How to choose your sprocket number of teeth?
You can choose between a one piece driver with 10t (for most BMX style cranks) or a two pieces driver with a 14t sprocket (for most MTB style cranks. In that case you can replace the sprocket for one from 12t to 16t).
We advise you to get a gear ratio (chainring:sprocket) between 2:1 and 2.7:1.
2.7:1 means that the chainring 2.7 times larger than the rear sprocket, or that the rear wheel will make 2.7 rotations for every full rotation of the cranks. With this ratio, the bike will be quite difficult to accelerate but will be easy to maintain a high top speed.
With a ratio closer to 2:1, the bike will accelerate quickly but soon "top out" and you will be spinning hard.
Example for a 2.7:1 ratio: 27 / 10 or 38 / 14
Example for a 2:1 ratio: 20 / 10 or 28 / 14
Most standards slopestyle MTB gear ratios: 25-24 / 10 or 32 / 14