Hopefully someone can answer this question quickly for me. I'm wondering which stem degree + clamp height will WHEN FLIPPED allow for greater height. I want a flipped stem (negative degree) but want to be as up right from that flipped stem as possible between these two choices:

stem 1: Size: ± 6° x 90mm (w/ stack height of 35mm)
stem 2: Size: ± 10° x 90mm (w/ stack height of 36mm)

Does the stack height even make a difference in the equation?

Thanks for any incite.

The 6 should be higher when flipped, even with the stack height.

i want to help, but i am not sure what you are asking?

can't you use math or something? like Pythagorean theorem?

or SOH CAH TOA

Assuming the fork is already cut, the stack height will tell you what spacers you will need.

By negative degree do you mean the stem is pointing downward from the head tube angle (more parallel to the ground than rising)? The -10* angle is lower than -6*

Thanks all. I wasn't sure how the stack height would factor into the 'equation'. It's too bad..was really looking into buying the thomson elite x2 stem to match my seatpost. I hope it's evident that I'm not pursuing a major in mathematics or engineering.

Quote:

Originally Posted by mx_599

i want to help, but i am not sure what you are asking?

can't you use math or something? like Pythagorean theorem?

or SOH CAH TOA

Do I detect a bit of smug'ness? (I don't really care so no need to answer)

no not at all. i was seriously trying to help and thought i knew what you wanted until i read the rest of your post and then i didn't really know which way you wanted to run your stem and i am still confused by the other poster who said 6 degree is higher...oh well, maybe it's cause i am falling asleep

Take stack height out of the equation. Stem #2 will allow for more difference in bar height between flipped and unflipped.
A 17 degree stem will show even more diff when flipped.
A 90 or a zero degree stem shows no change when flipped.

so then why is this true??

basic trig. Given right triangles and finding the 3rd angle, use the law of sines to find the shortest side (the drop). The 6 degree stem will have a drop of 9mm while the 10 degree stem will have a drop of 15mm. Subtract 1mm from the 10 degree to compensate for the stack height, and the 6 degree stem is still 5mm higher.

Now this doesn't account for the head tube angle, in which case you would have to rotate the entire equasion about 15-20 degrees to know the actual vertical drop. But that doesn't change which is higher, just by how much it is higher, and even that would be a small variance.

I sometimes wish my brain relied more on the left side of itself.

nevermind.

i thought they were referring to it after it was flipped. the 6 would not be higher after flipped.

honestly, i don't even know what way the OP wanted it.

still don't see this:
so then why is this true??

what you described before was it angled down...

You asked for it. It's actually more important that both sides of the brain communicate with each other. When they comunicate with each other, they find more ways of remembering things allowing for an easier recall of information. Besides, it's not so much knowing the information as it is knowing where to get it. I haven't taken a math course since 1999, but I know how to google "finding sides given angles" and apply the equasion I find.

This has been brought to you by a school teacher who majored in music and excelled in mathematics, but can't remember where he left his shoes last night.

Good point. My understanding of the term "flipped" is that it means the stems are angled down (whenever someone says to flip the stem, it's because the shop sold it pointing up and the suggestion is to point it down to be more aero). If the OP meant the question for if the stems are angled up, the answer would indeed need to be reversed.

Indeed. I probably should have worded that a bit different. I always enjoyed my biology and psycology classes (still taking courses). I just haven't/don't enjoy learning mathematics past the algebra level.

As for the original post: I meant when the stem is angled down. When someone says to 'flip it', usually they're hinting that the stem should be angled to the negative degree/down. Seems like the wording in the first post is coherent enough?

I've been trying to find a road stem too with a steep angle, but they seem to be hard to find. Why is that the case?

i thought i was going crazy...we were just thinking of it differently. plus it was a confusing original post.

*note to self, stay away from confusing original posts*

Yes I understood what he meant by "flipped" but I can see how some people would think it meant the opposite. Technically speaking, the correct way is down, so some might see up as "flipped". But answering the confusing posts is what makes it fun.

This shouldn't be too hard. For a threadless system, try to find a touring stem (like +25) and flip it for a downward angle. For quill, find a track stem for a steep downward engle, and a touring stem for a steep upward angle.

here are some parts i struggled with:

1. Hopefully someone can answer this question quickly for me. (at 12:31 in the morning)
2. ...but want to be as up right from that flipped stem
3. Thanks for any incite.

Ah yes, I do wonder why he wants to be as upright as possible if the stem is flipped down. I just figured it was an OCP thing. He wanted speed because he wants to make a purchase soon. I decided not to give him any "incite" since I don't know what that is. I gave him insight instead

Incite means: to give incentive for action. I guess insight would have worked all the same. And yes, I was thinking of ordering a stem and hoping to have it by Tuesday with 2nd-Air, good assumption urbanknight. The reason I want the stem flipped - but want to be as upright as possible is one count of that OCP factor and two counts of my feelings towards how the bike feels to me/steers. I 'think' it feels better when flipped.. although it could be all in my head.

Fair enough. You know, a stem is effectively shorter when it is up as well, so that might account for the feel. A longer stem should just make it higher, which does effect the handling a little as well, but so does a higher bar in either case.

Thanks for the definition of incite, I didn't know that one.

I've actually thought about ordering a 0 degree stem in 100mm (thomson x4) instead of a 5/6/or 7 degree stem in 90mm. There's still a lot of trial and error left to do. I just recently understood the concept and application of a handlebars reach and drop. Replacing my FSA RD-250 with an Easton EA70 (special cost $35 shipped from competitivecyclist.com). I can now angle the bars down a little more and mount the shifters further up/toward me a bit to help _not_ be so stretched out. Appreciate all the info.

No math required https://www.habcycles.com/fitting.html

I actually had that .jpg saved from awhile back. I wasn't sure about stack height and if it made a difference or not...wanted to be sure. Thanks, definitely a great thing to make reference to.