9 ft/sec for an 8" wheel drive?

[SerpentEagle]

So according to my calculations with this spreadsheet I made, the max speed you can get with a 6 CIM 8" wheel drivetrain is around 9 ft/sec. I've used JVN's design calculator, but noticed that it doesn't account for torque loss (correct me if Im wrong).

Do these numbers seem right? I calculate speed based on gear ratio, torque loss, and mechanical efficiency; here is the spreadsheet: https://docs.google.com/spreadsheets...it?usp=sharing