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...the current crop of mechanics are all schooled in the Shimano Official Corporate Line, which states, "Thou shalt change the chain every 1.000 miles, and the cassette cogset every other chain swap." Which is a little bit on the anal side for most practical users who do not ride in severe conditions.

It's difficult to tell whether yoiu need to change out your cogs (or freewheel if your bike is that old and has one), without actually looking at it.

But by far your best course of action as a poor person who rides a bike is to buy yourself a KMC 6-8 speed chain (they are cheapest online, but you may be in a hurry), a tool to push out the pin to shorten the chain to the length you require 9match it to the old one), and then to see how well your bike works.

If you get a lot of skipping and jumping around, with poor shifting performance, you need to replace the cogs (or freewheel).


If you rode this chain long enough for it to break, there's a very good chance your cogs are worn too. Which is why the shop is telling you this and why it's that much to have them do it.