Dirty bike chains lead to substandard performance. Dirty chains stick, slip and have difficulty shifting. There are few things worse than a failing chain on a long mountain climb. Cleaning your bike chain is possible on or off the bike. Cleaning on the bike is prudent for preventative maintenance but removing the chain is necessary when dirt and grime has worked into difficult to reach places.
Obtain two glass jars with watertight lids, a funnel with 150mm (6 inch) diameter, clean rags, kerosene or lighting paraffin.
Remove the bicycle chain using a chain breaker or pry off the master link. Place the chain in a first jar, shake it down and cover with the kerosene. Replace the lid.
Dump the contents of the first jar into the funnel. Allow to drain a few minutes.
Meanwhile wipe out the first jar and rinse into the funnel with clean kerosene. Replace the chain in the first jar, add kerosene and soak and shake or swirl again.
Pour the kerosene from the first jar into the second through the filter, seal the second jar and store for re-use.
Clean out the first jar, seal and store.