Matt is from Perth in Australia, and he has built this custom cruiser frame from the ground up. I am seeing more custom frames being built these days, but this one in particular has had a tremendous amount of time and effort put into some really fantastic details that I’m sure our readers will appreciate.
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The Basman Frame
Mit freundlichen Grüßen / Best Regards…”
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The Beginning…
A few years ago, Matt Parks decided he wanted to build an electric Basman bicycle from scratch, so he could make the tank area large enough to fit a certain battery that he wanted to use. Here is the original tracing, and also the start of a custom frame that he made.
“…I read about a few people here on ES using Delta CAD, so I down-loaded the trial version of DC and played around with it for about 3 hours. I highly recommend it for it’s ease of use. I designed a right and left drop out, both with 10mm wide horizontal axle slots, and the left has two 6mm wide disc brake mounting slots. I had them laser-cut in 8mm thick steel…”
The 10T geared MAC hubmotor in a 26-inch wheel using 48V would provide a top-speed of approximately 28-MPH (45 km/h), and as a result has proven to be a very popular choice for commuters in the US. The 8T version shown here would run at slightly higher RPM’s.
The wheels shown here are the 24-inch X 80mm wide model. The forks are Fox 40 units, and the lower shells were removed and powder-coated to match the frame.
The battery is a very safe and reliable LiFePO4 chemistry using the flat and square foil cells from a company called A123. This pack has 16 cells in series (16S). The nominal rating for 16 LiFePO4 cells is 48V, and when fully-charged to 3.65V per cell, the pack would start out with 58.4V. This pack has 20-Ah of range.
Since the max voltage doesn’t exceed 60V, the 12-FET controller can use the efficient and cool-running 3077 FET’s, and that means you can get a lot of power from a fairly small controller.
The tires are the Maxxis Hookworm, 24 X 2.5-inches wide. However, when combined in a rim that is wider than the designers intended, the tire spreads out even wider, and the sidewall becomes shorter. Some builders have done this to achieve a certain style, but Matt likes the way his ebike corners with the tread being this wide and more rounded.
The kickstand almost looks like it was made from scratch, too. Matt actually found this on EBAY, from seller ozdirectseller.
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Music, and a Cycle Analyst as a Dashboard
Matt wanted to have music while riding, and chose a bluetooth outdoor speaker that runs on 12V, and was designed for motorcycles. This allows the speakers to draw their music signal from an MP3 player or a smart-phone that is kept in your pocket.
Here, a custom mounting bracket was made from some aluminum angle, and will attach to the handlebar stem clamp.
Another custom bracket set attached the Cycle Analyst V3 from Grin Technologies to the bottom of the speaker housing.
This is a very sleek and elegant solution to providing music, and also a readout for the electrical system.
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The Tank
Matt had decided he wanted the look of a carbon fiber “fuel tank” to cover the battery, controller, and the DC/DC converter (48V-to-12V). He was advised to make a dummy tank in the exact size and shape desired, then make a mold from that, and then finally use gel-coat and carbon fiber cloth to form the final shape inside the mold.
Most builders might have used thin plywood to make the supports for the dummy tank, but Matt had a lot of clear lexan laying about, and used that simply because it was convenient.
One of the properties of Lexan that makes it useful to custom builders is that…when heated, it can easily be bent into a curved shape. Here Matt used thin strips to fill out the rough shape.
Matt found it convenient to cover the dummy tank with tape at this point as a base for plaster.
After applying some quick-dry plaster to firm up the shape, Matt used a (brown) clay that would be easy to shape and smooth over. In the pic above, the left side is still in the brown shaping clay, and the right side of the tank has been sanded smooth and primered to help show imperfections, to allow additional smoothing.
Here are the two molds that were made off of the dummy tank. They were then coated with a “release agent” to prevent the carbon fiber cloth and epoxy from sticking. Once the cloth and epoxy were carefully placed in the molds, and then hardened…the finished pieces popped out.
This is the first time Matt had ever worked with carbon fiber, and I think he did a great job!
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Powder Coating and Final Assembly
“…my powder coater doesn’t have a number for this blue. He said it’s just called candy blue. He first puts a metallic silver coat on, and then the candy blue on top. The sparkly silver looks great under the blue, and you really need to see it in person and in sun light…”
Powder coating provides a much tougher finish compared to paint. And getting the frame back from the powder-coaters is an exciting day, because…that means final assembly is just around the corner!
A beautiful sight! The motor might not look very large, but it is a MAC geared hubmotor, and the internal gear-set allows the motor to spin 5 times faster than the wheel. This increases the motors torque and efficiency.
By breaking down the motor and forks to their individual parts, Matt was able to have their external shells powder coated to match the frame. We don’t see this level of effort very often, but the results speak for themselves.
After riding for a while, Matt decided the leather Brookes saddle was not as comfortable as he would like for this style of riding posture, so he swapped-in a wide cruiser saddle.
Here, he covered the motor phase cable with stainless steel braided sleeves. The red ON/OFF switch has a handle that can be removed when it’s in the OFF position.
The tail-light is an awesome styling touch, and the hydraulic Hope disc brakes are more than adequate.
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LED Lights
Matt occasionally rides at night, and wanted to add some 12V LED lights to add a final touch to the design.
This shot shows the four illuminated switches for the DC/DC converter, controller on/off, tail light, and blue LED strip.
The blue LED strip that he added is very eye-catching , and also makes this bike much more visible to cars driving at night. If you want to read more details about this build, here is the endless-sphere.com chat forum discussion.
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If you liked this build, you might also like these:
http://www.electricbike.com/marks-cromotor-phatrod/
http://www.electricbike.com/patient-zero-chopper/
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Written by Ron/spinningmagnets, December 2015
