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That would be awesome. I'll PM you.

I need a few frames.....anyone else?

Hi

I need some sections of tubing for my next project, not a whole bike. Does anyone have any dented/ cracked/ written off frames that they'd donate to be cut up and put to good use on a project?

Aluminium frames preferred but I'm open to suggestions if there's a steel frame on offer. Not only will I help clear space in your shed but will happily pay a small amount/ buy a pint to anyone that has anything suitable.

Cheers
Nick

So, now onto the more interesting bit..... the next project!

This has been bubbling away for a few months without any action but I'm about to start Mk2. What'll change?

Well for the past few months I've had an engineering student at Oxford University (seriously!) doing a masters thesis in optimising the stiffness/ strength to weight ratio of wooden tubes. This isn't finished yet and has a few months left to go but should be interesting putting some of the theory into action. I've also procured the use of a CNC machine so we can build it faster and to better tolerances.

Aim is to get to as close to 1.5kg as possible for the frame without compromising stiffness. I very crudely tested the stiffness of my current frame against a friends Cervelo S3 and the wooden frame is undoubtably stiffer. It does weigh twice as much though. But that tells me that I could do exactly the same again, thin the tubes to reduce the weight and it would still be stiff enough. And that's before we've applied any of the research that we've done.

Watch this space................

Haha. No photo's I'm afraid apart from the one's that I already posted previously http://ligneusbikes.wordpress.com/hardwood-single-speed/photos/
I've probably got 1500 odd miles under the wheels now. I ride it as my only bike now for commuting and weekend rides. The plan is to get as many miles done as possible to see what goes first. Been through a set of brakes and a set of tyres but the frame is holding up fine. Has also been out in rain, snow... the lot over the winter and hasn't had any issues. Even came off on some black ice on a roundabout the other week but fortunately the saddle took the brunt of the impact and the frame was untouched..... my knee on the other hand. The varnish has had a couple of scratches from the bike shed at work but nothing that some sand paper a brush and the pot of varnish can't fix in 5 mins. In fact the gloss finish cleans reallly easily and doesn't hold oil at all.

I've certainly met a lot more people out on the roads since I started riding it. Literally every day someone will ride up and have a chat on my way into work.

Does anyone have a spare ticket that they aren't going to use any more? I really want to go but it is sold out now. I can pick up and pay cash tomorrow.
Cheers
Nick

Lovely frame. I'd be seriously careful about using a front brake on that though. The clearance to the down tube is so tight that it looks like a faceplant waiting to happen with a front brake.

Poor quality phone photo taken during a pi$$ break on lap 2 of Box Hill for our Olympic Road race course ride (only 2 laps of Box Hill though). I was going to make a comment about the bike being back in its natural environment but it would probably have to be in some Brasilian rainforest for that.

I've glued in some threaded inserts so I can now carry 2 water bottles for the long rides. It was very comfortable for a 100+ mile ride and I was only beaten up Box Hill by a friend on a 7kg Canyon full carbon weight weenie. I did weigh it the other day and it comes in at 10kg on the dot. I guess with better components that could easily be reduced by well over a kilo but I've never been massively bothered by weight weenie nonsence. Better legs are all that's needed.

I wonder if a similar situation is happening as you get out of the saddle .. ie the wood is absorbing the pedal force and then releasing it more gently then the undamped Pista frame?

That's a really good point. It would explain why it just doesn't feel as lively. Almost worth the sacrifice for the buttery smooth ride in the saddle though. Another thing i've noticed on the same subject is that if you pick up the bike and drop it, it hardly bounces at all and doesn't clatter around like a normal frame would. A bit like one of those magic drawers that you get in fancy kitchens that you cant slam!

.. the other way I see it is wood is a composite product so in theory you should be able to improve this by specific grain alignment .. easier said then done though I think?

All the tubes have the grain aligned along the length of the tube with the grain crossed over at the joints for joint strength. The one thing this isn't very good for is the twisting forces (torsion) that you get in the down tube, especially when you get out of the saddle. Wood is well known (but poorly documented) for being awful at carrying these twisting forces and my original design was a guess at best when working out how much effect this would have on a bike frame.

A much stiffer frame could be made in a similar way to carbon fibre by wrapping a tube with thin wood laminates at +/-45 degrees to each other so they spiral round the tube but it would make jointing much harder and it mght look more like a chinese wicker basket than a bike! Please don't get me thinking about the next one already! I've got a lot of making up time with the other half (+ riding the finished bike) before I'll be allowed another project : )

I forgot, I've got a question for you lot. I've got Sugino cranks, Stronglight chainring and a freewheel on the back. Sheldon told me that I needed a 109 bottom bracket so I used a 110 Shimano BB that I already had. It sends the chain line a mile off and I've had to mount the chainring to the inside of the cranks to get it to run straight. I'm measuring 42mm from the center of the rear hub to the centre of the freewheel whereas with the chainring on the outside of the cranks I get more like 52mm at the chainring. I don't know exactly what the model Sugino cranks are, but does the fact that they have shoulders for mounting the chainring on both sides mean that it's a double rather than single?

