Originally Posted by
shagohod
well what about the chain slipping? i'm a little confused. sorry.
the chain is brand new, i therw the old one out after i replaced it
Okay, okay...forget about the chain/cassette thing until you figure out if you're cassette is compatible with your derailleur. Adjust the tension screw(it's the lonely one up top that presses against the frame). It's adjustment determines if your RD can shift to the largest cog in back. If your RD cage or pulley is hitting the cogs, you'll need to turn the angle screw in until it allows the chain and cage to clear the largest cog without interference. If you get this set properly and your current RD is indeed compatible, I am pretty sure the chain slip will be cured. You may need to adjust the limit screws to dial everything back in. I hope this helps.