Originally Posted by
Corben
130mm you say? well then my rear derailleur ( SHIMANO CLARIS RD-2400GS BLACK ) according to google is a 8 speed. should I pick up a 8 speed cassette while I'm at it?
I wouldn't, your shifters are 7 speed, if you go to 8 speed cassette you'll have to change the shifters to 8 speed.