The Breeze recumbent cargo bike frame is rolling!

 

The Breeze is now a rolling chassis.  Although it still needs a front trunk with a solar panel lid, a retractable solar canopy, a deflector in front of the pedals, and oversize rear panniers built, I'm finally able to ride it around (before snow!)  I started building this single track semi recumbent electric cargo bike during the Covid quarantine while I was ruminating on the role of bikes (and walking) in a car culture.  As a result there are several unusual details which I can write more about this winter, but for now I thought I should put up a few photos.  (Click on the pictures to enlarge them.)

Single track recumbents are steered more by your hips than the handlebars so some people may have a difficult time riding one, (those with back or balance problems), however I've used a RANS Stratus for a few years and greatly enjoy it, so I wanted to build a heavy duty version that can haul groceries better.  I didn't want to have to push this bike home while I'm commissioning it, so I've ridden it for 2.5 miles just around the yard so far.  It's OK on grass, even with the motor shut off.  It does feel a little unusual when I get on it and it sinks 1/2 inch to sag position, but there hasn't been any pogoing or wallowing.  I have a steep, long, gravel driveway and it tracks very comfortably down to 2 or 3 mph going uphill or down so I think most of the dimensions are correct, but of course now that I've built it I can see a dozen little details that I'd do different next time.  The one odd behavior I don't fully understand is when I try to U-turn within a lane's width (10 to 12 feet wide), I end up leaning way over (40 degrees) at which point the front wheel turns sideways, the bike comes to a stop, and I do a slow roll onto the side.  (I need to U-turn to the left to spare the derailleurs!)  I eventually learned how to U-turn my bakfiets within one lane so this geometry/ergonometric speculation is mostly in case I build another frame.

Technically this is a Class 1 ebike: it has a Bafang BBSHD motor which I've programmed down to 720 watts (15 amps at 48 volts) and 20 mph to make it legal for both Vermont and New Hampshire, and I didn't install the throttle.  It has 26"x1.5" tires for mud season, with 8 speeds for the motor plus 3 more for the rider (two chain loops as 1x3x8).  There are 2 batteries totaling 1.68 kWh for longer trips, (plus I'd like to try heated grips or seat cushion).

The horizontal display mimics a car dashboard.  On the right is a standard Shimano SL-R440 8 speed shifter for the rear cassette.  I ended up using an upside down Shimano Deore 6 speed thumb shifter (hidden under the Bafang keypad on the left) for the motor mounted high/mid/low range cassette because the cable pull was the best match after I had to shim the sprockets to avoid chain rub.  The front trunk bin will mount on the horizontal tube using the welded on m8 nuts, and the handlebars should be just below the height of the flexible solar panel lid to give wind protection for my hands.  Although the handlebars are minimum width, the bell fit ergonomically in front of the display.  The curvature of the handlebars are a natural angle for this riding position, (Mike Burrows' Soup Dragon used a similar arc).  To reduce the handlebar interference with my legs there is a slight step up ratio (1.2:1) on the steering, but I need to rack up some mileage to see if this is a good idea or not.

I included a bottom bracket at the front of the rear rack as a pivot for the retractable solar panel canopy, and when the top is down a 60 watt panel should extend just beyond the rack to the end of the bike.  The head and tail lights required a solid state relay circuit because the BBSHD supply was not powerful enough, and I tested 11 ebike headlights to find one with good focus and cutoff like a car headlight - I'll try to post a blog with this data during the winter.

Even though the bikes I build are just for getting myself around, I couldn't resist painting my Scarlet Runner Bikes logo on the head tube and down tube to try to trick people into thinking this one is from a factory.  (Also I think the Scarlet red looks good on the Chicory blue.)  This winter I'll try to post about more design considerations (there's a lot to say about the suspension besides the headlights), but our legislature will be coming into session soon and I expect to spend some time advocating for better bike/ped infrastructure on Route 5.  (Thank you all you other advocates who are helping bring about a better human scale transportation system.)  Now to get in some test miles before the salt, dirty slush, and ice will make it difficult to finish up the bodywork.

The Breeze frame is painted, plus a little bike advocacy

The Breeze single track semi recumbent frame (click to enlarge)

Last month I finally finished welding all of the small mounting tabs on The Breeze frame and sprayed a coat of chicory blue paint on it.  All of the small hardware still needs to fitted and this will take a while because I've done some unusual things (like cutting a freehub in half and mounting it on the motor's square taper crank).  But it's kind of neat and the rear suspension is actually supple, so I thought I'd post a picture of it.

I started this frame during Covid, but ended up building it as a side project because bike advocacy work became more important.  I've been using my ebikes as serious transportation since 2010, and next month will be 8 years without a car.  I live 5.5 miles away from the center of my small town in a rural area, and roads have become important.

In his book "One Less Car", Zach Furness quotes Sara Stout as saying:

"At first bicycling is utilitarian, it's just how you choose to get around... but it becomes political really quickly because it's hard to get around.  There are difficulties at every turn, and there seem to be injustices at every turn."

