When I ride up a hill the locking gear inside the 7 gear rear wheel jumps a gear. I removed the rear wheel and chain sprocket. I tried using a wrench on each side to remove the sprocket. Do I need a thin open end wrench on the inside nut to remove the chain sprocket? What size?
Cycling - Schwinn
Answers & Comments
Before you go tearing everything apart it might help to understand how multi-speed derailleur shifting systems work.
Derailleur Adjustment: (likely cause of your problem)
http://sheldonbrown.com/derailer-adjustment.html
Shifting:
http://www.sheldonbrown.com/gears.html
Cassettes and Freehubs:
http://sheldonbrown.com/k7.html
Chains: (which also covers worn gear teeth, another possible cause)
http://sheldonbrown.com/chains.html
Of course everything requires special tools and procedures.
http://www.parktool.com/blog/repair-help
http://www.parktool.com/blog/repair-help/categories/cassette-and-freewheel-service
http://www.parktool.com/blog/repair-help/categories/derailleur-systems
Have fun.