yater

Which size and model do I need? I'm not looking at the bike right now but need to order one...I'm sick of my current deore (junk) ruining my ride

seely

I almost guarantee its not the derailleur, its either worn components (cable, housing, chain and chainrings?) or poor adjustment. All a front derailleur does, no matter what level, is mash the chain one way or the other. Its probably the simplest and least sophisticated piece of the drivetrain and the most misunderstood. I have used Deore, XT, LX, XTR, Veloce, Mirage, Centaur, 105, RSX100, Ultegra, 600, Dura-Ace, etc, etc and they all work the same. I can't tell a difference that I can attribute to the derailleur. You'd be surprised how much difference a quality chainring makes in your shifting, and new cables and housing with a proper derailleur setup.

yater

I'm replacing the entire drivetrain....a piece at a time. I'm adjusting this derailleur every couple of rides and it cost me a DNF in a time trial today. I want it OFF THE BIKE.

seely

If you're adjusting it every couple rides, you must not doing something right. I'd recommend going through the Park Tools setup guide step by step. Not to brag, but I set a derailleur once and don't touch it for 2-3 seasons typically (other than cable tension tweaks), front or rear. Once the limits are set you should never have to touch the screws again, and on the front derailleur the only other adjustments are cage angle, cage height and cable tension. Like I said, chainrings make a lot more difference than a derailleur, and if you have any excess friction in the cable/housing, it will never shift right, no matter what you do. Heck, even where you clamp the cable can make a difference. If you want to spend the money, go ahead, but it sounds like a setup issue to me, and if you can't setup a Deore derailleur an XT won't work any better, to put it bluntly.

yater

So how about the size?

seely

You have to know size, pull and swing. The clamp is most likely a 34.9, but I don't know if its TP/BS BP/TS, or what.