Another wooden bike

In a previous column I wrote about a wooden bicycle project that I found on Instructables.  I thought it featured some clever design features, but of course it wasn’t made completely from wood.  Only the frame is wood, the fork, crank, chain, wheels, etc. were all conventional metal bike parts.

But it turns out that there is an all wood bicycle, being built in Norfolk UK, as the result of a bet of one UK pound.  Eco builder and woodworker Michael Thompson was watching the Tour of Britain zoom past his house with his friend James Tully when he made the statement that he thought he could build a bicycle entirely out of wood — no screws, bolts, bearings, or other metal parts.  Just wood, glue, paint, and varnish.  Tully took the bet and said that if the bike was built, he would ride it.

Over 1000 engineering hours later the Splinter Bike is nearly ready, and the ride has been turned into a quest to achieve the worlds speed record for a wooden bicycle.  It shouldn’t be terribly difficult to set the record, as there currently isn’t one.  If successful, not only will the team end up world record holders, they and their sponsors will also have raised some money for the UK charity Shelter Box.

Most of the bicycle is built from birch plywood.  Other woods were chosen for their specific properties depending on where they were used:  Ekki for the axles, ironwood to form bearings wherever moving parts have contact, and an old broom handle for the handlebars.

How about the chain?  It doesn’t have one.  Instead there is a gear attached to the crank, which turns a much larger 128 tooth cog, which turns a gear built into the hub of the rear wheel.  This drivetrain is duplicated on both sides of the bicycle to keep the forces balanced, and you can even change the gear ratio, although you have to swap out the rear wheel to do it.  Maybe  Splinter Bike 2.0 will have a wooden planetary gearset.

Tires?   It has the world’s lowest profile tire, and the only one made out of glue.  Thompson chucked the wheels up in a lathe and applied a 3mm thick coat of Evo-Stik Serious Stuff Ultimate Power Adhesive.  It apparently dries to a rubbery finish and is durable enough to serve as a tire for this bike.

According to the Splinter Bike blog, the bicycle is now complete and the team is waiting for enough donations to come in to be able to attempt the speed record.  It’s apparently fairly expensive, around $10,000, to certify a land speed record.  They expect the record to be around 31 mph, by the way, using the rear wheel with the 4:1 gear ratio.

Steve Ravet

Design News Gadgeteer