How do I adjust preferences on DS?

[turbosam6]

I need to change the tire size on my DS. It was on 26.10, and I noticed that my mph was off as compared to the timeslip. So I changed it to 28" tire (thats what I run), thinking thats whats wrong. It shows the change on the preference file, but the speed and feet measured are still wrong. Whats the deal? It acts like it did when I had the 26.10 as the tire size. Thanks for the help!

 

[TurboDave]

I'm not sure whether it takes that inot account or not. After severaly years of using DS, and not being able to EVER get the mph right (with any tire size inputs), I just gave up on using ANY of the calculated values. The displayed mph on the data screen for some reason is within 1 mph of what the speedo is saying

I've never understood why that it's like that.