The issue they had/you're having with the motors sounds like one I've seen before. These motors have baseline Shimano firmware, and then each bike OEM tweaks a set of parameters to tailor it to the bike it's going in. Things like gear ratio/range, wheel OD, and motor installation angle are all functions of the frame integration by the bike brand.
We had a Norco VLT come in with erratic power application. Turned out it had the baseline firmware in it, rather than the SightVLT-specific version. We worked with Norco's e-bike techs (as opposed to Shimano) to get the bike-specific parameter set into the motor and it behaved much better.
Like my comment above, I find that a lot of troubleshooting for these things at shops is trial by replacement, rather than trying to find the issue. I will acknowledge that unless the software chucks a code and you get diagnostic data from the software, they (Shimano) don't have good manuals or guides to go by.
But using some intuition, and good sense, there are lots of ways to fix things in-place, rather than plunk out a good motor for one that just has the right software in it. That motor may have been shot, but in my experience so far, when a motor is shot - it gives no joy and generally makes angry (or no) noises). When a motor is misbehaving, it is generally software, or wiring.
March 3, 2022, 3:42 p.m. - rockford
The issue they had/you're having with the motors sounds like one I've seen before. These motors have baseline Shimano firmware, and then each bike OEM tweaks a set of parameters to tailor it to the bike it's going in. Things like gear ratio/range, wheel OD, and motor installation angle are all functions of the frame integration by the bike brand. We had a Norco VLT come in with erratic power application. Turned out it had the baseline firmware in it, rather than the SightVLT-specific version. We worked with Norco's e-bike techs (as opposed to Shimano) to get the bike-specific parameter set into the motor and it behaved much better. Like my comment above, I find that a lot of troubleshooting for these things at shops is trial by replacement, rather than trying to find the issue. I will acknowledge that unless the software chucks a code and you get diagnostic data from the software, they (Shimano) don't have good manuals or guides to go by. But using some intuition, and good sense, there are lots of ways to fix things in-place, rather than plunk out a good motor for one that just has the right software in it. That motor may have been shot, but in my experience so far, when a motor is shot - it gives no joy and generally makes angry (or no) noises). When a motor is misbehaving, it is generally software, or wiring.