Splinter Bike - a bicycle built ENTIRELY out of wood
Just over six months after making a joke bet in his front garden, Michael Thompson has lived up to his idle boast of being able to make anything out of wood. Unlike other bike designs where wood is just one of several materials used in the construction – like the duo from Audi and Renovo, which has a hardwood frame – every part of the Splinter Bike is made from either birch plywood, Lignum Vitae, Ekki or an old broom handle. Thompson's friend and accomplished triathlete, James Tully, now has the unenviable and certainly uncomfortable task of riding the 31 kg (68 pound) engineering marvel into the record books.
The inspiration for the small wager, and the subsequent build project, came as the Tour of Britain race went through Norfolk for the first time last September. Now, after over 1,000 hours locked in his shed made of earth, Thompson has emerged with the Splinter Bike – a 100 percent wood, glue and paint bike.
Many of the furniture grade birch ply components, including the cogs, frame and wheels, were made by hand, the latter also having about 3.5mm (0.13-inch) of Evo-Stik Serious Stuff Ultimate Power Adhesive applied to each of the three wheel rims to provide some grip when dry. Two gear options have been developed – with 4:1 and 3:3:1 ratios that's said to result in the rear wheel rotating 3.3 or 4 times for each revolution of the pedal. Tully won't be able to change gear without swapping wheels, though, so he'd better make the right choice before the record attempt.
Hidden behind a pear-shaped design at the rear is the bike's drive system. "The drive is very simple," Thompson told Gizmag. "Instead of sprockets at the rear hub and the chainring I have replaced them with plywood gears and instead of connecting them with a chain I have used a 700mm diameter, 128 tooth plywood gear, known as the pliCog. This 3 gear drive is replicated on each side of the bike. The whole thing runs like clockwork, literally."
Where moving parts meet, oily Lignum Vitae hardwood has been used in place of metal bearings to minimize friction. The axles are made from reclaimed Ekki and the pedals and handlebars fashioned from an old broom handle that was unlucky enough to be laying around the Eco-Shed.
The all-wood steering mechanism is described as a chunky plywood butt hinge and Tully's favorite triathlon bike seat was used as the template for the ply and MDF seat, custom-shaped for a snug fit. Thompson informed us that his "crank is not much different to a regular one, apart from it being replicated on both sides and made out of wood."
A static test run in December saw an early build achieve 350 rpm (without resistance), which was worked out to be 28.96 mph (46.6 kph). The project aim is to reach – and hopefully exceed – 37.6 mph (60.5 kph).
By the beginning of April, the Splinter Bike was painted and branded to tie in with the Shelter Box disaster relief charity color scheme, for which the team hopes to raise some funds.
The wooden bike's designer and creator told us that although extensive testing has been undertaken on the bench, "as of yet, we haven't tested the Splinter Bike with James on the track." To get accustomed to pedals that are always moving when the bike is motion, Tully has been given a Harry Quinn fixed-gear bicycle from the 1960s to train on.
Thompson constructed a version of a Renovo stand to best show off the bike for a recent photo shoot before starting on the second half of the project – raising money and searching for a suitably flat venue for the attempt at the first land speed record for an all-wooden bicycle. "We have a few venues available to us, mostly outdoor velodromes," says Thompson. "We are hopeful that we end up setting the record at the new 2012 Olympic Velodrome."
Malcolm Pittwood from the Speed Record Club will time Tully as he pedals the Splinter Bike as fast as he can for 250 meters (820.2 feet) around the track. The rider is allowed a 15 meter (49 feet) push start and an unlimited build up distance before recording begins.
The Splinter Bike team has set its sights on making the attempt before September this year, when Thompson told us that the bike will be going on display at the Victoria & Albert Museum in London as part of an exhibition called Power of Making from September 2011 to January 2012 and then it will be going on a UK tour of 3 or 4 other museums from February 2012 to February 2013.