Originally Posted by
jlfx car audio
...almost every motor these days comes with a 12.5 rotor ... Orca/trac-star (all I run ) and I'm sure if this becomes a issue motor motor manufactures will spec theirs with a 12.5 if they already don't come with one ...
You're right, so the USGT rotor rule really makes no sense. It just penalizes the people who buy a motor that doesn't come with a 12.5mm HT rotor. They aren't allowed to just put one in later on. They would have to buy a whole new motor. Also, lets say you've been running the same motor for a while and it's gotten hot a few too many times and is noticeably slower because the rotor has lost some magnetism. Often just changing to a fresh rotor can make an old sluggish motor perform as good as new again. This rule says you can't do that. You would have to buy a new motor if you want to follow the rules to the letter. Even though there would be absolutely no way to determine that you changed it. It's just a rule that makes zero sense.