I think my all-time favorite derailleur for a mountain bike is the M950 series XTR derailleur. It's just, well, it's just a great looking mountain bike derailleur. Rugged and tough looking. One of the neatest features about it, though, is it's spring tension adjustment. Theres a little Phillips head screw that increases spring tension in the main spring. I say increase because new out of the tension is set at the lowest setting. This ability to adjust the spring tension is nice when dealing with cables that are a big mucky and are slowing the shift to smaller cogs. A quick turn of the screw, increased spring tension and bingo!, snappy shifts once again.
The other benefit of that screw is on big tall bikes like mine. When you are running a big tall bike, there is more cable housing than smaller ones. More cable housing, more friction. Adjusting the derailleur spring to higher tension overcomes the friction and you've got nice snappy, happy shifting!
There's that spring tension adjustment.
Yeah, I got a few spares. When you like something, well sometimes you go a little overboard.
And as a quick "What's In The Stand," there's that Potts CCR getting it's parts back on and a Salsa Fargo. Sweet bikes - both of them.
(What's playing: Dave Alvin I Am Bewildered)