Chain slips a tooth

[Guest]

Hi Alex,
After a year of not using my ATB, I decided to clean the dust off it and go for a ride. After an afternoon of cleaning, adjusting the shifters & breaks I took it out for a spin, but every time I wanted to put some extra pressure on the pedals, the chain slipped a tooth or two on my back sprocket, no matter what gear. What can I do to fix it? (it has a Shimano Deore derailer from 2005).
Jelmer

[Alex Ramon]

Hi Jelmer,
Sounds like you have a stiff chain link. Run the chain backwards through the rear derailer and watch closely as the chain runs over the guide pulleys. If you see the chain jump every rotation, grab the two links at that spot and twist them back and forth a little in both directions. That should loosen it up again and solve your problem.
This video might help:<br />
http://bikeride.com/stiff-chain-link/
However, if you don't have a stiff link, it could be a worn out chain. Take it to your local shop and ask them to check the chain wear. Or, you can watch <a href="http://bikeride.com/chain-wear/">this video</a> to check the wear yourself.