Being a builder geek I was a bit slower to understand this problem than Sara, but after 5 to  6 years it occurred to me that our roads have some major design flaws for anyone outside of a car, and this was scaring many people away from riding everyday like I was doing.  I started locally by asking my town manager and select board to include bicycles and pedestrians in their plans, but it grew and now I'm part of several transportation organizations.  One of my biggest supporters has been my state Sierra Club chapter - they have a Clean Transportation for All (bike/pedestrian/transit/EV) campaign.  I've been given the opportunity to testify 3 times before my state legislature for better support for bicycling and walking, and now I'm advocating to make US Route 5 in Vermont (along the Connecticut river from Massachusetts to Canada) safer for bicyclists and pedestrians.  Besides local river valley biking, this route would fill in a missing north-south Rail Trail system gap between the Farmington Canal trail starting on Long Island Sound up to La Route Verte in Quebec.  You don't have to be as involved or technical as I've gotten, it's just important to show up because otherwise all that the transportation people hear are car drivers loudly demanding pothole repair and more parking.  I actually think pretty highly of the people I've met at my state DOT, but all these agencies need to hear there is a demand for bike/ped facilities to justify taking time and money away from cars.  Now that I've stepped back from cars I can better see the insanity of all the externalized costs and effects of our car based transportation system and feel like speaking up, but please show up even if you just watch, or sign a petition, quieter voices need to be heard too.

Back before Covid I realized that our transportation system was not going to change quickly enough for me.  Since I had to travel 11 miles one way for groceries, 6 miles another way for the Post Office or bank, or 16 miles another direction for errands, I needed a bike that was more car-like to fit in with the existing road network.  My bike had to compensate for 1950's planning that expected people to drive a fast car everywhere. 

There were 3 main design inspirations for this frame.  To start, a semi recumbent would be similar to a car and I have a RANS Stratus that I've liked.  However the Stratus twists too much when there is a large load of groceries on the rear rack, and the fiberglass seat without any rear suspension can be a rough ride.   I used pedal drop and reach dimensions from it combined with dimensions from an EZ Racer and a mock up.  Second, my last few cars were Saab 900's (the early version), and aside from inaccessible service components they had a design philosophy with their planes I liked.  I used the 18 inch seat height, the 60 degree steering wheel angle (in line with shoulder joints) and other packaging and ergonometric details.  Third, I've loved Porsche cars since grade school in the 1960s, so the Breeze was getting a mid motor.

To these basic parameters, I added 26 inch wheels (for dirt roads) with rear suspension, a front storage compartment with a solar panel cover to keep rain off of me, dual batteries for longer distance, and a retractable solar canopy with a drop down windshield.  It took quite a bit of drawing to get it all to fit together, but we were quarantined for Covid anyhow.  The bodywork is going to take some time, but I expect to be riding the bare frame this fall to find out if it is going to work or not.  As I put it together I'll post more pictures of the details.

The Breeze, the Stratus frame (S1E2)

I'm only moderately familiar with recumbent design, and my first step was to figure out what the Stratus was supposed to be like originally, before years of different owners had worked on it.  I didn't find any original documentation from 1985, but there was a 1992 review in the Recumbent Cyclist News archives (https://rcnpdf.com/ , Vol 6 No 12).   Amazingly my bike was pretty much whole, with the original Shimano 600 group set.  I was going to have to change some of that out because I didn't think a 35 year old freewheel would be reliable enough for my use, but I'd be changing the front chainring anyway with the addition of a motor.  There was also no way I'd use the shifter and brake on the joystick. But overall the frame was straight, and mainly needed a new coat of paint.  It had a sticker on it from Dana Point Cycle and Sport, and I imagined the original owner cruising up and down the California beach front listening to "Hey now, Hey now, Don't Dream it's Over".

The RANS Stratus A as received

Out of the many bikes with a lower seat height, I was lucky to receive this Stratus.  This model and the Easy Racer Tour Easy (https://easyracers.com/toureasy.html) appear to be 2 classic bikes that are so popular that one blog writer claimed they are the bikes that have crossed the US the most times.  It's a very good place to start from.

An Easy Racer Tour Easy with an early electric motor drive kit added under the seat.

Photo credit: I don't know the original source, I found this photo on recumbentbike.com back in 2014, and that site now appears to be dead.  I've seen this picture on a few other sites since then.

The Stratus has a bottom bracket height of 14 inches off the ground and a seat height of 21 inches, while the Tour Easy has a slightly more upright position at 13" BB and 22" seat.  I had been planning on a seat height of 18" for The Breeze frame to match many household chairs I have and also the seat height in my old Saab 900, but I found while riding the Stratus I liked a 1" pad, which gave me a 22" seat height that matches the Tour Easy.  However the Stratus BB height is better at 14", as the heel of my shoe was often less than an inch from the ground.

The frame after welding the rear dropout and painting, with the new wheels

(It's mounted in an old exercise stand to prop it up.)

Evaluating the frame design while cleaning it up was lot of fun!  There were a few things I wouldn't have done, such as the plastic cap closure for the seat tube, and the termination of the stays on the rear dropouts (which I'll say more about in the drivetrain post).  Also I was wondering how the BB to seat to rear dropout triangle would handle the torque of a motor.  Otherwise the frame was thought provoking!

