There's all sorts of discussion on this forum on this it's been discussed many times. Might I suggest you use the search function on the forum and you will get all sorts of discussion regarding this. Oh and welcome to the XP ForumI also have 2 XP's. I've had them for about a week now and have tried to change some of the mode settings. I had no problem changing Mode 08 from 32 to 45, but I tried to change Mode 06 from 20 to 22.4 (which is the actual wheel diameter) and the up nor down key on the controller pad will not change the setting. I have the same question, are some modes locked? I would like to be able to change this setting since my indicated speeds and odometer reading are about 20% lower than smartphones GPS bike app indicates.