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72v TSM-A5 vibrates,throttle cuts off, no regen

dab

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Joined
May 10, 2026
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I would be very grateful for a second opinion on the problems I'm having with my ebike.

I have two identical 36v batteries in series feeding a Phaserunner and a CA3 powering a TSM-A5. The bike runs great under acceleration until it hits about 32-35mph (52-57kph) at which point there is a loud and noticeable vibration from around the motor before the throttle cuts out. I have to release the throttle fully and wait a few seconds before it will provide power again. The same thing happens when I try to use regen. It vibrates, then regen cuts out.

I've torqued everything down including the torque arm which I did to the manual's specs. I've removed all the extraneous attachments, ie basket, rack, fender, etc, to isolate the source. I've even trued the wheel to be sure it's not causing the issue. I can't identify the source of the vibration. I've adjusted the max power up and down and jacked the rear wheel to observe the behavior while stationary. I tried attaching the CA3 setup file but it isn't allowed.

I have a 40 mile 65km commute that I'd like to keep close to or under an hour, if possible, which is why I'm reaching for these higher speeds. Ideally I'd like to cruise at 57kph because this gets me to work and back fastest on a single charge. I would appreciate answers relating to my issue and not opinions about whether that is safe or wise unless higher speeds with this motor are a known limitation I'm not aware of.

Does anything stand out to you? Have you encountered an issue like this before, and if so what was the cause? Is this a known limitation with the TSM-A5?

Your help would be tremendously appreciated!
 
I posted this link on another thread you posted to:
TSD-A5 failure
As I said in that link--open the motor and look inside. The wires could be nicked. Try running the Phaserunner program first if you have the cable and see what that says.
It's a defective motor design. Maybe contact Grin first. It would be a win if they gave you an All-Axle, though you would also need a new controller. My motor was over 2 years old when it failed, so I repaired it. It now works on throttle, probably sensorless.
 
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I posted this link on another thread you posted to:
TSD-A5 failure
As I said in that link--open the motor and look inside. The wires could be nicked. Try running the Phaserunner program first if you have the cable and see what that says.
It's a defective motor design. Maybe contact Grin first. It would be a win if they gave you an All-Axle, though you would also need a new controller. My motor was over 2 years old when it failed, so I repaired it. It now works on throttle, probably sensorless.
Boy I wish I'd seen that post before I bought mine. I'm kicking myself for not getting the AA in the first place and have a feeling that's where this is headed. I'll check the Phaserunner and see what it has to say.
 
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