I don't think you can openly carry on your bike yet because of the whole loaded guns and motor vehicles thing. I think you need to wait till Nov.1 to do that, and if you don't have a permit with reciprocity, then don't drive through school zones.
Edit: I just checked the New to Open Carrying in WI, Here's what you should now. thread, and I also confirmed it in the law, no vehicle carry, be that car or motorcycle. You'll have to plan a ride in the late fall if it's not too cold or wet or wait till spring to OC on a motorcycle.
"(h) “Vehicle” has the meaning given in s. 340.01 (74), and
includes a snowmobile, as defined in s. 340.01 (58a), and an electric
personal assistive mobility device, as defined in s. 340.01
(15pm), except that for purposes of subs. (4) (c) and (cg) and (4m)
“vehicle” has the meaning given for “motor vehicle” in s. 29.001