as far as i can see there is no way to change any of the settings buy the end user on that display so if the wheel size needs to be changed only a dealer would be able to do it with the software.
tho you could try holding one of the buttons and powering it on as on the first displays you did this buy holding the select button and powering it on.
Thanks. That's pretty much what I thought, sadly. I was going to change the wheel size to 29". I can do that easily with my Woosh-equipped Brompton, but not on the Haibike.
only a dealer can do that as i could change the wheel size on my bosch bike with the intuvia display but if i tried to go from 27.5 to 29 it would just throw up errors as can only change it a tiny amount imo for different size tyres.
you could use a dongle then the wheel size wont matter.