I don’t have a method of recalibrating the speedo, but I was wonder what size of tires you upgrade to, I have the Ultimate with 20” and still original tires since 2019 and was hoping I could put a larger tire on, but haven’t inquired as to how big I could go and yes I too was thinking whether I’d have to recalibrate.
Do reply when you do find out about recalibrating and the size of tire you decided on if there also 20’s.