Bmx Sprocket

Do i have to replace my freewheel on my bmx bike to put on a smaller sprocket?

I am getting a bmx bike with a 30t sprocket and i want a 22t sprocket do i have to replace the freewheel to?

wow alot of people dont know what there talking about here lol. yes you will have to change it like one guy said a 22 tooth sprocket/chainwheel you will need a 8 tooth but thats to get a 2.75 area gear ratio. that means for every one full rotation of your cranks your back wheel goes around 2.75 time i ride 28-9 and 25-9 all the time the higher your gear ration the harder it will be to pedal and the lower your gear ration you will be pedaling like a mad man..
also sorry there is no free wheel that small. you will need a new rim that has a casset hub and driver. to get a a normal pedal feel. also they dont make a 3/8's driver axle that im aware of so you might want to look into it more so that the rim will fit your bike you can pick up cheap rims at danscomp.com some cheap as 100 bucks... but for a 22 you will want either a 9 or 8 nine will lower your topspeed but faster acceleration 8 lower accel higher top speed. i would get a 25-9 haro conversion kit they have there.

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