So I just picked up my Tri bike from the LBS where I had the cables put on. While I could not be happier with the bike, the fit is, of course, way off. I asked when installing the fork that they leave plenty of tube to allow for fitting and this they did. While the current stem on the bike is a 120mm 6 degree rise stem, I would like to put a ritchey adjustable stem on this bike to get the fit better (I already own this adj stem). The LBS said that was fine but said not to plan to use the adj stem long term. Other than the weight and the fact that the stem can, I suppose, wear out and fall during a ride (given how the Ritchey is constructed I got a hard time believing this could happen in my lifetime), what is the downside of the adj stem? I have a hard time believing that I can get the range of possibilities with fixed stems the way I can with the adj stem, thus allowing the best customization of fit.

Other than weight, there should be no problems with using the adjustable stem long term. I suppose you could wear out the adjustment interface if you changed the angle every day but I presume you will find the setting you prefer and leave it there. Once you get the desired configuration you may be able to find a matching and lighter fixed stem but there is no reason to be compelled to do so.

Yeah, this is what I figured, the adjustment mechanism in the Ritchey I have is pretty bulletproof. But I also started really looking and there are a helluva lot more stem lengths/angles than I initially believed.

The only real objection to adjustable stems is weight. Some also have rigidity issues at the hinge, allowing some unwanted play, though better made ones are fine. The main reason not to simply leave it on is that's it's deemed uncool, and you might draw comments from folks who think they're better than you are.

Leave the adjustable on as long as possible until you're sure you've dialed in your position, then either replace it or don't depending on your mood.

Naw, just tighten properly, check on it occasionally and you're fine. There is no additional wear on the components involved.

FBinNY hit it on the nose, the mechanics aren't the issue, you're just about to do something ludicrously uncool. I mean, an adjustable stem on a tri bike? You'll be the laughing stock for sure, even more so than the people who can't mount effectively.

"ludicrously uncool" Must avoid at all possibilities....

I think what I'll do is to put the adj stem on there until I figure out what length/angle works best then see if I can get a fixed stem for the bike in some fashionable high end, super space age material...