After a few lessons learned, and wanting to make the system easier for other people to start using, I revised the data entry table, to make it easier to use and lowering the risk of messing up the equations. I also added a "Next ETA" field to the main display, so the organizers can quickly see when the riders should arrive at the next checkpoint.
I am willing to share my work to others interested in tracking an event like this. My current version will track up to 200 people, and up to 10 checkpoints of calculations. I can expand this, but I wanted to keep the file size down for now. The current version does load on a 1st Generation iPad via Safari. The webpage is hosted on a Windows computer, running Internet Information Services as the hosting method. This could be used on a real website, to give this data to ride participants and support personnel if the Excel file is regularly uploaded to a public website. This version must be edited on a computer running either Excel or Open Office. Pages on the iPad will delete some of the complex equations because it does not support some of the methods I use for the math.
If you are interested, just send me an email or post here. My Email address is current on QRZ.COM