(TrikeE)
Last year ('05) a bicycling couple, who are friends of mine, and I traded bikes. She was recovering from recent back surgery and needed a soft, cushy ride. I wanted a 3 wheeler for it's stability. He had bought an EZ3-USX for his aging Dad but it never got used so after a year his Mom asked him to bring it back to the Cities.
Of my two BikeE's, the street model had rear air suspension and rode like a Mercedes Benz.
So we swapped
I'm not a fast rider, I lallygag along, stopping to take pictures, pick a flower, visit, maybe dive a dumpster or two, etc. For a car, I drive diesels and have wanted to make the modifications to burn used restaurant cooking oil as fuel but. . . . . .but I hardly burn 5 gallons of fuel a week and that's mostly short trips that I won't take the time to use the bike for, even if the weather is nice. If I could double the trike's speed I might use it for more of these short trips, so 'Electric Assist' became interesting and the cooking oil idea went on a back burner.
The guys at Edina Bike and Sport helped me get a motor and drive from Jim Black that uses bicycle size chain, and drives the rear wheel's gear cluster through a sprag (one-way) clutch. The sprag clutch allows you to pedal the bike without turning the motor, or motor the bike without pedaling, as if 'coasting'. Elegant! The motor also has a 10:1 planetary reduction drive going into the Sprag. I used 3/4" x 1/8" aluminum angle iron and some very nice hose clamps from German Auto Works Service to mount the motor and to support the additional shiftless derailer that tensions the front chain for it's triple gear crank set.
One of the things that makes this 'Mid Drive' work is the extremely long chain line you typically find on recumbent bikes. The most accommodating location in my TrikeE's frame for the motor happened to be about midway along the chain line.
The motor's side to side positioning and shaft alignment was easily adjusted with shim washers.
The Trike is easily stood upright for storage and allows another view of the rear chain alignment. You also get a better view of the hose clamp mounting methods. Thick 3M transparent tape was wrapped around the trike's painted tubes where chafing might occur.
Because of the 'under-seat steering' the hand grips and controls need to be arranged to accommodate a 'paper covers rock' grip rather than the traditional.
The motor's thumb throttle fits comfortably to the hand when positioned thus:
First Rides
On my first couple rides (not pedal assist) it seemed to go like hell for about 6 miles and then started 2 second duty cycles (2 seconds on, 2 seconds off, etc). In 1st gear the motor would spin up to full rpm and I think it's going to be a great hill climber. The unofficial steepest paved hill in the area runs up from Ft Snelling State Park, on the Mississippi river bottoms, up to the old fort itself which is situated on a high bluff overlooking the delta of the Mississippi river and the Minnesota river's convergence. Climbing this hill (red) will be 'THE' test.
To continue. . . . 2nd gear almost reached max motor rpm, third a little less and on up through 8th at which point the motor seemed to be turning under 50% of free shaft speed. The interesting thing was that even though the motor progressively slowed in each higher gear the trikes speed kept increasing. At max speed in 8th gear, if I shifted down to 7th, the motor speed did increase but road speed dropped some. Here is a graph of various operating characteristics including Torque (green) that may simplify and explain this phenomenon.
It appears that if this trike is to replace my car for short trips I'm going to have to increase the battery capacity. There are several different types of lead/acid batteries. Here is a -site- or -two- for more explanation on types, performance, etc. Because of my background in the auto trades I'm most attracted to the flood batteries (wet type) but should there be an upset it could get messy environmentally. You'd think wheel chair and handicap scooter batteries would be acceptable and I think they are flood type. Back when desert racing was popular they would use 'check ball' aircraft type cell caps to prevent acid leakage in a rollover and those guys did tend to roll their little dune buggies over from time to time, E-ha!.
The battery search and research will go on. I installed and calibrated a speedometer a couple days ago and quickly found out why the batteries don't last as far as I expected. This picture was taken at 22.5 MPH without pedal assist.
I've since tried pedal assist at 15 mph and didn't get much better mileage. I was out longer and visited a while at half time so maybe the batteries cooled off some (35ºf). The chemical reaction that stores the energy is greatly reduced at lower temps.
