With a fair bit of trepidation, following my abject failure to finish the Midge project, I have decided to announce my latest and probably most absurd project to date (probably not as absurd as the Mad Max Volvo Pickup I was building which ended when I broke my back running out of talent whilst mountain biking on Cannock Chase)
So without further ado, here is the future of urban personal transportation, The Thunderbug Trike
All right I will be the first to admit it looks like a box with three wheels magically suspect in a vertical position but it is a start.
I have been tinkering with the idea of building a trike for a number of years but was always put off by the fact that using steel would make the trike weigh around 40lb and that aluminium was just too difficult to work with without specialist equipment. I have also been tinkering with the idea of using bamboo as a frame material as I have the tools to work with wood (or grass) and just about enough skill to get me through. Some may remember the plywood recumbent me and Connor built two years ago whilst I was convalescing from my road accident. Indeed the seat and rear wheel have been salvaged from the back of the shed as temporary props for the Trike.
Whilst the bike made very interesting riding, it did prove that wood would work and that I would be able to ride a bike again as up to having my second operation riding an upright bike was out of the question.
So fast forward to the present and the urge to have a go at a trike had reached the top of the pile of things I wanted to try and build. In the intervening years it appears that composite materials are now readily available in the home user environment. There is a wealth of information out there and a number of suppliers happy to provide no minimum quantities to enthusiastic amateurs. There is also a growing number of people building bamboo bikes and whilst the knowledge required is generally more guarded by those in the know, probably because there is an abundant number of hipsters willing to part with loads of money for their ‘boo bikes.
After researching what is out there and buying a number of books (including the excellent “The Cycling Zoo” by Steve Nurse and “Bicycle design” by Mike Burrows I decided on doing away with the typical bike frame in favour of a monocoque chassis, after all in my mind a trike has more in common with a car (or a three wheeler) than a bike and with the use of composites it made sense to build a monocoque utilising the inherent strength of the materials, the weight saving benefits and the simplification of the build by bolting the components to the tub. The more I thought about it the more it made sense and would allow me to dabble with new skill sets.
The design has come along and will be an amalgamation of natural and man made fibres, bamboo for the front wishbones, pedal boom, rear arms and seat, carbon fibre for the tub and supports, aluminium for the brackets and links. I have incorporated four link shock absorption on the rear ( I wouldn’t dare call it suspension but hopefully it will take the pain of the bumps away) and I have ovalised the bamboo to utilise more substantial poles without adding to the bulkiness on the lines. I haven’t seen this done before and there is probably a good reason for it but naivety is the mother of invention, probably.
So far I have manufactured the tub from plywood, the plan is to manufacture the rest of the parts onto the plywood model making any alterations required until it all looks right, then to use it as a plug for a mold to form a fibreglass chassis. This chassis will be used on the road to see what breaks and what doesn’t work before finally committing the design to carbon fibre. The bamboo parts will be well tested and if they prove satisfactory will make it onto the final product, if they don’t they will be replaced by readily available carbon fibre tube but that is all months down the line.
This afternoon was the first opportunity to mount things in situ on the jig (offcut chipboard) and already I like how it looks although I have let to puzzle out how to mount the front boom and wishbones in the narrow space available, it looked wider in Sketchup than it is in reality.
The build costs so far …. edit… I was going to put the build costs down but I just scared myself totting it up. I will keep a record and decide if I dare report it as the project develops..
Getting There 