[Bafang + Nuvinci] Cargo bike seizes up in hills
08-31-22, 11:28 AM
#1
Senior Member
Thread Starter
Join Date: Aug 2011
Location: Paris, France
Posts: 2,497
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 573 Post(s)
Liked 118 Times
in
99 Posts
[Bafang + Nuvinci] Cargo bike seizes up in hills
Hello,
Remotely, I'm trying to help a non-techie who bought a Dutch-made used cargo trike in good condition from a bike shop.
1. It has a Bafang M400 mid-drive (MM G33.250, 36V 250W 14A; It's in Europe, hence the 250W motor)), and a Nuvinci Optimized 330 gear hub with an automatic shifter + H3 controller.
She intends to ride her handicapped 30kg kid to school on 4-6% grade hills — so, not really steep, but not flat either.
The issue is that, when climbing, the motor just stops: The pedals won't go forward, but she can backpedal.
FWIW, she chooses the one dot mode on the H3 because the bike barely moves in hills when using the other two modes, especially the three dot mode (where you spin the most).
Could it be the 80Nm torque of the Bafang is fine, but a 36V battery isn't up to the task, and the controller shuts it off to preserve it? And/or something to do with the electric Nuvinci shifter?
2. As a lesser issue, when she recharges the battery — after letting it cool off as recommended —, the charger gets quite hot, although it came with the bike.
Thank you.
Remotely, I'm trying to help a non-techie who bought a Dutch-made used cargo trike in good condition from a bike shop.
1. It has a Bafang M400 mid-drive (MM G33.250, 36V 250W 14A; It's in Europe, hence the 250W motor)), and a Nuvinci Optimized 330 gear hub with an automatic shifter + H3 controller.
She intends to ride her handicapped 30kg kid to school on 4-6% grade hills — so, not really steep, but not flat either.
The issue is that, when climbing, the motor just stops: The pedals won't go forward, but she can backpedal.
FWIW, she chooses the one dot mode on the H3 because the bike barely moves in hills when using the other two modes, especially the three dot mode (where you spin the most).
Could it be the 80Nm torque of the Bafang is fine, but a 36V battery isn't up to the task, and the controller shuts it off to preserve it? And/or something to do with the electric Nuvinci shifter?
2. As a lesser issue, when she recharges the battery — after letting it cool off as recommended —, the charger gets quite hot, although it came with the bike.
Thank you.
09-01-22, 05:27 AM
#2
Full Member
It's normal for a charger to get quite warm to the touch. Is the battery getting a full charge?
You say automatic shifter. Does she actually shift, or does she think the bike has an automatic transmission?
When the problem occurs does the motor make noise when the throttle or pedals are pushed
You say automatic shifter. Does she actually shift, or does she think the bike has an automatic transmission?
When the problem occurs does the motor make noise when the throttle or pedals are pushed
09-02-22, 03:52 AM
#3
Senior Member
Thread Starter
Join Date: Aug 2011
Location: Paris, France
Posts: 2,497
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 573 Post(s)
Liked 118 Times
in
99 Posts
Thanks for the info. So there's no reason to worry the charger is underpowered for that battery.
Yes, the battery is fully charged.
She doesn't shift: The Harmony autoshifter takes care of that. On the shifter, she uses the "one dot" cadencing because with the others (two/three dots), she just spins without the bike moving much ahead.
No noise when pedaling (no throttle, as this is Europe.)
I suspect it's the Nuvinci, and advised removing the rear wheel, and using a plain wheel, either single speed or with a cassette but without bothering installing a derailleur + shifter. We'll see if that solves the issue.
Yes, the battery is fully charged.
She doesn't shift: The Harmony autoshifter takes care of that. On the shifter, she uses the "one dot" cadencing because with the others (two/three dots), she just spins without the bike moving much ahead.
No noise when pedaling (no throttle, as this is Europe.)
I suspect it's the Nuvinci, and advised removing the rear wheel, and using a plain wheel, either single speed or with a cassette but without bothering installing a derailleur + shifter. We'll see if that solves the issue.
