I’m dying to give you more advice here, but I really hesitate to interfere with your artistic concepts. I’m gonna stand back and watch the glue fly!
Wooden bicycle build
- Thread starter BartRidesEternal
- Start date
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I have some options (brackets on the steel frame among them) on the table which does not require wood turning. But its no problem if you give advice Ulu, love to see other views from another part of the world and very thankful for all the advice so far
As mentioned before, in my job as mechanical engineer, I work with a set of requirements (temperature, shock, vibration, corrosion and general use) and the design grows from those set of requirements.
In this build, I use a different set of requirements and I want to mess around with stuff that is available to me:
- The bicycle has to be rid-able and strong enough most of all.
- I am trying to make something beautiful, something people can look at for quite some time and talk about all the details.
- The bicycle has to look good and I'm trying, where possible to utilize the oldschool fabrication methods, so the bicycle looks antique as well. At least that is what I am going for.
- Have fun is a requirement! Having fun so far.
- It does not have to be practical like a commuter regarding racks and weather conditions. I don't want an cardboard bike either.
- The bicycle must be repairable like any other bike.
- And the budget. I am not building 1K euro bicycles to build.
- Technically, mechanically sound. No squeaks, rattles, bad bearings and a low efficiency.
If I were to give you a bit more advice it would be this. Look at the FEA charts of a typical bicycle frame under stress, and for the sake of artistry, do not limit yourself to cylindrical sticks of wood. There is no structural requirement for them to be cylinders.
Just needs some stickers. 
Just to give you even more options, I found this one on Boatbuilder's/Camper Plans site:
Thanks for sending a passionate woodworm/bike builder/camper down THAT rabbit hole...Just to give you even more options, I found this one on Boatbuilder's/Camper Plans site:
Smashing the Hoopy
Thats true, though bicycle tubing is usually round since that is the stiffest regarding torsion.
You probably already know, but thats why these lighter modern crankshafts (and frame tubing) is larger in diameter. You have a stiffer shaft or tube with a thinner wall and similar weight. I can show that with some equations, but I guess you'll understand what I am talking about with your knowledge
Wow that is gnarly! Thanks for that share Kevin B.
Thats a cool bike and website. The guys builds everything with wood. Boats, bikes, trailers. I'll take my time to read that tomorrow. Thanks!Just to give you even more options, I found this one on Boatbuilder's/Camper Plans site:
Ouch! That thing is incredibly tough. Especially the headtube.
Since the pieces don't fit in the turning machines that are available to me, I had to think about an alternative method for the downtube to bottom bracket connection.
I decided to laminate a smaller piece, four stacks, with two stacks sticking out enough for a solid lamination. Then, laminate and glue the rest on there. The first picture below gives an impression of my description.
Remember, two pieces can easily hold my weight in the direction of the weaker 10mm (flat) side on a distance of 40cm.
Top tube to seat tube connection will be made fit by drilling. The steel section is 1 inch in diameter. Alignment and a drilling jig is key.
Four pieces fully sanded! A lot of work to get the hard white glue off.
First lamination piece!!
The 'four stacks high' bit will be round 32mm when I am done wood turning. And it will fit inside the frame tube there.
I will glue and rivet/screw it after alignment in the frame.
@Ulu
I wonder how the rivets in the below picture you sent earlier, are expanded in the wood. Is the wood that hard or the rivets that soft?
Or are they held in by a weld or even a tight fit in the wood?
Thanks guys!!
I decided to laminate a smaller piece, four stacks, with two stacks sticking out enough for a solid lamination. Then, laminate and glue the rest on there. The first picture below gives an impression of my description.
Remember, two pieces can easily hold my weight in the direction of the weaker 10mm (flat) side on a distance of 40cm.
Top tube to seat tube connection will be made fit by drilling. The steel section is 1 inch in diameter. Alignment and a drilling jig is key.
Four pieces fully sanded! A lot of work to get the hard white glue off.
First lamination piece!!
The 'four stacks high' bit will be round 32mm when I am done wood turning. And it will fit inside the frame tube there.
I will glue and rivet/screw it after alignment in the frame.
@Ulu
I wonder how the rivets in the below picture you sent earlier, are expanded in the wood. Is the wood that hard or the rivets that soft?
Or are they held in by a weld or even a tight fit in the wood?
Thanks guys!!
The wood is pre-stressed & compressed by the rivet.
The stick is shoved into the ferrule hard. Until the wood almost starts to yield.
An undersized drill bit is run thru each hole, then each pre-headed rivet is pressed thru hard, and peened over with an arbor press.
The rivets aren’t hard on the end until the peening work hardens the tip.
They don’t have to be large in diameter, because the wood is so much weaker than metal. It would fail first.
Making the rivets/bolts large diameter for style would weaken the wood further. 4mm bolts would probably be plenty thick if you use enough. Will the steel be over 2mm thick? My thinking would be to use a minimum of 3 small bolts (or more) per connection, properly staggered and oriented to reduce splitting.
In your case, don’t put the screws or rivets all from one direction. They help maintain the shape of the steel pocket or ferrule, under stress. Smaller and more will be best to distribute stress and achieve a direct load path.
The tapered ferrule design reduces the steel thickness needed while minimizing stress on the wood. It doesn’t need to be round in section either.
Round is strongest for the ferrule, but the wood will be your real concern.
The stick is shoved into the ferrule hard. Until the wood almost starts to yield.
An undersized drill bit is run thru each hole, then each pre-headed rivet is pressed thru hard, and peened over with an arbor press.
The rivets aren’t hard on the end until the peening work hardens the tip.
They don’t have to be large in diameter, because the wood is so much weaker than metal. It would fail first.
Making the rivets/bolts large diameter for style would weaken the wood further. 4mm bolts would probably be plenty thick if you use enough. Will the steel be over 2mm thick? My thinking would be to use a minimum of 3 small bolts (or more) per connection, properly staggered and oriented to reduce splitting.
In your case, don’t put the screws or rivets all from one direction. They help maintain the shape of the steel pocket or ferrule, under stress. Smaller and more will be best to distribute stress and achieve a direct load path.
The tapered ferrule design reduces the steel thickness needed while minimizing stress on the wood. It doesn’t need to be round in section either.
Round is strongest for the ferrule, but the wood will be your real concern.
Thank you @Ulu , tomorrow I am heading to a local tech shop that might have these rivets.
Reminds me a bit of this:
A few updates, I made the first piece near the bottom bracket round. 31,9mm.
Had it the other way round in the lathe at first.
Centrered and clamped!
In due time I will align it, and hammer it in with glue. Add some screws/rivets.
And I saw this beauty on the internet, dreaming about new builds...
Reminds me a bit of this:
A few updates, I made the first piece near the bottom bracket round. 31,9mm.
Had it the other way round in the lathe at first.
Centrered and clamped!
In due time I will align it, and hammer it in with glue. Add some screws/rivets.
And I saw this beauty on the internet, dreaming about new builds...
