Rear sprockets steel Afam chain 520 for KTM 890 Adventure R 21-24 SLK self-cleaning

THE PHOTO IS GENERIC AND NOT REPRESENTATIVE OF THE PRODUCT FOR THE DIMENSIONS REFER TO THE TECHNICAL DRAWING

AFAM offers all enduro and motocross riders a line of self-cleaning steel chainrings, with long life and minimum weight, designed for all types of terrain and in any weather condition: the SLK series.
For these chainrings C45 carbon steel is used with normalization treatment (N) and about 19HRC hardness; the teeth undergo an additional induction hardening to obtain a final hardness between 45 and 50 HRC on a depth of 1-2 mm.
To comply with dimensional/geometric tolerances and avoid any mechanical deformation of the steel, SLK crowns are made entirely with high precision CNC machines.
The design is optimized for maximum weight reduction without sacrificing performance and reliability.At the base of the teeth, on both sides, special grooves are made which generate centrifugal self-cleaning, thus allowing the chain to always work on the entire surface of the tooth in case of use on muddy or sandy terrain.

By choosing the ratios, 1 front sprocket cog is equal to about 3 rear sprocket cogs (the exact ratio is given by: number of rear sprocket teeth / number of front sprocket teeth).
The above stated, ratios have to be chosen in a way that a max. difference of 2 cogs is not exceeded. This way, you can always keep the same chain length. The Kawasaki ZX-10R Ninja is an exception: a rear chain with over 1 tooth more than the stock one cannot be used, since length of stock chain will not allow that. Remember that if you want more acceleration you have to mount a rear sprocket with more toothing, or a front sprocket with lower toothing. Ratios have to be necessarily and exclusively chosen by yourself. It is usual to mount a rear sprocket with 2 teeth more than the stock one, but that is however a medium choice which does not mean to be satisfying to everybody.
In a circuit, generally the right final ratio will be that allowing to achieve, at the highest gear, about 200 rpm more than the max power rate, always staying 200 / 300 rpm under the maximum rate the engine can reach. This way, you can take advantage of the trail of the driver who is preceding you.
Choosing the final ratio, remember that the bigger it is, the more the acceleration will be. But if it is too big, you will lose speed. If on the contrary the ratio is too small, you will lose acceleration and will not manage to reach the maximum speed.