help me
 

if i want to put a smaller sprocket on a bike do i have to buy a new back wheel and chain???if the original is a bigger one

1.) Do you have a cassette hub or freewheel hub?
2.) How old of a bike is it, and what type of condition is it in?

how many ****ing threads do you need man? there was already a thread on the first damn page about exactly this topic, no need to even use the search button. i posted a link to it in your other one.

yea two threads is a tad ridiculous. and on the chain part, no you dont need a new one. all you need to do is get rid of some links from it