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2007.10.13 SANOMAGIC Wooden Bicycle
Sueshiro has started building a mahogany bicycle from autumn 2007. By applying
his wooden-shipbuilding technic, Sueshiro intends to manufacture a road
bike lighter and faster than those comprising metal frames. First prototype
under construction has a solid mahogany laminated frame. Second prototype
will have a hollow (tubular) mahogany laminated frame. The first prototype
will be completed by the end of 2007.
After three months has passed from the departure of SUN-OH-MARU, a bicycle
frame of mahogany color has appeared in SANOMAGIC.
The frame was assembled with laminated bodies formed by combining mahogany
Front part of the frame and front fork.
This frame was lighter than I expected from its appearance. Even in this
stage, it maybe lighter than conventional metal frame. According to bicycle
engineer who had conducted bottom bracket processing of this frame, this
frame has an excessive rigidity as a bicycle frame.
Super duralumin plates of 6mm thick are firxed on front and back fork ends.
Seat tube is formed by laminating thin mahogany sheet on a duralumin tube.
The upper part of the seat tube consists of a duralumin tube, and the lower
part of the seat tube is formed by a laminated body consisting of mahogany
The curved portion of the front fork is formed by bending laminated mahogany
Sueshiro mounted on the lower ends of the front fork. But the front fork
did not deform at all.
Head tube is consisted of a duralumin tube.
Plane view of the head tube.
The front end portion of the frame supporting the head tube has a large
At the front end portion of the frame, about 30 mahogany plates are combined
to produce a high rigidity.
Plan view of the front fork
Though the frame and front fork are solid, weight of the mahogany laminated
body is relatively small.
According to Sueshiro, it is very difficult to combine mahogany plates
while bending the plates to a small curvature radius like this.
The bending portion of the front fork has a laminated structure like this.
Front fork is detached from the frame.
The white lower ends of front fork will be painted to some color.
Super duralumin plates are inserted into mahogany laminated body, rolled
with fiber sheets, and fixed by adhesive.
Frame is now coated with varnish for dampproofing. However, the frame will
be whittled later to reduce the weight and improve elasticity.
The upper end of duralumin seat tube.
Bottom view of the assembly of frame and seat tube.
Cirsumference of bottom bracket.
Can you imagine how to assemble this part?
The bicycle engineer engaged in processing of bottom bracket has assured
that this frame has a very strong regidity for supporting the bottom bracket.
Circumference of the bottom bracket.
Top view of the circumference of the bottom bracket.
Rear end portions of frame. Super duralumin plates are embedded in the
mohogany laminated frame.
Sueshiro brightly explains each part of the frame.
The mahogany laminated body from which the frame was shaped
Plane view of mahogany laminated body. Twenty mahogany plates of 2 mm thick
have been combined to each other.
It is difficult to bend mahogany plates while combining them during the hardening of adhesive.
The manufacture of the frame required a mahogany lumber like this. What
an expensive frame!
Thin films of sliced mahogany. Second prototype may be constructed using
Films are suspended from the ceiling for preventing curling.
Sueshiro's bicycle for daily use comprises a seat post made by laminating mahogany.
This mahogany seat post produces soft cushioning.
I tried to ride this bicycle and found it very comfortable.
"This seat post eased my lumbago", he said.
Sideboard under construction in SANOMAGIC.
Inlaid work of the sideboard
Design drawing of the sideboard. Curved frames are characteristic.
These are the arc frames. Each frame consists of laminated mahogany plates.
Method for forming the arc frames.
You can see lamination of mahogany plates.
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