Rear derailleur to replace Shimano Alivio

chasingspring

Hi

I'm trying to buy a rear derailleur for the first time (because I want to fit it myself) but am a little overwhelmed by the decision of what to buy - hope someone can help!

Details:
Specialised Globe (hybrd) currently with a Shimano Alivio rear derailleur and a Hyperdrive front.
My rear cassette is 8-speed

So my questions are how do I decide what would be compatible with my bike, what are my options, and does anyone have a recommendation?
I'd like to go for something a little better than the Alivio (I'm no concerned about the weight of the component, but more in terms of quality, shift-speed etc).

Thanks!

The Rookie

Anything Shimano and MTB, Deore would be the obvious choice, anything marked 8 or 9 speed will work.

CitizenLee

Deore M591 is probably best bet value, but you can get SLX M662 for only a fiver more, which is still a great buy and probably what I'd go for.

Chain Reaction have both on offer right now.

chasingspring

Thanks CitizenLee, I'll have a look at those!

The Rookie, I was looking at Shimano but wasn't sure which ones would be compatible with what and the shop descriptions weren't too helpful

fallenagain

If you have a triple in front, you should buy a long cage one (SGS), Also, do not get a "Rapid rise" one, they may be cheap, but they move the chain the wrong way.

chasingspring

OK, noted!

The Rookie

A Rapid Rise works the other way round to normal, but works just fine, some prefer them and I have one on my MTB and the wife has one on hers.