Tom, thanks for the offer to deal with tech problems. When you got my email dated 11/1 and reproduced below, you did reply with a comment about the bike. (And yes it is cool; if I can get a photo pasted into this reply, other members will surely agree with you.) But I asked for technical assistance and still await your reply.
From: Lloyd Morris <lloydmorris@cox.net>
Date: November 1, 2009 6:31:44 PM PST
To: nicholas@arizonaebikes.com, Philip Yao <sales@goldenmotor.com>, Yao Yuan <yaoyuan@goldenmotor.com>, echo <echoxu@goldenmotor.com>, Tom <zhourenli@goldenmotor.com>
Subject: Battery success and (sigh) motor failure
Hi To All,
Here are two of my grandchildren posing on "Our Other Car".
And here is the handout that I made because so many people ask about it.
Our Other Car
The Drifter, a steel frame, foot forward, 7-speed cruiser tandem by Sun Bicycles with
a 500 watt brushless hub motor and a
12ampere-hour, 36volt, lithium-ion battery pack by Golden Motors.
Accessories include two racks with four Performance grocery-bag panniers, first aid & tools
plus a Watts-Up power monitor, bike computer, lock, lights, horn, level & water bottles.
Total weight: bike with everything listed above is 100 pounds, and
payload can be: riders up to 350 pounds and groceries, etc, up to 80 pounds.
Total cost $1600 including bike $600, motor $350, battery $400, accessories $250;
can be cut to $900 including bike $300, motor $350, battery $200, accessories $50.
Range is over forty miles of mixed hilly and level terrain with a total climb of over 600 feet
like riding from LaMesa to the beach & back or twice to El Cajon & back.
Top speed about 20mph; maximum grade about 7% with fit riders plus motor.
Fuel economy: four cents for a full charge, and 20 miles on a pound of pasta!
Wanna know more? Email lloydmorris@cox.net or call me at 619 460 8400.
The new battery performs flawlessly and we love it. Sadly, today, the motor died. I suspect the Hall Effect sensors but don't know enough about such things to be sure. Here are the symptoms:
Abrupt onset of continuous strong vibration and almost total loss of power.
With the throttle set for full power, a current draw (on my Watts Up meter) of only about six amps
Dead spots; even with the motor wheel off the ground, it may not start without being first turned by hand.
Here is one more that I added in my followup email (on 11/6)
When the motor is turning at just a few MPH, its now low power comes in discrete pulses as it passes the many dead spots during each rotation.
The motor was ordered 10/10/07 and was installed and first run on 1/13/08. (I don't recall when it arrived but it took a while to build a classy battery box that fit gracefully on the bottom tube, between the cranks.) It ran on SLA batts until we installed your Li ion battery this past July. From August, 2008 to Feb 2009, it was idle while we were in New Zealand. So it has been in use for only about sixteen months and then only lightly. I am confident that we averaged no more than 100 miles per month during those sixteen months.
Please tell me what you can diagnose and/or advise.
Regards, and apologies for being such a nuisance,
Lloyd
