THE BLACK SHEEP
This is one of the most challenging projects, and has been ongoing for a year or so as my knowledge and experience has changed during the process, the design has changed during it but the concepts has remained the same, as the final design came about the changes became less and less, which for me was a sign that the design aspect of the project was coming to and end and fabrication should start
The power for the DH will of course be used for hill climbing and a substitute for peddling on the descent, once again allot of research has gone into the technology available the considerations has been of weight, torque, robustness.
Two motor ideas want to try-
Hub: the hub mounted idea is a 1500w hub built into the centre drive wheel, this would reduce the complexity of wiring and components needed to produce the drive, no chain, jack shaft, motor mounting with the frame would be needed giving space for bigger battery pack.
Advantage: less complex wiring depending on aggressiveness of the ride it can be more robust for ruff trails and smaller drop offs easier to maintain by the rider allowing them to buy if wanted products from other suppliers
Disadvantage: more weight at the rear of the bike, the less robustness on more aggressive trails.
Chain: this will be powered by an alien power converted RC motor to use hall sensors so a standard ebike controller can be used, depending on the power needed i.e. How much amperage will dictate what type of controller. The drive will be a centre wheel driven by a sprocket and chain, this design may or may not need a jack shaft.
Advantage: lighter in the rear of the bike adding most weight of the overall bike under the rider, freeing up space for centre shock, interchangeable allowing the rider to change the power of the motor easily with out to much cost, high level of performance, bigger drop offs can be done with more aggressive trails due to the centre mounting of critical drive components.
Disadvantages: more complexity in wiring that can lead to Niggli issues during a session if not properly maintained, a good knowledge or the willingness to learn electronics to get the best from the bike, less standard options in the market meaning a knowledge or research needs to be done to get the desired performance.. advanced users with a priori knowledge of off road biking.
Two choices of battery lipo and lithium
Lithium: this’s battery cones in the traditional form we recognise but obviously more power.. slitly larger than a standard AA battery these batteries are made into battery packs in a 36v 48v and higher , higher voltage is more power but depending distance designed will dictate how many battery’s and how they are soldered together in parallel and series
Advantages: easier to maintain, more buying options third part suppliers, good for DIY enthusiasts, safer of the two battery options, Less cost of the two options. Warranty in most packs purchased third party, lots of info in the web available.
Disadvantages: more weight of the two options, less power of the two options.
Lipo: generally Lipo are soldered in the same way but flatter and small packs, generally used in the RC world they are lighter and more powerfully.
Advantages: more power in a smaller pack, lighter.
Disadvantages: need to be charged using balanced charger or BMS, expensive, can be combustible during charge, and draw if not properly installed.
Depending on suppliers interested in the Mungrul project will determine on how much of the bike will be sold with standard components more over shelf available components, at present the core frame will be built in our workshop which I hope includes, CNC brackets, and all welding with functional swing arms, hopefully as more and more suppliers get interest the more will be available, but this core of the bike should always be available to make the concept of the Mungrul project work
Intended use: off road on dirt trails, free ride DH tracks
Unintended use: on the road or in built up areas, none public areas
– One of the most difficult areas of the DH bike is seating, I have some ideas but am very open to suggestions but keep in mind the need for minuverability of the rider..the rider will need to throw there weight left sand right for stability of the over all bike, hips and depending on the SCI or other disability stability will be around the hip area and lower back, the knees will use Velcro and the feet will have cleats and flip there feet in.. remember allot of upper stability will be gained from the handlebars
– Obviously the more skill set company’s that would like to get involved the more areas for extermination either the build can be done.. such as the frame using an aluminium with carbon composites for lightness and strength. Different components that we could test such as motors, brakes, tiers, rims, hand grips everything that is on a standard bike at the moment everything is limited to what we can afford
– Raw materials for prototyping would be needed along with the final build