Daily Archives: June 3, 2012

We went to see Dad yesterday, Wreck-free Sunday

For those wanting to know how Dad is doing we took time out of creating yesterday’s post to go visit Dad in the hospital and find out what’s what. He’s gaining weight, slowly. He’s recovering from the opportunistic infections he got because he was weakened by not eating. To be succinct, he is recovering slowly. The main barrier to his getting better more quickly is his poor state of nutrition, which was mostly due to his long-tern minor depression, which is something else they are trying to get a handle on. When all this stuff is under control, then he will be sent to long-term care to gain weight and get strong enough to return home. I foresee Dad being able to attend Thanksgiving dinner in TX this year.

As I have mentioned a few times in the past, I’m a big proponent of e-assist to maximise human range by letting the rider do what people do best, delivering steady low power outputs for a long time, while using assist to do things that motors and batteries do better than people, delivering bursts of high power efficiently. This is the crux of an extended argument that has been going on in the Yahoo group power assist for about a year and a half between John A. and Randy. Randy has been arguing about testing with pedalling, saying that it muddies the data by adding human power to the battery output. John has been saying exactly! you need to be testing an assist bike while pedalling because they are not scooters but bicycles with assist. I have been using the simulator at ebikes.ca and their less-expensive NineContinents hub motor coupled to the LiFeBatt P20 cells (because I have the detailed specs on those cells needed to plug into the simulator and also to estimate pack weight). I plugged in a standard weight of 330 pounds from the drop-down menu, and went back and forth between the various motors and wheel sizes available from their store (and controllers) to find the combination that would climb well without overheating but be pretty much all done at 20 MPH and 6% grade with between 100 and 150 Watts of human input. Climbing at 20 MPH with a touring load (the 330 pounds GVW I based the simulations on) takes more power than most humans are able to put out for more than a couple of minutes. The combination of the right motor and wheel size with the right battery pack will allow climbing without overheating and cruising on human power for flat to mildly rolling terrain. I’ll leave the selection of motor and wheel and battery pack to my readers (I have made the choice for my bike, but I don’t want to deny your fun of using the simulator). If the rider has access to grid power during the ride with the bike, battery, motor, and wheel I have selected you can make a lunch stop and recharge for about an hour and have about 300 miles of range in a single day’s ride with enough clothes to have an indefinite duration stay at your destination and also an indefinite number of days on the road, assuming access to laundry facilities (300 miles will take about 17 hours total, 15 hours on the bike). If you can ride 300 miles a day on an e-bike with all the clothes you need when you get where you need to go, why would you need a car?

PSA, Opus

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