A 59 degree head angle with a centering spring added to counteract flop

The 59 degree head angle confirmed something I've learned since I wrote my blog posts about steering geometry back in 2014- the basic function of the head angle is to put the handlebars comfortably within the reach of the rider, and handling is secondary.  Here's an example that demonstrates the important aspect is trail, not head angle:

Tony Foale rides his modified BMW with a 15 degree rake (motorcycle terminology, or 75 degree head angle in bicycle terminology).  Tony modified his motorcyle for testing with rake angles of 15 and 0 degrees, which under some conditions performed better than the stock 27 degree angle which could oscillate. 

Credit: Motorcycle Chassis Design: the theory and practice, Tony Foale and Vic Willoughby, 1984, Osprey Publishing Ltd, page 62

The Stratus head bearings were notchy, and I found a current version that looked the same but now had seals!  The front wheel wasn't original, it had nuts and 90 mm Over Locknut Dimension (OLD) while the fork had 100 mm spacing.  I dug out an old Shimano 100 mm quick release front hub that looked period correct and built a new wheel using an aero shape rim.  A major side effect of the 59 degree head angle is a tremendous amount of annoying wheel flop, and after a couple of weeks of having the front fork turn sideways whenever I let go of the handlebars, I made a centering spring.  It's just 4 inches cut off of an old spring for a wood screen door (the kind that always slammed shut with a bang), and is attached to the fork with a little ell bracket on the brake caliper bolt, and onto the frame by hooking it on to a hose clamp.  I still have to figure out a front fender though, because RANS cut it a little too tight with less than 1/8 inch between the tire and the fork crown.

While I did remove the central joystick, I wanted to keep the front fairing + storage cubby.  I added bar extensions to the hoop handlebars instead of the usual update of  "ape hanger" bars.  This bike is steered by leaning, not by turning the handlebars, and it took me a while to learn to steer with my seat.  I had to not lean on the backrest for about 20 miles before it started to become more natural.  There's a small amount of tiller effect during slow, sharp corners, but at speed it's not noticeable at all.  The handlebars aren't very solid and mostly just a place to put your hands, but the fairing does block the wind, and the cubby is really handy! 

The cockpit with a pair of Dia-Compe SS-4 two finger brake levers and a Shimano Mega9 shifter sandwiched in between them.  The BBS02 keypad is on the left handlebar extenion, and it's LCD display is on a custom bracket that mounts to the fairing in front of it.  (The handlebar extensions are cut off in this photo.)  All cables and wires fit under the bar tape for a comfortable grip, although it is a pretty close fit.   The brake switches are the inline cable type and hidden inside the fairing.

I've adjusted the hoop so that my knees have just an inch of clearance to the underside, and realized that while a fixed solar panel could be mounted over my knees on a bike frame that has steering with a remote linkage, there wouldn't be much space for a front trunk underneath it.  Also a solar panel over my head would be much taller than I had planned, so the next step is to reconsider the seat height again.

The rear wheel is also new.  I had planned on upgrading the antique freewheel hub to a freehub to better handle the motor torque, but I found a complete wheel that I was able to modify, so I simply replaced the whole thing.  I'll cover this part a bit more in the next post about the drivetrain.

The seat cover had shrunk and I had to make a new one.  Also the original kickstand simply spun around on the chainstay, so I took a standard Greenfield kickstand and lengthened it by epoxying on a 4 inch piece of a salvaged seat stay that I had hammered into a profile that slipped on the leg nicely.  (This took three tries:  on the first try I hammered too hard and snapped the leg off, the second time I tried using a torch to soften the tube and melted the aluminum kickstand.  The third time I applied a lot more patience.  It's good that these kickstands are common and inexpensive.)

The extended Greenfield kickstand

The chainstays are very slender and could be bent, so I made top and bottom mounting plates out of 1/2" CDX plywood with grooves routered in them that cupped the tubes to spread out the force of the kickstand   Then after mounting the kickstand I scribed the end of the leg to the correct angle and welded on a circular foot.  I had originally planned to combine the kickstand mount with a pair of chain idler pulleys, but the pulleys weren't necessary.  I'll write more about this in the drivetrain post.

The almost finished Stratus project, (it still needs a front fender and another layer of foam on the seat)

I finished the bike in September and rode it for a couple hundred miles before snow started and then I parked it to keep the road salt off of it.  It's very fast- easily able to keep up with cars in 25 mph zones, and under most situations it's very comfortable.  It's definitely in it's element on a paved road, but it's been fine on all the dirt roads here except for the worst ones where the town has dumped a lot of 3 inch stone.  For The Breeze I'll probably go one size wider in tire width, from 1 1/4" (32 mm) to 1 1/2" because of the stone, but I don't wish to go wider because I also need to cover distance quickly.  I've found it hard to choose between cruising along on this bike or the more upright posture of my converted Marin eMTB and I split my time half and half between the two.

For the next post I'll take a closer look at the drivetrain.