Hi! I'm considering switching out my bike's threadless stem, a FSA OS-190. Google says it's got a stem angle of 84 96 degrees. Now, I don't understand...how can the stem have two angles!?

While I'm at it : What are common angles/measurements of stems considered desireable for touring/commuting?

Thanks! I'm somewhat new to the bike world, but I'm quite avid!

It's 6 degrees from perpendicular (90) and can be flipped either up (90 + 6 = 96) or down (90 - 6 = 84). The 6 degree stem seems to be the most common angle for commuting, but I am sure you can get higher angle stems.

Why do you want to switch it?

My take on stems for touring is that you should try and set up your bike for all-day comfort. The stem can raise or lower your bars, and it can also extend or shorten your reach to the bars (from the saddle.) I like the top of my bars level with or only slightly lower than the top of my saddle. I've found this lessens hand soreness/numbness. I have my seatpost pulled out quite a ways for my long legs, so I like a stem with some rise to it, to match. I can't tell you what gauge I use to determine how far I like the reach from the saddle to the bars. I just ride and play with it until I find a setup that feels right. You can do this by sliding the saddle forwards or backwards, and if you can't get it right you can also try a different stem with less or more reach.

The reach on my LHT seems rather long, so I have a stem with lots of rise and not much reach.

I bought a few stems (Ebay helped) before I found the one that seemed right. I kept them and they were usefull in setting up my next bike. I'll probably keep them, in case I or one of my family gets a new bike in the future. It's nice to have a few different models to try when you're setting things up. Even if you don't settle on one, they can help steer you to a purchase that will work.

aah! I see! Thanks for explaining the two numbers, caloso!

The confusing thing for me is when you start to consider that the headtube is not straight up and down; typically, it's at 15-17 degrees from vertical. So, you may see stems labeled as 17 or 73 degrees. When installed, they allow you to have a stem that's more or less parallel to the ground.