Runs beautifully but obviously looks slightly wrong as the chainring is on the inside. Doesn't look like theres enough space for a much shorter BB. Any tips other than changing the cranks?

I've clocked up about 100 miles on the bike this weekend so here's the first road report. All my observations are compared to my Condor Pista steel frame as both frames have an identical geometry and similar sort of components.

It handles pretty much identically to the Pista frame in cornering and general maneuverability. On the straight it also feels similar. I can't really feel any significant loss in speed compared with the Pista but it is noticeably smoother and more comfortable. I think the internal damping within the wood absorbs general road vibration very well and gives a very smooth ride. It is also by far the quietest bike I've ever ridden. The only noise is an eerie whistling that comes from the spokes in the front wheel over 23mph. Never had that before.

I haven't measured the lateral stiffness yet compared with the Pista frame but it doesn't feel nearly as lively when I get out of the saddle on hills which makes me think it is probably a fair bit more flexible. The frame is a bit heavier (I haven't measured that yet either) but I was riding without a water bottle and that's about the same as the weight difference so I doubt the weight is the reason it feels different. The rear stays do feel quite a bit more laterally flexible than a steel or alu frame so this is probably the reason. If (when) I build another one, I think I'll try filling in the gap between the seat stays all the way down to the wheel to stiffen up the back end. Alternatively making them a bit thicker would do the trick but I don't want it to look too heavy.

One other thing that I'm going to have to get used to is the size of the top tube. At 50mm wide it is a lot bigger than any bike I've ridden before and I tend to rub my knees on it especially when out of the saddle.

I'd like to go to Regents Park and do some back to back laps with the 2 bikes to see how they compare.

Overall, it rides reassuringly similarly to the Pista frame and I'm pretty pleased with how it's turned out.

See you stuck with the gold chain.
Yes, the chain was sat there and I really wanted to get the bike built up! The chain does kind of match the central maple layer and I suspect it might not look bad when it loses its initial shine.

Still on the fence about it though.

Also I would have swapped the levers/cabling, but I gather you brits like to have the front brake in the right hand....crazy.

Didn't know anyone else did it differently!

this is incredible; I was thinking of making one from bamboo, but this looks much much nicer...

I think it looks nicer too. There are very few good looking bamboo bike home builds from what i've seen. As sustainable as it might be I hate the hemp twine joints that everyone seems to use on the bamboo joints. Looks like a kids design technology project. There are some lovely carbon jointed frames though.

I thought about a bamboo bike myself and did plenty of research before I decided on this one but using hardwood is a hell of a lot more labour intensive as it takes a long time laminating and shaping the frame by hand where as with the bamboo the tubes are already formed for you.

Took some better photos in the sun this weekend. Unfortunately couldn't take it out for a spin as there are still some minor tweaks.
Plenty of high res photos on my website.
http://ligneusbikes.wordpress.com/hardwood-single-speed/photos/

Did some jumping around on the pedals to do some very crude strength/ stiffness checks. Will report back when I hit the streets on it (hopefully not literally).

Yew lot think this is all a j'oak and are just Teaking the Hickory. But I Walnut let Alder wood based Pines derail this thread and am determined to get everyone to Cedar point in wooden bikes.

My thinking was to leave all the components completely plain and black to show off the frame. They were also all very cheap off classifieds and when I got them for the build I didn't know how it would turn out so didn't seem worth wasting money on it.

I think the chunky carbon forks work well to match the rear triangle and balance the chunky frame tubes so they're a keeper for me. But now I think it could look really nice with silver wheels, stem, seatpost, bars. With a Brooks saddle and leather/ cork bar tape and I do think that gumwall tyres are a good shout.

It's going to stay in it's current guise in the near future as I don't have the money to start chopping and changing components. But it may have a face lift further down the line.

No, it's a waterslide decal printed on an inkjet printer which then went clear with the varnish

One more photo

After weeks of neglect, the wait is almost over. First build up this evening and I can't deny that I'm feeling rather smug. Looking like a real bike now, and not a bad one at that. First ride and better photos to come on Sunday.

I bought a gold chain for it which never even came out of the packaging. What was I thinking?

And the head badge is half finished but needs some more time.

You need to factor in the weight, 80kg in says a 5mm square contact point vs. 80kg in a 1cm square - which would you reckon spread the weight evenly?

Pressure = force per unit area

Bigger tyre = bigger contact patch

Common misconception. In fact the pressure between the road and the tyre is pretty much exactly the same as the pressure you inflate the tyre to whatever tyre size. If you put more weight on the tyre then the contact area spreads out to keep the same pressure.

