Hello all, first post. I hoping to run my very first Iron Butt ride this year (SS1000 out of the Memphis area) and joined here to start learning the ropes. Why use two Garmins? I like the idea of having two sources for data like one for trip guidance and another for live weather info for example but why two Garmin GPSs?
Good question and best wishes on your first SS1000 run.
There are two types of events in the Long Distance riding community: 1) IBA Certificate Rides and 2) for lack of better terms, Scavenger Hunt Rallies. The Certificate Rides are like your upcoming SS1000. The Scavenger Hunt Rallies are somewhat different in that you have a list of bonus locations that have their own point values. The challenge is to reach and claim the most valuable set of bonus locations in the time allowed. Some rallies are 24, 32, 33 hours in length and some of the more advanced rallies are 5, 6 or up to the big dance, the 11-day Iron Butt Rally.
My bike is set up to run the Rallies. In my approach, I use the Zumo 660 to hold my base route for the day or event. Being the most optimistic, the Zumo displays my endpoint arrival time. The Dezl is used more for point-to-point timing and for what-if evaluations. It is the most pessimistic in the arrival time calculation. I use it to display the arrival time and/or distance to the next bonus location. Often the two Garmins will not agree on the route so the iPad comes into play. It also has the best traffic reporting features.
That's just my strategy. Others use their equipment in different ways. Your results may vary.