How To Repair Derailleur. Replace derailleur when this play becomes significant. The cost of labor for bike mechanics varies depending on your area but replacing a rear derailleur on a mountain bike shouldnt take more than a half hour for a bike repair professional.
A customers 7 year old kid could have kicked the derailleur on the showroom floor. Heres a basic overview for first timers. One of the hardest working but rarely appreciated parts of the overall equation.
If you can force the derailleur to move with your hand its very likely to can repair it just by pouring sufficient oil on it and working it backwards and forwards for a while.
The cable attached to the front derailleur should be as tight as possible without moving the front derailleur. My local shop charges about 30 for the labor plus the cost of whatever parts you decide on. The cable attached to the front derailleur should be as tight as possible without moving the front derailleur. Replace derailleur when this play becomes significant.
