Height Difference between 6 degree & 17 degree stem

[jimp1234]

I'm in the process of adjusting my fit yet again, and I wanted to get my bars a bit higher. Anyone know offhand how much higher my bars would be with a 17 degree stem versus my current 6 degree?

TIA

-Jim

[C5 Snowboarder]

depends on the length of the arm -- with that you can figure it at .017" per inch per degree of change.

[old_school]

A couple of stem tools for you:

zinn cycles (http://www.zinncycles.com/stemFit.aspx)

habanero cycles (http://www.habcycles.com/fitting.html)

[jimp1234]

Thank guys.

-Jim

[eddief]

http://www.hammerheadbikes.com/docs/stemcalculator.xls

don't be afraid to open it. a legit excel spreadsheet for this exact purpose.

[Baum]

Hello Jim,

Assuming your 6 degree stem is 120mm and has a collar height of 42mm (Ritchey/Deda) switching to a 17degree with the 120mm length and 42mm collar will give you an extra 37mm.

Cheers!

[Dave]

Hello Jim,

Assuming your 6 degree stem is 120mm and has a collar height of 42mm (Ritchey/Deda) switching to a 17degree with the 120mm length and 42mm collar will give you an extra 37mm.

Cheers!

Don't think you're correct.

The rise of a stem is simply the sine of the angle relative to the ground times the stem length. With a +6 (96) degree stem and a nominal 73 degree HTA, you have an angle of 23 degrees relative to the ground. The rise would be 120 x sin23 = 46.9mm. With a +17 (107) degree you'd have an angle of 34 degrees relative to the ground. The rise would be 120 x sin34 = 67mm. The difference is 20.2mm.

Also of importance is the horizontal length of the stem, which is the cosine of the same angle times the stem length. A 120 x 96 degree stem has a horizontal length of 120 x cos23 = 110.5mm, while a 107 degree stem has a length of 120 x cos34 = 99.5. If you want to raise the bars and not also bring them closer, you need to buy one size longer stem in the 17 degree angle.

If you make these same calculations for a given stem in the upward versus the downward angle (96/84 or 107/73), you will find the results are not 100% accurate, because the center of the stem extension does not intersect the center of the steering tube clamp (collar).