Stem degree help
Moderator: robbosmans
Guys,
I'm buying a new stem (zipp) and the one it's replacing is a deda, on the deda it says 82 degree, I want the same or slight lower profile for the new one but the ones iv seen online say 17 degree's or 6 degrees, I don't understand why the degrees are so different?
Can anyone help on what I should be buying in the zipp stems?
I'm buying a new stem (zipp) and the one it's replacing is a deda, on the deda it says 82 degree, I want the same or slight lower profile for the new one but the ones iv seen online say 17 degree's or 6 degrees, I don't understand why the degrees are so different?
Can anyone help on what I should be buying in the zipp stems?
Last edited by Wonderman on Mon Aug 31, 2015 4:39 pm, edited 1 time in total.
Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓ Broad Selection ✓ Worldwide Delivery ✓
www.starbike.com
82 degrees means -8 degrees. Deda counts from 90 degrees. Other brands call 90 degrees 0 degree.
That means -6 degrees is a more upright position compared to 82 degrees.
That means -6 degrees is a more upright position compared to 82 degrees.
Last edited by fEichert on Mon Aug 31, 2015 2:23 pm, edited 1 time in total.
i think you subtract 90 degree from the 82 and you get 8 degrees. 6 degrees is typical, like an Enve stem. 17 degree is extreme (up or down depending on how you orient the stem).
- Factor Ostro VAM Disc
- Factor LS Disc
- Specialized Aethos Disc
- Sturdy Ti Allroad Disc
- Guru Praemio R Disc
- Factor LS Disc
- Specialized Aethos Disc
- Sturdy Ti Allroad Disc
- Guru Praemio R Disc
- Lightweenie
- Posts: 199
- Joined: Sun Aug 03, 2014 1:00 pm
It depends on how the angle is measured. 82 degrees is "equivalent" to 8 degrees, 17 to 73 and 6 to 84 (they always sum up to 90).
-
- in the industry
- Posts: 429
- Joined: Fri Dec 07, 2012 8:34 pm
- Location: CO
Your Deda is an 82 degree (or 8 degree depending how you look at it), therefore neither of those Zipp stems will be the same angle.
you could get the 6 degree and drop it a few millimeters
find a different 8 degree stem
or just deal with a slightly different position
using basic geometric principals (triangles and sine, cosine, tangent) you can calculate the difference in position between differing stem angles
For Example: assuming a 100mm stem the effective position for each angle is as follows
Reach: (stem length)*cos(angle)
Drop: (stem length)*sin(angle)
6 degree:
Reach: 99.45 mm
Drop: 10.45 mm
8 degree
Reach: 99.03 mm
Drop: 13.92 mm
17 Degree:
Reach: 95.63
Drop: 29.24 mm
This is all relative with assumptions taken into account so don't quote me on these numbers, but its a simple enough method to figure out which stem to get.
you could get the 6 degree and drop it a few millimeters
find a different 8 degree stem
or just deal with a slightly different position
using basic geometric principals (triangles and sine, cosine, tangent) you can calculate the difference in position between differing stem angles
For Example: assuming a 100mm stem the effective position for each angle is as follows
Reach: (stem length)*cos(angle)
Drop: (stem length)*sin(angle)
6 degree:
Reach: 99.45 mm
Drop: 10.45 mm
8 degree
Reach: 99.03 mm
Drop: 13.92 mm
17 Degree:
Reach: 95.63
Drop: 29.24 mm
This is all relative with assumptions taken into account so don't quote me on these numbers, but its a simple enough method to figure out which stem to get.
- ALAN Carbon+
- Posts: 294
- Joined: Mon Dec 26, 2005 9:21 am
- Location: Canberra, Australia
This might help visualizing the different height/reach of the two stems http://yojimg.net/bike/web_tools/stem.php
Sent from my 0PJA10 using Tapatalk
Sent from my 0PJA10 using Tapatalk
kode54 wrote:i think you subtract 90 degree from the 82 and you get 8 degrees. 6 degrees is typical, like an Enve stem. 17 degree is extreme (up or down depending on how you orient the stem).
I would hardly call 17 degrees extreme. It results in a stem parallel to the ground, which is how nearly all quill stems were made. It's also arguably the most aesthetic.
My favorite components are the ones I never have to think about.
jpanspac wrote:kode54 wrote:i think you subtract 90 degree from the 82 and you get 8 degrees. 6 degrees is typical, like an Enve stem. 17 degree is extreme (up or down depending on how you orient the stem).
I would hardly call 17 degrees extreme. It results in a stem parallel to the ground, which is how nearly all quill stems were made. It's also arguably the most aesthetic.
Only if the head angle is 73 deg......
Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓ Broad Selection ✓ Worldwide Delivery ✓
www.starbike.com
Multebear wrote:^But isn't the head angle always between 72 and 74 deg on road bikes?
Just being a pedant..... If you have ahead angle of 72 and use a -17 deg stem you will have a stem angle of 1 deg, thus it will not be parallel with a level top tube.....probably nobody will notice 1 deg....