Depends on if it's the older freewheel type rear hub or the newer cassette style rearl hub. Cassette hubs can take 9 tooth I believe, while the smallest freewheel is 15 or so.
Depends on the hub. A cassette hub will go down to 9T. Standard freewheel is 16T, but there are a few that go to 14 and 15.
they now make 8 tooth cassette hubs and 22 tooth sprockets to work for them. so 22 is the smallest out there so far
You might have to either lengthen or shorten the chain, depending on if you're getting a bigger or smaller sprocket.
It will if you have bmx (or bmx style) cranks.
First you need to be clear about what you're talking about.In regular Bike-speak, sprockets go at the rear, and chainrings/chainwheels go at the front.In BMX-speak, a sprocket goes at the front, and a driver goes at the rear.If you're speaking BMX, the most obvious difference is the size, the tooth count.For the same size driver, a bigger sprocket will make the bike slower off the start, but give it a higher top speed.For the same size driver, a smaller sprocket will make the bike quicker off the start, but give it a lower top speed.If you change the driver to match, start and top speed will remain the same, even with a smaller/bigger sprocket. A small sprocket will increase the ground clearance. Better if you're riding ramps as there's less risk of the sprocket/chain hitting the lip as you drop in. If you're not riding ramps, well, a smaller sprocket is still lighter, which is a kinda-sorta advantage. The downside is that the smaller they get, the faster they wear. And the chain wears too.
First you need to be clear about what you're talking about.In regularBike-speak,sprockets go at the rear, andchainrings/chainwheelsgo at thefront.In BMX-speak, a sprocket goes at the front, and a driver goes at the rear.If you're speaking BMX, the most obvious difference is the size, the tooth count.For the same size driver, a bigger sprocket will make the bike slower off the start, but give it a higher top speed.For the same size driver, a smaller sprocket will make the bike quicker off the start, but give it a lower top speed.If you change the driver to match, start and top speed will remain the same, even with a smaller/bigger sprocket.A small sprocket will increase the ground clearance. Better if you're riding ramps as there's less risk of the sprocket/chain hitting the lip as you drop in.If you're not riding ramps, well, a smaller sprocket is still lighter, which is a kinda-sorta advantage. The downside is that the smaller they get, the faster they wear. And the chain wears too.Changing to a smaller sprocket on the rear will make your bike heavier to pedal. If you're strong enough to keep cranking at the same speed as before, then your bike will be faster.
As far a the sprocket in the front goes, i think they make them as small as 22 tooth, and in the back, it is called a freewheel or a driver. Freewheels are generally larger and drivers are smaller. Drivers can go as small as 8 teeth i beleave.
First you need to be clear about what you're talking about.In regular Bike-speak, sprockets go at the rear, and chainrings/chainwheels go at the front.In BMX-speak, a sprocket goes at the front, and a driver goes at the rear.If you're speaking BMX, a small sprocket will increase the ground clearance.Better if you're riding ramps as there's less risk of the sprocket/chain hitting the lip as you drop in.For speed it doesn't matter, as long as you pick a driver with a suitable tooth count.If you're not riding ramps, well, a smaller sprocket is still lighter, which is a kinda-sorta advantage.The downside is that with a smaller sprocket, you will have to use a smaller driver. And the smaller they get, the faster they wear. And the chain wears too.
Not a sprocket only, but you can buy a 23-tooth freewheel that should fit.
i would assume you have cranks with a built in sprocket, if this is the case, you can't
the easiest way is to go to your local bike shop
change out the hub
There are two different hub designs for BMX, freewheels and freehubs. You need to know what you have if you want to replace the sprocket by the rear wheel.
A bigger front ring will take more strength to turn, but if you are strong enough it will give a greater top speed for the same rate of turn of the pedals than what a smaller ring would. Going to fewer teeth on the rear sprocket will do the same thing.