Originally Posted by
Jdubstheman
Thanks all again. By replacing my chain (was confirmed stretched by my Park measuring tool) with a new Shimano chain my shifting is actually back to perfect! No new cassette required! However I am toying with taking the cassette up to a 12-30. Is that doable within the specs of the 7700 group I have?
Chains don't "stretch", they Wear, at the pin/bushing interfaces.
And your Derailleur probably won't work with a 30 t 1st gear cassette. Is the Der. a "short cage"? if so, a 27 is just about max. The front Chainring combo info will also be required for anyone to make the call for you here...