Anyone else had this problem?
One day while zipping along to work at 20Mph there came a horrible grinding sound from my front wheel hub motor. I thought it might be the brushes had worn out but what had happened was one of the permanent magnets had come loose and lodged against the inside of the motor. It was getting ground down as the wheel turned. I didn't go very far before needing to take apart the motor.
When I took apart the BD36 hub after 3 years of hard use commuting to work, one of the magnets was loose. I used some permabond 910 adhesive and stuck it back on in the right spot with the right orientation. It held up for another 9 months running at 48Volts until the brushes went out. When I took the motor apart again to replace the brushes, the same magnet that I had scribed an arrow into was loose again. This time I wasn't messing around. I took some marine epoxy, surrounded all the permanent magnets on the hub and ground down the excess until the surfaces of the magnets were exposed. This has been running for a few months now at 48V without a problem.
Don't! throw away your hub motor when it dies. Send it to me and I'll fix it. These things will last forever if you do the right thing to make them work. I like the brushed motors better because the controllers are cheaper, you could use direct DC with a little dial to control the voltage if you wanted. I'm still using the original 3 year old Wilderness BD36 controller at 48V. Yes, the brushes wear out, but I found some old motor brushes, ground them down to fit and away I go again.
Yes the batteries are costly, but I've found that if you charge at 12V in parallel SLA batteries are still cheap enough to offset the cost of my 10Mi daily commute. I figure I'm spending less than $0.50/day burning up recyclable SLA batteries every 5-6 months. I'm sure it would cost more if I used NiMH or Lithium batteries.