If you're using a 1/2 x 3/32 chain (or "10-speed chain") on your BMX bike, you're out of luck. You can't half-link those chains. If you have a 1/2 x 1/8" chain, you can buy what's called a "half-link" (go figure!). I've seen them range from $2 to $10 and they go in place of 1 1/2 links in your chain to get you that ideal chain length if you find you don't have enough drop-out adjustment to prevent either a too loose or too tight chain.
A half link chain is a type of bicycle chain that has links that are half the length of a standard chain. This allows for more precise adjustment of the chain length, making it ideal for single-speed bikes or BMX bikes that require a custom fit. The main difference from a standard chain is the ability to fine-tune the chain length for a better fit on the bike.
Half link chains offer greater adjustability in chain length, allowing for more precise tensioning and alignment on BMX bikes. This can help improve overall performance and reduce the risk of chain slippage during tricks and jumps. Additionally, half link chains are often more durable and can provide a smoother and more efficient ride compared to traditional full link chains.
No, you can just cut your chain with a chain breaker or just take it to a shop and they will do it for you.
Go to bike shop or wolyworld and buy a link remover.
Half links only come in two sizes, 1/8" and 3/32". Which one you need is determined by which chain you're running. Depending on which sprocket you had before a half link may not be enough. On a bmx just make it fit, they tend to slack by half an inch to adjust while peddling back since they don not lock. Meassure until nearest like possible.
they keep your chain tight
inox or chain lube from a bike shop
No. Some BMX chainrings have the same 4/5 bolt pattern as road bikes, but most use another method of attachment to the crank. If it is a 4/5 bolt chainring you first have to measure the bolt circle diameter to see how that fits. I'll post a link on that. Next is the thickness of the chain rings. BMXes are single-speed and use a thicker chain. Most road bikes have external gears and need a thinner, more flexible chain to work. I'm not sure if a road bike chain will fit on a BMX chainring. (Unless it's a single-speed road bike of course. Then you can run a BMX-style chain and all can be made to work.)
they can range from 46teeth on a chain wheel all the way down yo a 22tooth chain wheel.
It depends on the length of the chainstays on your frame.
A chain is a chain, it hasn't got any gears in it. But if you run it across a pair of sprockets you can create a gearing ratio.
A crank (or a crankset) is the thing that sits in the middle of the bicycle, has the chain on it and have the pedals attached to it.