on the side.

The main difference between this build and the last wooden frame is the thickness of the tubes, all in the name of reducing frame weight. However, at less than 3mm thick in places it worries me that the frame may be too fragile. I've done the calculations to convince myself that the overall frame will be strong enough and stiff enough to perform well (similar to other high performance frames) but side impacts on the tubes are harder to check and there are no standards that give any tests or requirements for impact resistance. We've done some FEA modelling (computer stress analysis) to check this, using conventional steel and aluminium tubes as benchmarks for 'impact resistance', but the orthotropic and highly non linear nature of the wood makes the analysis difficult and the results dubious.

So, i made a test sample. 2mm thick Ash with internal stiffeners

The tube was very fragile before the stiffeners were fitted but felt very robust once glued together and only slightly heavier than a Columbus Airplane alu top tube.

I set up a highly technical test rig with a G clamp and my bathroom scales #backyardengineering

Crank puller taped to the G clapm to apply the point load!

Progress has been painfully slow. Holidays, weddings, sportives, work...... but no bike building.

Here are some current pics. Internal cable guides and internal stiffeners fitted and all the inserts are ready so it's pretty much ready to be joined together and start looking like a bike frame

Very good. What does the chain loop around at the bottom, just a loose sprocket or is it connected to the wall?

Yes, just a loose sprocket. Without it the chain hangs and looks quite pointy at the bottom. The loose sprocket just spins with the chain and makes it look nicer.

Genius. How does mrs. Linc like it?

The jury's still out. Initial comments:
'It's quite big, can't you make the chain smaller'
'It looks a bit industrial'
'That better not get oil on the wall' (Fortunately I did get new chains and degrease them rather than my first thought which was to use a couple of old ones that I've got in the spares box!)
'How do you actually tell the time off it'
'Wouldn't it be easier with hands'

I'm hoping it's a grower.........

Fantastic! Instructions pls!

Ok, it's pretty simple. Not much other than what you can see. I'll write up a quick 'how to' when I've got a minute

Mrs Linc - "When are you going to stop messing around with bikes and sort out something nice to brighten up the living room?"

I'm not sure this is quite what she had in mind or that it counts as stopping messing around with bikes but I'm quite pleased with it nevertheless.

So, I present the crank clock

The numbers round the chain show the hour at the top of the chain while the black hand on the jockey wheel shows the minutes. Top sprocket rotates once per hour fixed to the hour spindle of a cheap clock mechanism.

Vintage Stronglight crankset, 12t sprockets, 12t jockey wheel, 144 link chain, set of bearings installed in the crank spindle hole and a high torque quartz clock mechanism at the back.

IKEA? Cheeky bugger!

In other news, I'm also going to make up a dummy section of tube to do a crush test on and see how the actual stiffened tube compares with my calcs. I'm not worried about the strength of the tubes along the length of the tube but I'm intrigued as to how fragile they are to lateral impact. After all 3mm of wood doesn't stand up to much as a flat sheet.

I'm not normally a bike weight wenie. In fact I pride myself on riding a 10kg home build and passing the carbon TT bikes when I'm training in the park. This build, however, has got to me. I guess it comes from starting the design with a frame weight goal and being an anal engineer!

So here goes:

First frame half complete, second half is work in progress:

So that's 1270g for both halves of the frame

500g for all 4 stays

Seat post insert 74g

Bottom bracket insert 71g

Miscillaneous inserts for bottle cages, rear brake bridge and cable guides

Internal cable housings.

So far that's 2060g. Then there's another 150g for the head tube insert, 150g for drop outs, 200g for epoxy sealing coats and varnish and say 50g for internal stiffeners.

All up weight is looking to be around 2.5kg which is a lot more than I was anticipating. In fact I think the single speed frame came in at 2.6kg and this is a hell of a lot thinner and I've removed a lot more material around the joints. However it does have bigger tubes. Hmmmmm.......not sure what I miscalculated in the first place!

Anyway, there's not much I can do now and I certainly can't make the tubes any thinner.

Oh, and it was great to see the Woodelo frames at Bespoked today. Glad my vote counted to them getting the prize for best frame builder by public vote.