Speed and power limit with new motor
Hi dear Sondors community,
I am experiencing a very strange problem concerning the speed limit on my Sondors Custom 350 watt 36 volt fatbike. Since neither me nor the Luna Cycle support was able to figure out what the reason for this problem could be, I hope that maybe somebody in this forum can help me with this issue!
The situation is the following:
I have two Sondors Custom 350 watt fatbikes, both are equipped with the Luna Cycle KT LCD3 Display and the Hot Rod 20 amp controller, both worked fine and top speed was approximantely 25 mph. one of them at one point had a motor damage, therefore I ordered a new motor from Ebay and installed it succesfully. It should be the same Bafang 350 watt motor, just the axle is slightly broader, the wattage and volts are the same after installing the new motor (and despite checking the recommended KT-LCD3 settings like 20 times) this fatbike with the new motor had a speed limit of approximately 18 mph which seems to be impossible to remove since I switched both, the controller and the KT-LCD3 Display, from one bike to the other to check which component could be causing this problem, I am pretty sure that these components are working fine. But the bike with the new motor is limited in speed and max wattage no matter what I do. I was told, that the Display is responsible for the speed limit, but since I've tried to switch Displays, it seems impossible to me that this could be the cause for this problem.
Anybody has an idea how I could remove this speed limit?
Thank you very much folks!
For those interested, I attach the conversation I had with Luna Cycle trying to figure out what the poblem is, they suggested to ask the Sondors forum for help since neither they knew what issue could be the reason for this strange limit.
written by Mike Ritchie – B/Y Storm e-bike owner
Here are a few pictures showing the "no power" issue caused by a brake switch being
triggered. If you've charged your battery, inserted it correctly and have your battery
switch turn to "on", and you confirm that the LED lights on your handlebar throttle
illuminate, BUT you don't get power (or intermittent power) the issue is likely with your
brake cutout switch. This bike is designed to cut off the motor when the brake levers are
depressed, even a very small amount. This issue can be caused by brake cables with
too much slack, creating play in the brake lever.
In this first picture you can see a properly
aligned brake with no slack. The lever is
fully released and there is no gap between
it and the housing. This is how things
In this second shot I have depressed the
lever ever so slightly. I'm doing this manually,
but this can also be caused by slack. The
brake cable should be tight enough that this
doesn't happen due to just being loose. A
gap this small will cause your power to cut
Here's what happened to me. I had things
installed correctly, but I didn't notice that the
brake cable itself found its way to a position
where it kept the brake lever from fully
releasing. Once I read that the brakes could do
this (thanks guys) I quickly found the issue. My
cable is now out of the way and snapped to
other cables to keep it that way. Hope this all
Assist mode - pulse or constant?
I have 2 original eBikes with LCD, the first one (my girlfriend's) assist mode pulses - so as she pedals steadily the assist pulses on, then off, then on, then off - automatically.
On my ebike that came in a few months later my assist mode is constant - it doesn't pulse. As I pedal steadily the motor constantly assists, which seems like it would discharge the battery faster.
Which is the correct assist mode and how do I change between pulse and constant?