Saturday, December 25, 2021

The Breeze, or learning how to travel (S1E1)

Advertisement for a Danish Sofa-Cycle, circa 1930's, credit: unknown

 I've wanted to build a sofa cycle for 4 or 5 years now.  The main reason was comfort- to be sitting looking fowards instead of down, and to have my feet flat on the ground when stopped.  There was also a hope for better efficiency from a smaller aerodynamic profile.

But other bikes kept sidetracking me.  I've now put motors in 24 bikes and have 4 more lined up, (the motors I've used are 3-MAC geared hub, 1-MXUS DD hub, 2-Leaf DD hub, 2-generic 250W DD hub, 14-BBS02 BB, 1-BBSHD BB, and 5-TSDZ2 BB motors).  Plus there have been a few extra projects such as the DIY ebike workshops, our Upper Valley ebike library, and rebuilding the battery pack in a Twike (which had 1568 cells to weld together!).  It seemed like I'd never get to building another frame.

I'd started in the direction of a lower seat with the Oma bike (see links to blog posts on the right).  But the Oma bike had 3 significant problems:
-I'd used too small tubing which flexed a lot and I constantly had to pay attention to balancing
-the motor pulled the rear wheel out of the dropouts and needed repairs
-it's very long
So I ended up not using it very much, and wanted to try building again.

There were several times that I almost bought a RANS Crank Forward bike ( ) just to move things along.   But then I'd see something like this:

Bram Moens rides his M5,
Credits: photo-Frans Lemmens, book-The Recumbent Bicycle, Gunnar Fehlau, 2000, Out Your Backdoor Press

Then I'd think I could do better than a crank forward.  What if Bram had a solar panel over his head, another panel over his knees, and a slightly stretched frame with large cargo bins centered over the rear wheel?  I'd have a vehicle that never needed charging and had some weather protection.  So over the last few years, I've figured most of the design out.  A monotube frame with a strong arch over the rear wheel for the cargo bins.  A motor under the seat, and a new solar setup.  I've collected most of the parts- the tubing, wheels, group set and other hardware, a BBSHD motor, rear shock and bearings, plus few extra parts for experimenting with a Hossack front end.  It's taken long enough that I've even got a theme song- 

Call me the Breeze, J.J. Cale, Cain's Ballroom, Tulsa, (2004)

But other projects keep popping up.  They've been good experience, for example I can now build a wheel in an hour or two instead of a whole day.  And I've put in some serious time on bicycle advocacy, learning our transportation system, and speaking up for non-car users here in Vermont.  Still, my frame is going to have to wait for a second Series of blog posts.  First I have a detour that qualifies as The Breeze, Series 1.

Last summer there were again too many projects for me to make the space I needed to work on the last details of building my frame.  At the same time, my friend Bill decided to clean out some of his bikes, and one of them was a RANS Stratus recumbent.  My design+build is half calculation and half intuitive- my cells absorb the situation, and then my hands unconsciously build.  The calculations are mainly a double check that it's feasible.  I had the idea that it would be helpful to experience a bike with a lower seat before I built my frame.  I also had a stack of 18650 cells left over from other projects. So Bill and I swapped parts.

1985 RANS Stratus A, with BBS02 motor

This turned out to be a pretty nice and quite fast bike, and very suitable as a local car replacement.  The motor takes care of the usual recumbent hill climbing problem.  It's able to comfortably carry a medium load of groceries (50 pounds).  I'm continuing to learn how to travel.  The bike needed a bit of work, and I'll run through the process in the next few posts of this first series of The Breeze.