So, for a larger and smaller width tyre at the same pressure with the same rider they will have the same contact area. The key to rolling resistance is the shape of the contact area (I suspect Tester has already covered this but here it is anyway). The thinner tyre has a long thin contact area whereas the wider tyre has a wider shorter contact area.

Rolling resistance comes from the losses caused by internal friction in the tyre and between the tyre and inner tube so the more you bend the tyre, the more energy you lose. If you imagine the contact area as a flattening of the circular shape of the tyre against the road then you can imagine that it's much harder to flatten a long thin strip than a short fat strip because of the curvature of the tyre. So the long thin strip causes larger energy losses in the tyre (at the same pressure). For the same reason, larger diameter wheels have lower rolling resistance due to the increased curvature of the tyres and higher pressure reduces the length of the contact strip and will also reduce rolling resistance (on a hard surface)

But it's all a play off between aero, weight, rolling losses AND comfort so there's no one size fits all answer.

I will just use my assumption based physics (what can go wrong with that)
If you read the post then it won't be assumption based!

This is the reason I wrote it in the first place because you are only seeing half the effect. The second half is not quite as obvious and is entirely dependant of the height of COG.

A body of weight further away from the point where the front wheel touches the ground is going to take more effort to lift due to basic leverage.
Right

Centre of Gravity doesn't matter
Wrong! You've just told me it does matter (horizontally) in your last statement.

If the rider sat 100 metres back from the front wheel it doesn't matter how much higher they are sitting, they are not going to be lifted as easily.
Wrong. If the seat was 200m high then it would be considereably less stable than a normal bike.

There is only 1 equation to compare the different situations (the first equation for deceleration in the post), and it's very simple (calculates acceleration/ deceleration but that's essentially the same as stopping distance).

It's an interesting one though. Going back to the lo-pro question on the last page, it does feel like you're overbalanced further forward and are more likely to go over the handle bars as you're leaning forwards so much. I suspect that you actually shift your centre of gravity downwards by a greater proportion than you shift it forwards compared with a normal riding position as you're basically just rotating down around your hips. Counterintuitively this would make it more stable than normal. Don't know if that's actually the case though.

My 'halves braking distance rule' number was based on my own riding position on the drops. If you ride a bike with a different geometry, say with risers, then your centre of gravity will be higher and it will reduce the effectiveness of the rear brake further.

There is also a discussion on the link about how you initiate a skid in the first place and how it changes braking distance. People tend to shift their weight forwards to make it easier to initiate the skid. The further forwards you lean the further you'll skid.

So, depending on how you skid, it can only be worse than the 2x number. I was trying to show best rear wheel braking vs best front wheel braking.

What are the physics behind doing "whip skids" and pushing the back wheel out to the side?
I guess it would be exactly the same as a normal skid. It all depends on how far forward or back your bodyweight is. It could be that you naturally lean back a bit more as you whip skid so you get more weight on the back and slow down quicker.

Does science agree that it makes you stop faster? Can you use science to test whether it makes you look cooler?
Yes. Linear relationship between angle of bike relative to the road and level of coolness. Unless you happen to hit something or something hit you because you should have use the front brake instead!

If your brakes are working properly, there will always be times when the quickest stop is the one where the back wheel is barely touching the ground. You need to be able to keep the back wheel there, neither pressing on the ground nor lifting far off it, whatever bike you're on. If the first time your back wheel comes off the ground is when a car pulls out in front of you, you will probably go over the bars, so practice somewhere quiet with nice grippy tarmac so you don't get surprised at the worst possible time.

There are circumstances when you can't use the full power of the front brake, in which case having a back brake can make a small additional contribution, so if your frame has fittings for a back brake, always fit one, whether you're riding fixed or free. Not doing so is the dumbest kind of false economy.

Tester is, as usual, right. I haven't followed the previous 42 pages of this thread but, in a pub debate, someone will always have their 'opinion' on the best way to brake. I've often tried to explain (after a few beers) that front wheel braking is the ONLY way to stop fast in an emergency and that you should adopt it as your sole braking method when riding normally because, as Tester says, you don't want to learn in an emergency.

So, I thought I'd write a quick piece on Physics for Hipsters explaining the theory behind front wheel braking. Hopefully in laymans terms. http://ligneusbikes.wordpress.com/2012/04/23/brakeless-clueless/

If you can't be bothered to get to the end (or even the start) then the answer is that** front wheel braking, fixed or non-fixed is 2 times more effective than back wheel braking in an emergency stop**. So riding brakeless automatically halves your braking capacity even if you're totally switched on and can stop whenever you want to.

It should also be a lesson for all the rear wheel brakers to start to learn to use the front wheel brake more effectively as you might just need it one day!

Bull horns would be easy to modify to have the curve up at different points. Or as an interim measure, you could just hold the horns in different positions.

Alternatively, assuming you're on drop handlebars, how about using different sized hoods on each side of the bar. Some hoods are bloody massive and would give you at least 2.5cm compared with a small hood.