Denver is, as we speak, rapidly filling up with custom frame builders, bloggers, industry types and beautiful bike lovers, drawn together by the 2013 North American Handmade Bicycle Show. One exhibit that is sure to delight some and frighten others, is an amazing electric bike: Paul Brodie‘s eBee. This week, Paul has been walking us through each stage in the eBee’s construction, a real testament to his skill and engineering ability. Here’s Part 3:
“I needed to build a new stem cap to hold the Cycle Analyst computer and the fairing. I took two pieces of aluminum, held them together in the mill vise, and bored a 31.8mm hole. When I opened the vise, I had 2 pieces that looked like this ^.
“In the front is the original cap, and above is the new one, half done. Quite a lot of metal got removed:
“Finished, and waiting for a coat of red paint:
“I needed a head tube badge, so why not start with a solid chunk of aluminum?
“The 6061 aluminum is bored to the same size as the head tube OD. The decal was photocopied and enlarged to 160%, then traced onto the tube:
“Quite a bit was done in the mill vise with a 1/4” end mill, followed by some hand filing and sanding. It would get anodized pewter:
“A lot of aluminum scraps got converted into eBee parts. A total of forty-six machined parts were sent out for anodizing. This chunk of aluminum got used for the Cycle Analyst / fairing mount:
“Here, the mount is slowly taking shape in the mill vise:
“The finished part:
“These are the holders for the two Rohloff cables, under the left seat stay. The radius on each end was done on the rotary table:
“Figuring out the shape for the fairing. The shape is developed using aluminum welding rods and a glue gun:
“View from behind.
“The welding wires were covered with masking tape, and fiberglas matt covered that, followed by bondo. This was sanded smooth to the desired shape, then primed, sanded, painted, polished, and finally waxed 5 times. This is the “plug”:
“Here, gelcoat has been sprayed over the male plug. This is the start of the female “mold”. Over this many layers of fiberglas matt will be laid… this forms a very strong mold:
“This turned into a disaster when the plug refused to separate from the mold. It had to be chipped out, and the bondo softened up with successive coats of paint stripper. It was winter here, so a lot of the painting, stripping, bondoing, fiberglassing, etc. happened inside. I’m sure my shop was not the healthiest place to be. When the plug was finally out, I had a damaged mold, so that had to be repaired before I could lay up the little fairing:
“When eBee was mocked up, I took circles of masking tape, and placed them on the side plates to see where holes might look good. The side plate was then clamped on the mill table, and the center of each circle was marked with a +. After the center of each hole was located with the mill spindle, I used the digital readout to save time when going from hole to hole. The numbers in red felt pen are the X/Y co-ordinates:
“This is the final version of both plates, ready to be sent out for anodizing. The color will be pewter:
“Everybody has a Chris King headset, it seems. I like Chris King; I think he’s a great guy. However, I had some aluminum, and believe it or not, some spare time, so I decided to make my own. It will be anodized black:
Today, Paul teaches Framebuilding 101 at Canada’s University of the Fraser Valley. He started Brodie Research and Technology in 1986 before going on to build some of the most highly sought after frames in western Canada and the US. The last installment in Paul’s eBee tutorial is Part 4: keep an eye out for it and if you’re lucky enough to be going to NAHBS, see it in person at the
University of the Fraser Valley’s Booth #736.