-Battery update-
When a wet lead acid battery (flood type) sits unused, it self-discharges about 5% per month and after 6 mo becomes sufficiently discharged to start forming deposits on the plates. Most responsible retailers rotate their stock through a distributer or warehouse who will test these returns and recondition the least effected units with a shock and trickle charging technique followed by a final load test before they offer the unit as 'reconditioned' at a discounted price.
During my battery research I met David and Gil at Northern Battery's warehouse #7 here in the Twin Cities and they were very helpful and enlightening. Dave Krafft and I visited them and found a couple 105 amp, Group 31, deep cycle batteries, reconditioned, that I am using in a kiddie trailer for long hauls behind the TrikeE.
I bought a pair of cheapo jumper cables (10 awg) at an auto parts store for about the price of the wire. I cut one pair of ends off at 2'. On the long section I crimped new terminals to plug into the trikes motor and then clamp on to the battery terminals. I put ring terminals on the 2' cables and use them to patch the two batteries together either in series for the 24v motor or in parallel to charge at 12v. All flood batteries prefer to remain nearly fully charged, however when new it's best to season them with several deep discharge/recharge cycles. Without the benefit of 'seasoning' I'm easily getting 50 mile range from these 105 amp units.
I have discovered a modern battery charger from one of the oldest and most respected makers, Schumacher; it tests the battery to be charged and manages the charging protocols to suit conditions. In reading the owners manual I found this item:
My charger came from Fleet Farm , locally, and was about 1/3 cheaper than advertised on-line.
(Battery charger update)
The electronics inside that new battery charger didn't like all the vibration and banging around it got riding around in the trailer and after a few weeks quit working in a puff of smoke. Fleet Farm was very nice about taking it back and doesn't appear to stock that model any more.
The Hill Test
Last weekend Joe McC. and I rode out to Ft Snelling and climbed the hill. He rides a Dragonflier Trike without the 3 speed 'mid-drive' and stopped to rest about 3/4 of the way up. I did NOT motor up the hill with the TrikeE, but I did make it all the way with pedal assist. Once I got to the top I took the trailer off and tried it again with just the on board 12 amp batteries and still had to pedal assist but it was easier. Even with the trailer I had an easier time of it than Joe did. If one doesn't care about range I'm sure the 700 Watt motor would do the job unassisted. One problem for me was having the one rear drive wheel try to torque the lightly loaded front wheel sideways when I pedal-assisted. I think carrying a pair of auxiliary gel cells up front in panniers might help.
I wish you thing was longer. . . . .
Hauling that trailer along everywhere is getting to be a drag, literally, and I'm now thinking of lengthening the frame to accommodate the batteries and maybe a passenger. Here is a Photoshop hack to consider.
On the waterfront they say "The girls are cheap, it's the dresses that cost!" and the latest dresses I've bought for this thing is a pair of Schwalbe Big Apple 20 x 2.35 suspension tires for the rear wheels. I run them at 22 psi and the ride is verrrry smooth.
2008 Update
This outfit spends a lot of time in storage between seasons and I've had warrantee issues with the motor which resulted in the batteries getting pretty neglected. According to the book they should be topped up with a charger every 30 days. When I got the replacement motor installed this Spring I discovered that the batteries had failed. I checked back with David and Gil at Northern Battery's warehouse #7 and got a couple 95 Amp valve-regulated lead acid AGM gel cell batteries.
Here is how the outfit looks this year.
'09 Update
I have been experimenting with an '88 Ford diesel pickup this year.
I collect used (clear, not creamy) restaurant cooking oil and drain it though a filter made out of blue jeans with the cuffs sewn shut, then mix in 10% regular unleaded gasoline and re-filter with a 10 micron industrial sock filter that has a a single blue jean pants leg filter inside it. I then burn the blended fuel directly in the engine. The truck has two fuel tanks so I use one for the blended cooking oil and the other for strait diesel fuel. I start up and shut down on diesel. I switch to blended fuel when the engine is warm. If I don't figure in the cooking oil I make over 150 miles per gallon.
=)
I burn the cooking oil about 8 months out if the year which is the same as the seasonal use I got out of the electric trike, so with this shift in interest I listed the electric trike on Crag's list and it is now living in Iowa.
Photos via Olympus SP-700 camera