LONDON, England (CNN) -- As far as modes of transport go, it has to be one of the most environmentally friendly: a cardboard bike that can be recycled, in all senses of the word.
University student Phil Bridge says his cardboard bike could last six months with everyday use.
And before you pipe up about the weather, the inventor of this recyclable bicycle insists that his creation won't collapse in a soggy heap at the first sign of rain.
University student Phil Bridge, 21, didn't set out to create a cardboard bike. He approached the final project of his Sheffield Hallam University Product Design course with the intention of encouraging more people to cycle.
"I realized that one of the biggest issues in Britain was the initial cost of a bike," he said. "Also, people are concerned about leaving their bike outside in the street chained to a lamppost; will it be vandalized or stolen?"
He decided to make a bike that was so cheap, thieves wouldn't be interested in stealing it.
On that count, he has succeeded. He estimates that the cardboard bicycle costs about $30 to produce.
"The expensive bits are the metal components," he said. "I could do the frame, the fork and the wheels for about $8 -- the cardboard components -- all finished and assembled."
The idea is that the cardboard components would be replaced every six months free of charge.
The hardier elements -- the steel wheel rims, crankset and tires -- would simply slot into a fresh cardboard frame.
So far, few have had the privilege of taking the recyclable bicycle for a spin. The first prototype was "half-ridden" around the university in Sheffield, northern England, as part of initial testing. The current version is a visual prototype that's being displayed at Creative Spark, an exhibition of work by the university's graduate students.
After the exhibition, Bridge plans to build and road test a fully working prototype.
"We'll see where it goes from there," he said.
The frame is made from a heavy-wearing cardboard called Hexacomb, which is impregnated with a waterproofing agent at the point of manufacture.
The manufacturers use the same type of cardboard to make pallets that they say are capable of handling loads weighing up to 2,500 pounds.
Bridge puts the weight limit for his bicycle at about 12 stone but says the frame could probably be strengthened for heavier cyclists.
"The best application is in children's bikes, because you have less stresses involved," he said. "Families could afford to change the frame every year as the child grows."
At this stage, it's just an idea. Bridge has no corporate backing or plans to launch his cardboard bicycle as a private venture.
Right now, the top priority for the graduate is finding a job.
"I need to get some money behind me. After university, there's not much money left," he said, adding, "I may continue to pursue the cardboard bike in my spare time."