The output of your motor will varry a lot depending on a multitude of variables: rider weight, gearing, wheel size… i think there might be more but that could be it.
Overall that 1850w is the max yes… but we have science somewhere on this forum that shows you are actually never drawing more than like 400w. A lot of people use a motor very similar to the one that you have linked, then they put a 6s battery and the VESC (Vedders ESC) to keep the motor spinning and get a respectable 20mph on average. Again, this can vary based on weight, wheel size… blah blah blah.
put simply: safety. If you get a car ESC from hobby king and get it all set up, you are putting weight onto a motor that was meant for an RC car/airplane… itll do it, but she will get super pissed. Mise’ well have a lot of wiggle room so that you always have that safety ceiling. If you get lipo batteries and have a short… you risk having a nice fire that looks a lot like thermite welding. The only ESC that was made specifically for our boards, both long and short, is the VESC.
If you search around on this forum and check out others builds you will find that a lot of people follow the same pattern, get a VESC, get a LiFe battery (like the space cell) throw on a 36 tooth wheel pulley to some 83mm abec flywheels, throw a 14T pulley to that motor you linked, mount it with one of the many motor mounts out there, strap it all under the board, and ride happily for days. Usually they have two motors no less lol
If you can spend the ~$100 on an ESC get either the VESC or torqueboards 12S ESC. you will have to do some learnings regarless though. have fun!!!