Hi jags!
Here is the product manual for your Blackburn Atom 4.0:
http://www.blackburndesign.com/blackburn/wp-content/themes/blackburn//manuals/cyclometers/atom_2.0_4.0.pdfBe patient after clicking the link...Blackburn's server is slow as molasses.
If you need to call them, the number and hours are:
1-877-358-2239
Monday - Friday
9am - 7pm EST / 6am - 4pm PST
Email support available from here:
http://www.blackburndesign.com/customer-service/blackburn/contact-usreset wheel size 559
jags, here's what you do:
1) Remove the computer and flip it over. There's two buttons on the bottom, labeled SET and RESET. RESET puts everything back to factory defaults and adjusts core settings.
2) To set wheel size...Adjust the blinking digit (far left) by pressing RESET. Set and advance by pressing the MODE button (MODE button is the one on the right-rear when you face the computer).
3) Continue through all the fields. Press MODE to advance to set the odometer if you need to. Otherwise, press the RESET button again to back out and save or continue through the fields to the end.
from KM toMPH
Press RESET. Set & advance by pressing the MODE button (MODE button is the one on the right-rear when you face the computer).
Hope this helps,
All the best,
Dan.