Saturday, April 9, 2011

One week with a wooden cargo bicycle


Jeff & I (well mainly I) have now been riding model No.1 for a week and as we become more familiar with it we become aware of it's idiosyncrasies and it's shortcomings. This is enormously educational and has spurred a good deal of discussion about future iterations.
The bike performs excellently overall. It is light, responsive and comfortable. I am most proud of the handling, basically we nailed the geometry and all the hours I spent sweating the head angle/ fork offset/ trail equation were worth it. Todd at Clever Cycles rode it today and said; "It handles better than ninety per cent of cargo bikes out there and beats the pants of a Bullit". And that from someone who knows his cargo bikes. The response on the street has been overwhelmingly positive. Some people have scratched there heads as to the why until I tell them how much it weighs, then they have that 'aha' moment. Ed the Plumber from down the street suggested I take it to someone and have it made out of aluminum.........I guess the whole wood thing was lost on him. I have ridden the little man (68lbs) to and from school three times this week. I discovered I could carry him and keep up with the wife riding the Bakfeits with the electric assist pegged all the way. Not bad considering it has one gear. It's strong too which is good because Jeff has seen fit to jump it of curbs on his late night rambles with Essie. "Haven't bunny hopped it up a curb yet", he says encouragingly at which point I cover my ears and shout lalalalalala!".
On the down side there is an odd sideways judder that occurs when hitting a bump. The whole forward end shimmers like a tuning fork but to the right.....weird. I attribute this to sloppy alignment of the frame. I was also experiencing some wheel wobble particularly when standing on the pedals and negotiating a curve (like climbing up to the Hawthorne bridge from the esplanade). This was largely solved by letting some air out of the front tire as I had over inflated it a tad. From a design perspective a total flat bed cargo area is a pain. You can't just throw something on there and go with out it sliding around and threatening to fall of. Next version will have a nice generous lip with convenient hand holds for bungees and, well, hands. Not including a slot for a d-lock was another forehead slapping 'duh' moment. That too has been added to the list of really obvious things to do next time. Also under discussion are the cut outs on the side panels. My feeling is they add nothing aesthetically and certainly don't save a lot of weight. They either need to go or get more sexy. From a production standpoint cutting all those holes ate up time tool pathing & cutting on the CNC.
What is encouraging is that all these shortcomings are understandable and solvable and that future versions can only get better. For know we take a deep breath and prepare to move forward.

Oh, and also, I swapped out the gas pipe BMX bars for a sweet blue anodized pair in aluminum. Probably shed two pounds right there..........

2 comments:

  1. Hi Michael,
    That bike could be a great canvas for all kinds of art, with all the flat space.
    What kind of steering linkage is going on there? Hard to see in the picture.
    Integrating a shallow bathtub shape in the cargo bed may fix some of the handling issues you mention, with the extra reinforcement. And make it more load friendly. What HA and fork offset did you use?
    Thanks for posting. May pull out the table saw for my next bike project.

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  2. Drew,

    The steering is comprised of a steel t-section connecting the two head tubes directly. Crude but effective. Right now we are working on replacing that with a cable system. You are right on the cargo bed. Next version will have taller sides and we might also try glassing the cargo bed to see if we gain some rigidity.

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