throttle/speed appears to get reduced

[mikek]

have searched and can't find anything like this. Went for morning ride with wife and about half way thru I look back and she's fallen way behind even when trying to catch up using throttle or higher level PAS. seems she is limited to 12.5 mph, unless totally self powered herself. In testing it I can see where it will take off like normal and seem to go, but then it slows itself down maxing out at 12.5 almost like it hits a governor. Any ideas? Had about 18 month and no issues except initially had to replace the digital display and wiring as the motor stopped completely engaging.  Thanks in advance.

[JimInPT]

Which bike and which country?  It seems at first that your controller has been reset somehow to a different top speed or power output limit.  It's also possible that the wheel-diameter setting might be wrong; that will affect what speed the controller thinks the bike is traveling.  The settings are often limited by geographical sales region as well, sometimes as pitifully low as 250 watts in nations that don't want you traveling very far I suppose.

On stock controllers, you can set some things on the main setup menu, others (including top speed limit) on a "hidden" menu (instructions to get into it vary by bike model) and I'm not sure if the factory controller allows access to power limit at all - I've replaced my controller with a 35A upgrade and the standard menu allows access to all of these and much more.  I just can't remember which are allowed via the factory controller.

Best wishes tracking it down and I hope it's just a setting issue and not a component defect.  If your bike is still under warranty that would be a hassle but not a big expense.

[mikek]

Rad Rover 5, US. Had 13 months so all stock. Did replace original controller due to short for brake lights, replaced with OEM from RAD under warranty. All was working well last week, jut started and not changes made.

[mikek]

Ok just checked the advanced menu and found the issue in that the speed limit setting was down to 20. No idea how that changed as never been into that before. Ramped up to 40 and wife all happy again. Now I need to do mine so I can keep up. Wondering if it's a sign the controller is acting up. If so I see an upgrade in the future. Thanks

[JimInPT]

Very cool!  Glad it was a simple menu adjustment and you figured it out on your own, which reinforces the idea that yes, we CAN fix our own stuff.   The recovering-engineer in my brain would stay bugged about HOW it happened though, like you.  Hopefully it's just a controller-brain-fart that won't recur.  Maybe a bit got flipped due to a stray cosmic ray during bootup for that ride (yes, that can and has happened to ICs although I understand it's very rare) or some other power-up glitch and it was just bad luck.  The fact the setting was cut in half exactly sorta leads that way; flipping the high bit in a binary string would exactly double or halve the result.

Happy trails.