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I have an old (15 years?) Giant bike with the Shimano 70GS derailleur. It has been so long since I rode the Giant that I cannot remember how to actually adjust or even work the shift properly. The biggest problem is in the adjustment; I can figure out the shifting part -- if I can remember my right from my left.

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  • Jim Allen Oct 12, 2010

    Many thanks. It's been at least four years since I rode it and now I have the need again. Good advice.

  • Jim Allen Oct 12, 2010

    Yes, it was very helpful. The mind is a terrible thing to lose.



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If the derailleur was working alright when it was last used it probably only needs to be oiled rather than adjusted. The rear derailleur moves in, towards the bike, and out when you move the gear lever. There's a screw that acts as a stop to prevent it moving out too far. If you look at it and move the derailleur by hand you'll see it. This can be adjusted if it needs to be. To oil the derailleur, oil the hinge on which it moves in and out. Oil the teeth and the chain. The cables may be seized and need replacing. To check you can disconnect them by loosening the nut and bolt that connects them to the derailleur and try moving the gear levers or just pushing and pulling the cable wire through the core. If they move easily enough it's worth pulling them out and oiling them as they probably have some rust on them. There's very little else to getting them working again. The front derailleur will also need oiling and the wheel bearings on both wheels will need greasing.

Posted on Oct 12, 2010


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