Paul Brodie and The Whippet #8

Paul Brodie and The Whippet #8

We’re approaching the last episode in Paul Brodie’s instructional series as he takes us through the steps involved in rebuilding one of the most complicated classic bicycles you’ve seen. By the time you read this, the North American Handmade Bicycle Show at the Sacramento Convention Center will be a roaring throng of boutique bicycle lovers, and in the middle of it all will be Paul’s re-created 1888 full-suspension Whippet.

“I have quite a few photos of the Whippet sitting in the Ottawa Museum of Science and Technology. It’s under plastic, sitting up in the mezzanine — not on display. I do not, however, have one photo that shows an entire crank arm. So, here is the lower section, held to the BB axle with a tapered cotter pin. The top of the crank arm featured an adjustable slot for different crank lengths. Isn’t that perfect for a cyclist that has one leg longer than the other?”:

Paul Brodie and The Whippet #8

“The starting point was a bar of 954 bronze that cost me $100 several years ago. 954 bronze has a higher tensile strength than 4130; perfect for strong crank arms”:

Paul Brodie and The Whippet #8

“There was a bit of extra material, so that got milled off”:

Paul Brodie and The Whippet #8

“Machinist blue for layout, as usual. Critical holes have been drilled and bored. Now it’s just a matter of getting the shape right”:

Paul Brodie and The Whippet #8

“A facemill was used to make a very slight taper from top to bottom”:

Paul Brodie and The Whippet #8

“The sides were still parallel, so it was easy to hold the arm in the mill vise and slot for the pedals”:

Paul Brodie and The Whippet #8

“A carbide insert in a Boring Head is used to mill a flat for the washer and pedal nut to tighten against”:

Paul Brodie and The Whippet #8

“See the arc scribed in the lower machinist blue? I need to machine a radius very close to that line”:

Paul Brodie and The Whippet #8

“A large endmill is used to do that. See how one crank arm is held in each side of the vise? This keeps the vise jaw even and square”:

Paul Brodie and The Whippet #8

“Now the sides are milled at a slight angle. See how the crank end is C-clamped to a right angle plate? This stops vibration and tool ‘chatter'”:

Paul Brodie and The Whippet #8

“Crank arms are taking shape, but I think the top and bottom surfaces would be better with a slight radius…”:

Paul Brodie and The Whippet #8

“This is my porting tool. You can see the electric motor in the background, and the hand grinder up close with a carbide burr. A cable connects the two, and a foot pedal (not shown) controls the speed. The speed isn’t that high. This great tool is now being used to radius the top and bottom”:

Paul Brodie and The Whippet #8

“A hand file is used in the corners for blending”:

Paul Brodie and The Whippet #8

“Back into the rotary table for machining the radius around the bottom bracket axle. I don’t know if Whippets really had bronze crank arms, but why not? The late 1800’s were a time of great bicycle (and tricycle) experimentation, and bronze was used in other cycle parts, such as hubs. I enjoyed making these crank arms, and they polished up quite well”:

Paul Brodie and The Whippet #8

“Done!”:

Paul Brodie and The Whippet #8

Paul teaches Framebuilding 101 at the University of the Fraser Valley. For more information on the course, where you can learn how to build a steel framed bicycle using Paul’s original jigs that have built over 4000 frames, visit the UFV website.

Previously:
Paul Brodie and The Whippet #1
Paul Brodie and The Whippet #2
Paul Brodie and The Whippet #3
Paul Brodie and The Whippet #4
Paul Brodie and The Whippet #5
Paul Brodie and The Whippet #6
Paul Brodie and The Whippet #7

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