PROBLEM: You've been riding with the same chain for ages, and wonder if it's time for a replacement.

SOLUTION: There are several ways to ID a worn chain. Here's the one we like best.

First, shift onto the large chainring. Kneel at the right side of the bike.

Using a 12-inch ruler, hold it along the bottom run of chain (between the lower derailleur pulley and chainring). Put the ruler's first mark on the center of any link pin.

Then look at the 12-inch mark. On a new chain, that mark will also be on the center of a pin. If the mark falls short of a pin, the chain is somewhat worn. If it's 1/8 inch or more short, it's so worn that it should be replaced.

Remember, milking more miles out of a shot chain is a sure way to make the chainrings and cogs wear faster. That gets expensive.