If you want to try a different stem:

1. Have a good relationship with a good LBS in the area. This applies for pretty much anyone, in general, so you always have a place to go.

I'd term "Good relationship" as you are friendly, buy stuff semi-regularly (focus on smaller high margin things, not looking at blow out bikes where the shop is just trying to recoup costs), drop in every now and then, and if they have group rides, you go on a couple of them.

2. Once you have a good relationship with the shop, ask about stems. If they're really nice they may let you look at their (non-priced) catalog, or give you a run down on what they can get.

3. Ask to borrow 3-4-5 or more stems, lengths varying by 1-3 cm from your current stem, different angles, even different materials. Any semi-established shop will have a number of take-off stems. This is where you'll start learning of clamp diameters and stem angles. Let the LBS show you - it's easy to see what a 73 vs 80 vs 90 deg stem is when you're holding them in your hands.

4. Choose a size/angle and order/buy the stem you want from the LBS.

5. If you decide to repeat the process, now you know what you need to do. Buy the stem where ever.

The last stem I bought was for the tandem. I knew exactly what size/angle I wanted but not the brand/material/etc, decided I wanted to use this opportunity to help build my relationship with the local shop, and paid full retail on the stem (at my insistence). I believe that the shop made $60 on me, which I thought was reasonable, minus shipping, the time it took to talk about stems (not much), the time they let me tap away at their computer to find the stem (probably 15 minutes), and the resulting time of me looking at other things (another 15-30 minutes). I figure $65/hour is about what they need/should make on me.

cdr