Introduction: LIGNUM BIKE DIY

Do-it-yourself offers an alternative to anonymous objects from the industry. When we do DIourselves, we are not only spectators and consumers.

We participate, we try to recover know-how, we do as much as possible by ourselves and we leave the immediate world of purchase. The "lignum bike DIY" is an alternative to the industrial standardized bicycle.

This work questions the limits of handcrafted works and asks:
Can we create ourselves without industrialization an equivalent object to what we find in the market ? Is there a limit to self-construction ?

Step 1: Tell Me Who You Are and I'll Tell You What Your Bike Is

We must begin by identifying our needs to determine the characteristics of the bike we want.

In my case, I come to the conclusion that the type of bike that best suits my use is the “urban” bike. It corresponds to a road bike close to the racing bike profile, with a straight fork and without dampers. I also want a short bike, the lightest possible, quite nervous, with a trail rather small to have good maneuverability and a chainstay less than 420mm, so that it is easier to make ascents.

To guarantee appropriate and ideal measurements according to your physionomy and the search criteria you need special knowledge. Wishing to avoid errors due to my inexperience I chose to refer to dimensions that I know well; that of my current bike. Then, based on the proven feelings of comfort, experimenting and comparing my posture on other bikes, I made some adjustments and improvements.

Step 2: "Lignum" Wood in Latin

Some examples of wooden bicycles :

It was clear for me to use wood as building material.

From an artistic point of view, it is handy and offers possibilities of free curved shapes and a wide choice of essences (texture, colors,...) which make it a very interesting material to work.

Wood derived from a natural and sustainable resource. It has many interesting characteristics and structural qualities for a variety of uses and functions. It is solid, flexible, lightweight, easy to handle, easy to machine. The wood also has a long-lasting resistance to shocks if properly maintained over the time.

Its main strengths is the ability to work it manually by using simple tools that can be easily found or borrowed.


Step 3: A Broom's Handle for the Handlebars...

I opted for a constructive method called sandwich-structured composite to make the bike's frame.

This system makes it possible to create a piece with uniform mechanical properties as a massive board and also has the great advantage of considerably reducing the weight (density of the material used).

At the same time resistant in bending and in compression, this system offers a high strength that its components individually do not have.

This sandwich composite consists of a balsa core (very light and porous wood) caught between two skins of aviation birch plywood assembled with epoxy glue.

I then decided to cover the balsa with a layer of fiberglass and epoxy glue to avoid punch marks and to rigidify the system.

Step 4: Now, Just Take a Pencil and a Sheet of Paper to Find the Design of Your Bike.

Step 5: Shopping List

Step 6: Frame

Step 7: Fully Assembled Frame

Step 8: Seatstay and Chainstay

Step 9: Fork

Step 10: Finishing Work

Step 11: Finished Bike

Step 12: Conclusions

This project allowed me to test my capacities and my autonomy against products developed and sold all finished on the market, to learn to use tools, to make manipulations (epoxy, collage) and especially to be able to apply theoretical knowledge about a tangible object.

Prior knowledge has been useful and necessary to carry out this project.

This project confirmed that you can bypass the "all made, ready to consume" and create unique objects.

I understood what was reasonably possible to do myself in a given time and using common materials and tools.

In the case of bicycles, technical parts (bearings, wheels, axles, ...) mark the limit of the DIY, requiring know-how and specific tools too expensive for a one-off piece of craft.

But above all the DIY is the opportunity to create a unique, personal and rewarding object.

Acknowledgments:

The succes of this project would'nt have been possible without the encouragements and support of Philippe Spahni, advice and assistance of Peter Gallinelli, Stéphane Voeffray and all the people I talked to, who shared their knowhow and who helped me, especially Bosbikes, Péclot 13 and Corabois.

Publications:
Article in Le Cahier Genevois (Pro Vélo) by Claude Marthaler, May 2015, follow this link

« A tire-d'elles ; femme, vélo et liberté » by Claude Marthaler, Slatkine edition, 2016