Help motor-wheel linkage

Hi it's my first time posting here so if this in the wrong section let me know, I'm currently planning my ebike build and I have some doubts. I have a 141kv RC motor



It's 5kw nominal at 16s but i'm using a 13s-50Amp controller so max 2.5kw, my doubt is how to much reduction do i need, this " https://electricscooterparts.com/motorwheelgearratio.html " online calculator sais that,asuming max rpm arround 6500, with an 11 teeth sprocket in the motor and a 56 teeth one in the 26 inch rear wheel i will have a max speed of 102MPH!!! Both sprockets are avalible to me but it is ridiculous, so i need a lot more reduction.

One option i thought is a belt drive but i don't know how to calculate the size and how many teeth both pulleys need to have, also where i live they may not be avalible to me.

The other option is to desing my own sprockets and have them plasma cut from a solid steel plate, which is possible where i live.

So what do you sugest? Motor mounting and the rest of the build is not an issue.

PS: Sorry if misspelled something, im still practicing my english

You'll need at least two stages of reduction if you want positive mechanical drive to a 26 inch wheel. But getting the necessary reduction ratio is not the only problem you have by using a toy airplane motor on a bicycle. Without the airplane's air flow rate, you are likely to have overheating issues. And then there's the matter of the electronic speed controller. Toy airplane ones don't get along with heavy inertial loads like bikes, and e-bike controllers often don't play nice with high kV motors like yours.

The easiest thing would be to start with a traction motor.

Sorry i should have comented that previusly, I already took care of those issues, the controller is a vesc 4.12 that a friend fried and gave to me, I fixed it and made a custom sealed box with heaksinks for the mosfets and the DRV. The motor will be cooled with a 3d printed fan that will be fixed to the neck of the rotor below were the propeller goes.

The vesc recognices the motor and is able to drive it without a problem.