The chain is a very important part of the bike since if you get the wrong size or length you risk to fall off your bike.

There are two main izes available on the market: 3/32” and 1/8”. The first is supposed to be used for road bike with speed, the latter for single-speed, bmx and track.

For you fixed gear I would recommend a 1/8” because is thicker and safer especially if you are going to use the bike w/o brakes. therefore if you buy a 1/8” be sure you have a 1/8 cog and chainring…not all the crankset come in 1/8”…for instance the Sugino RD is a 3/32 but most of the sellers pass it off a track crankset but is not really also because have some lips for an additional smaller chainring..

Brand to search for:

My favorite brand is KMC, they do lots of model but the basic model Z410 (tha same used or BMX) is good enough, cheap, and comes with the link.

I don’t particularly like the colored chains because the color scratches away in few weeks. Silver is the best to me.  

Choose a chain with less links. If you dont’t have speeds or tensioners 112 or less are good — unless you are using a 60T chainring with a 24T cog!.—

Before you buy

Be sure that your chainring and cog have the same thickness (not mandatory but recommended.) You cannot use a 3/32” chain on a 1/8” chainring (but you can do it viceversa but with the risk the chain could go off the ring…avoid!)

How to install

You need a simple tool called Chain Tool, duh.
I use a Park Tool CT-3 and i like it so far. You can also buy its spare pins in case you brake them.