I just got back from a successful 25 mile test run on the recumbent. It was epic! Here's a photo from the far point of the trip: a convenience store that's the turnaround point for this route when I'm riding lycra:
(Kin - you will recognize this sign if you've ever been out US-98 toward Creedmoor Rd.)
Performance is GREAT - exactly what I was aiming for. I easily cruised at 20-23mph and if I "goosed" it, I could maintain 25-27mph. 30-31mph on even a slight downhill. 30mph is plenty, plenty fast for a non-suspended bicycle. I felt comfortable in the 23-25mph range.
The 9c 2810 motor ROCKS. No, it ain't the fastest thing on the block, but let me tell you, it sipped power and hauled my butt down the road at 30mph when I asked it to. The LiPo held up great. It's an incredible battery.
450Wh to go 25 miles. 17.8Wh/mile, close to what I got on earlier test runs. I pedaled what I'll call a "fair" amount, always working to keep power under 1Kw. I'm happy about that also - it's been my intention to get exercise on the bike - when I got back home, I felt I'd worked, but it's not at all like when I get into the lycra and pedal hard. I feel tingly and invigorated. I definitely think I'd be OK for the day in the office with a tee-shirt change on arrival.
I am a little concerned: I'm not sure if I have the capacity in my pack that I thought I had. After that 450Wh, the pack was sagging into 68v territory. I calculated I have a 1KWh pack and I didn't expect to go below 69v before using half that.
The opposing wind (the normal wind from the southwest here) was fierce. I gained an acute appreciation for what everyone's been saying about wind resistance being far more important than weight.
The important gears on the drivetrain were:
- "very low" using middle front sprocket to get started
- at speed, the highest gear to assist the motor
I would climb through the low gears, enable the motor, then shift up to the large 52T up front and the little 11T in back for cruising. It was a lot to keep up with, but it really helped me stretch out the battery. It's a strange feeling to pedal a bike going 30mph!
The motorized recumbent isn't any more stable than before, maybe less. I already had a "feel" for a recumbent, but the added weight and speed intensify that feeling of instability. It's something I'm going to think about a little more before I decide to do this as a routine commute.
I'm a big boy using a big motor with a big battery. With me on it, I bet the entire rig was 330-340lbs. When I got back home, you could hear the spokes "pinging" on that little 20" front wheel. Probably the next ebike upgrade is for me to lose some lb's... More Work To Do
The test run showed up several problems:
My battery harness came loose in the battery box at one point, so I know I have more work to do to improve how my wiring survives the vibration.
My rear fender sucks - it won't stay lined up with the tire. I think I need to twist it with some heat.
My lights suck. They are ordinary AA and AAA powered bicycle lights. They worked, but they don't cut it. I want to make something way more powerful and use a DC-DC converter as the power supply off the main traction pack. This little battery action doesn't cut it.
It got dark on me before I got home, showing me that I should add more reflective materials to the bike.
The front wheel spokes started "pinging" by the time I got back - so the wheel will need to be trued.
I want real regen - I got a little bit, but I want to add brake levers with the regen switch. There were at least six points on the ride where I could have really used some regen.
The 8 speed freewheel just doesn't work with this bike. I need to drop down to the 7 speed freewheel (with the 11 tooth "tiny gear")