Wooden Bikes
Fun Bikes that you can make yourself, from wood and metal

Pencil Bike   Mini Bent Bike   Bamboo Coaster Bike  

Wood Suspension Bike    Scooter Bike    Driftwood Bike    Converted Bike    Ski Bike

  Hammock Seat Tandem    Unicycle Scooter    Rear Captain Tandem    Compact Bikes    

Adjustable Head Bike  Plywood Wedge Bike    Lawn Mower Bike  Wood High Wheeler    Scooters    Triangle Bike 1

Office Bike    Triange Wedge Bike     Wood Draisine Scooter   Wood Bounce Bike

 How I started   Bikes Built by Others    Q & A  Workshop    Books and Links

 

So you want to build a bike in the worst possible way... 
My epiphany came when was trying to make a large castor wheel for a parade float.  I drilled a hole in a scrap of redwood 4x6 lumber and mounted an old Campagnolo bike headset in it.  I installed an old bike fork through it and attaching a wheel to make a BIG castor wheel.  But many other possibilities emerged.  I was also immediately captivated by the incongruous look of an old piece of lumber sporting a fine headset and supporting a fork and wheel.

To listen to a podcast interview about wooden bikes, Click Here.

It reminded me of antique wooden boneshaker bikes from the 1800's and even older wheeled wooden swift walkers or Draisines that I have seen in museums and bike books.  It made me realize how easy it would be to build bikes now that we have ready access to headsets, Bottom Brackets (BBs) and wheels.  I realized that the recumbent (laying back with feet out front) bike frame design was an easy way to use a single piece of wood for the main frame with no joints.  I could simply use a piece of plywood on each side, taking the place of seat stays and chain stays, to support the back wheel.

My first two bikes are built around redwood lumber 4x4s. My third is a semi recumbent built around a sloping 2x4. The 4th is made from a driftwood log in a beach bike theme.  I hope you will find that as you build bikes and ride them, you get many new ideas.

 

Some Construction details:
How are the bars attached to the fork?
I've done several variations.
1) I passed a 4" hardened steel (Grade 8) 1/4" bolt through the brake mount hole and through a cheap (seat to seat post) clamp that holds the beach cruiser bars. This only pins the bars in two dimensions. If you stop there, the bars can still pivot around the horizontal bolt axis, which is remarkably disconcerting. So the next step is to drill a couple of holes through the fork through which to pass 3" u shaped bolts that secure the bars to the fork in more locations. This method puts holes in the fork but not in the bars. This keeps the bars strong.

2) With bars like BMX bars (that have the cross bar welded into them for support) I have clamped them like the center part described above. But I felt comfortable drilling a hole about 2" out from he center on each side (and through the fork) to pin them with 1/4" hardened bolts.

3) I have also used long hose clamps wrapped twice around the fork and bars on each fork leg.
4) I have also used a diagonal tube brace from one bar end down to the fork's fender mounting eyelet for support.

 

Bar Mounting Misc.
I have mounted a short piece of 2x2 wood between the fork and bars to move the bars 2 inches back within closer reach.  I also have mounted the longer bar end extensions onto the ends of the handlebars to bring my and position closer and to provide some adjustability as needed.
I confess to cutting an old rim in half (semi circle) to make semi flexible handle bars for one bike. 
I replaced that with a bent branch cut off a eucalyptus tree (high weight to strength ratio) for a more primitive look and to improve the handlebar rigidity for improved control. 

How is the Bottom Bracket (BB) mounted to the frame?
I've done several variations of mounting the BBs through the wood frame.
Keep in mind the goal of leaving maximum wood fiber in place for strength. This is done by drilling the reuired holes with the smallest diameter or shortest depth possible to leave maximum wood intact.

I find that 3 piece "cotter less" crank BBs cups can be threaded into wood, but they tend to work loose, since pedaling forces rock the BB axel wthin the curved cups thereby forcing the cups apart.  I have had partial succes with installing cover plates of oak or sheet metal over the cups (with a hole drilled for the axel to pass through) and screwed to the frame to hold the cups in place and to keep them from being wiggled apart.

For 3 piece "cotter less" crank BBs I drill holes in the wood in the following order:
a) 1/4" pilot hole drilled with my 15" long bit for sighting accuracy. (important tolerance is be perpendicular to chain line).
b) next use an appropriate tight sized hole saw drill to cut about 3/4" in on each side for the BB cups. Do not chisel away the wood in the center yet.
c) Use 5/8" spade bit to follow the pilot hole all the way through (so you can fit the axle).
Now you can chisel away the wood in the center of the holes sawed in step b) down to the 3/4" depth.
Thread the right cup and race into place. Assemble the BB.
I find I have to put a 4" wide and long plate (oak or sheet metal) over the cups and secured by screws to the frame in order to keep the cups from working loose.

I find that for wood frames the 1 piece cheapo (Ashtubula) crank set is a good match since it holds itself together and puts the wood in compression.

For One Piece "Ashtubula" crank sets I tap the cups out of the donor frame and drill holes in the wood in the following order with a focus on maintaining maximum remaining wood strength:
a) 1/4" pilot hole drilled with my 15" long bit for sighting accuracy. (important tolerance is be perpendicular to chain line).
b) next use an appropriate tight sized hole saw drill to cut about 3/4" in on each side for the BB cups. You can chisel away the wood in the center of the holes sawed in step b) down to the 3/4" depth.
c) Use 5/8" spade bit to follow the pilot hole all the way through.
d) use 5/8" spade bit to drill a hole right next to and parallel to hole c). (Arrange them parallel to the grain to cut the fewest wood fibers)
e) Chisel the 3 holes into a smooth slot (so you can pass the crank and axle through the slot).

Put the right cup and race in place first
Maneuver the crank into place and then slide the left cup and race into place over the crank.
Assemble the BB.

Good luck.

History

 

tomkabat@aol.com

Woodenbikes © 2004 - 2008 All Rights Reserved

Wooden Bikes Home Page