Hi BikeForums!

I've been commuting on a second hand raleigh for a few months now, and have recently taken it to pieces to clean everything up and get it rolling a bit smoother.

Having done so, I replaced the chain and rear derailleur as they were rusty and now have a problem with my gears slipping when I pedal hard on the smaller sprockets of the cassette...

I have taken a few snaps of it and wanted to know if I should consider replacing? I've spent a while adjusting my old and new rear derailleur to get the slipping to stop to see if it was the fact that i changed the derailleur, and no matter the tension of the cable, or old/new derailleur, the problem does not go away.

I've done some digging on the net and found that its generally good practice to replace a cassette that has had a worn chain on it for quite some time (which I have used every weekday for the past 6-7months of ~4miles per day)

Thanks,
Austin