I'm a little bit confused about stem angles and could use some clarification.

I currentlty have an ITM Visia stem with 80° angle- that puts it almost horizontal on my bike. I like horizontal.

I'm considering getting an FSA stem and they state their stems are angled 6°. Does this mean that the it's really 84° in comparison to the ITM (90° - 6° = 84°?) If so, then the FSA stem will be angled up slightly, correct? I don't want that.

Why can't all the manufactures use the same reference point? It would be less confusing.

One of the problems is that not all head tube angles are the same.

90* is the reference point, however as you have noticed a 0 degree or a 90 degree stem(same thing) may not put you at a horizonal position because the steerer on the fork is at an angle as well.

Also, all stems(other than quill) can be flipped. So that 84* stem is also a 96* stem aka +/- 6 degrees. If you want another stem and want it to be oriented the same way as your current stem, you will need the same angle (80*).

So the question is...Why are you getting another stem if you like the one you have?

that has nothing to do with it.

OP you understand how it works correctly.

As far as the standards go with quill stems 80deg, 90deg etc makes sense. With most threadless that doesn't cause they can be flipped. An 80 is usually an 80 or 100. Therefore it makes more sense to quote the angle as +/- 10deg or just 10deg.

Why are there english and italian bottom brackets? to strip threads.

Most frames have a 73 degree head tube, which means that horizontal would be a 17 degree stem.
What's worse than manufacturers not agreeing on 10 degree/80 degree , 84 degree/6 degree is that some internet web sellers of stems (cough*PBK*cough) don't state the stem angles in the catalogs, just the length.

Regardless, you should not be picking a stem angle based on looks.

It has everything to do with it if you are looking to have the relative stem angle at 0 degrees and your Steerer is at an angle as well. You have to factor this in to get the relative angle you are looking for.

True, but the OP was just complaining than some call is an 84 while others call it a 6. (S)he already understands that it is relative to the head tube angle.

I always figured the way they measured it changed when they went to threadless. I'm not positive, but I think all quill stems were original leballed by actual angles. It sounds weird to label a stem an 84/96, so they just called it 6 so you could decide +/-

The ITM Visia stem is one that came with the bike. It's a 90mm and I'm looking for a 110mm.
I was considering the FSA Carbon Pro stem- decent price and looks like carbon to match the rest of the bike, but I'm concerened about the angle. I wouldn't mind even if it were to angle down a bit, but it seems that w/ the 6° angle it will always angle up. I guess that's why Orbea specs ITM.

Thanks to everyone for confirming my assumptions here!

This chart from Habanero gets posted here and there and has always worked for me in figuring out stem angle and virtual stem length/reach:



And text from the site (https://www.habcycles.com/fitting.html):

"Note: The above method of measuring stems is only one of a plethora of methods employed - but is probably the most popular one currently. Some manufacturers measure stems in "degrees above horizontal" (common on road bikes, and assuming ~72-3 degree head tube), "degrees from 90 degrees", etc. If in doubt, print out the chart, and use it to guesstimate your stem's "degrees above horizontal" value by aligning the bottom of the chart with a horizontal surface and sighting the stem extension against the extension lines on the chart. You'll usually be pretty close in estimating your head tube angle at 73 degrees (road) or 71 degrees (MTB). So, to arrive at "stem angle", add the head tube angle to the "extension angle" from the chart and you'll have a number that most bike shops can use."