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Discussion Starter · #1 · (Edited)
I'm trying to figure what the difference would be between a Ritchey 110mm - 84deg. and a 73 deg. flipped for rise. I thought it would be angle, sine x length. I think I'm missing something.
After having a disksectomy of my L-5 S-1 in 2002 I'm having back problems again, but not to the same degree. I think my 4" drop from saddle to bar top is a little much for my 47yo. spine. I will hate the looks of a stem with such an uprise but the steerer is cut for only 1" of spacers.
 

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la dolce vita
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If you can't change the facts, change how you feel about them. Maybe a stem that points a little north isn't a bad thing.
 

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duh...
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Mootsie said:
If you can't change the facts, change how you feel about them. Maybe a stem that points a little north isn't a bad thing.


cheaper than the alternative of a new fork
 

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Trigonometry tables, if you want to be super-exact.

See? High-school math was useful after all. :)
.
 

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info..

I use good old trig. The rise of a 96 degree stem with a 73 degree head tube is sin23 x 110 = 43mm. The rise of a 107 degree stem 61.5mm, so the difference is 18.5cm.

You also need to consider the horizontal length, which is only 101mm for the 96 degree stem and 91mm for the 107 degree.
 

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High Gear said:
I'm trying to figure what the difference would be between a Ritchey 110mm - 84deg. and a 73 deg. flipped for rise. I thought it would be angle, sine x length. I think I'm missing something.
After having a disksectomy of my L-5 S-1 in 2002 I'm having back problems again, but not to the same degree. I think my 4" drop from saddle to bar top is a little much for my 47yo. spine. I will hate the looks of a stem with such an uprise but the steerer is cut for only 1" of spacers.
A four-inch drop was too much for my spine when it was 10 years old. FWIW, raising the bars so they're level with the saddle cured ALL my back issues four or five years ago, and it didn't make me any slower, maybe because I was already slow enough that aero drag was only a theory. Next to being able to ride pain-free, the looks of the bike don't even register with me. Anybody who doesn't like it can look the other way.
 

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Discussion Starter · #10 ·
orange_bikes said:
The chart above is good, but I find this online calculator to be most useful.

http://alex.phred.org/stemchart/Default.aspx
I found this stem calculator to be inacurate for some reason. I should be getting a difference of .82" of stem rise change going from a 6 deg. to a 17deg. stem in a 110mm length. This is giving me only .748".
 

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Discussion Starter · #11 ·
High Gear said:
I'm trying to figure what the difference would be between a Ritchey 110mm - 84deg. and a 73 deg. flipped for rise. I thought it would be angle, sine x length. I think I'm missing something.
After having a disksectomy of my L-5 S-1 in 2002 I'm having back problems again, but not to the same degree. I think my 4" drop from saddle to bar top is a little much for my 47yo. spine. I will hate the looks of a stem with such an uprise but the steerer is cut for only 1" of spacers.

I was right. It is angle - sine. X length. I found the online angle calculator to work great and it even will give you a reach change (little b) when going from one stem angle to another.
http://www.csgnetwork.com/righttricalc.html

Just plug in your stem angle in "Angle A or B". Use only degrees from horazontal.
Plug in your stem length in "Side c" and hit calculate. Your done. "Side a" will be your stem rise and "Side b" will be your reach.
 
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