Usually the sprocket is an inseparable part of the freewheel, and the size of the freewheel is determined by the hub.
Yes, it will work. If it'll be the best for you or not is another question.
yes
Yes
you don't use a freewheel for a 23 tooth sprocket you need a cassette hub heres gear ratios for yaSprocketF/W or Cassette2282382592810301133123613391441154416
Not a sprocket only, but you can buy a 23-tooth freewheel that should fit.
they don't make a 9 tooth freewheel they make a 9 tooth cassette and its better to get a 8 tooth as you can see heres a gear ratio for you to look atPopular Gear CombosSprocketF/W or Cassette2282382592810301133123613391441154416
yes but it will be really easy to pedal
No. a 9T sprocket will only fit a cassette hub, and not freewheel hubs.
Ok- the question was will it fit and the answer is NO. A 18 tooth freewheel has standard threads and will fit most any freewheel threaded hub. With one exception, the standard freewheel hub can accept 16 tooth and larger freewheels.Sometimes a hub also has metric threads on the opposite side and will accommodate metric threaded freewheels which are available in sizes 13 through 15 tooth. Your 14 tooth freewheel is metric and will only fit hubs with a metric side on them. Such hubs are generally termed flip flop hubs because they can use both types of freewheels.
Unless by freewheel you mean driver (in which case 8-9) I haven't ridden bmx in a few years but last time I checked the smallest freewheel you could buy was 12 tooth which would make for quite a low ratio
I'm assuming you're talking about a BMX here, which use the words a bit different from the rest of the cycling world.So it's the size/tooth count of the freewheel that you're asking about.And then it's just as much about what you want as what you need.When you change the sprocket/freewheel size you change the gear ratio.A big sprocket and a small freewheel lets you go fast, but you'll have to push harder.A bigger freewheel will cost you some top speed, but will make it easier to get the bike moving.A very common combo is 25t front and a 9t rear.