I have 2006 Centaur

[dphoenix]

If I upgrade my rear derailleur to 08 Record will I notice a performance difference or is it just lighter than the Centaur derailleur?

[smokva]

You'll climb faster because your wallet will be lighter
Except that i don't think you'll notice anything.

[natedg200202]

If there is significant wear or damage to your current Centaur, then it might benefit your shifting performance to replace. If your rear derailleur is in good shape, I doubt it will make a difference besides a placebo effect.

I have heard it said that the aluminum cage rear derailleur is actually stiffer than the carbon fiber cage, but I don't know if that is based on fact.

[dphoenix]

Centaur carbon thought the 08 Record derailleur would go better with the new shifters. My centaur derailleur shifts fine, I wouldn't buy the Record unless it performed better.

[wankski]

derailleur is a spring with jockey wheels - that is it. jeez, slap record on it and a rediculous price and "they will come"

[ti-triodes]

You won't feel any difference in shifting. Lose 1/8 of a pound and you've more than made up for the weight difference,