Most chain tools look and function pretty similarly to one another. Most look almost like a miniature vise, with some kind of "cradle" to position the chain links, and a threaded driver and "T" handle with a pin at the end. You position the chain into the cradle, line up the pin to the rivet, turn the "T" handle, and drive the pin through the chain -- pushing out the rivet. To reconnect the chain, you turn it around and use a similar process to drive the rivet back into place.
Let's take a look at a few in my collection:
|This is a vintage SunTour chain tool. It's a pretty nice one with a couple of features that make it unique.|
|For the sake of size comparison . . .|
|These were made by Gian Robert - which was maybe better known for making fairly inexpensive derailleurs. There is another tool, the VAR 303, which is almost identical. A lot of old-school bike mechanics have good memories of these.|
|A simple pliers-type tool, but the jaws are narrow and shaped to get right in between the links in a bike chain. Position those around the ends of the master link, squeeze, and the link can be separated easily.|
And before you go putting a used chain back on the bike, it's a good idea to make sure it isn't worn or "stretched." There are lots of different chain gauge tools out there - and some people just use a ruler. Here what I use:
|The Park chain checker. It can tell you pretty quickly if a chain is "passa" or "non passa." It's a good thing to keep in the tool box.|