Handlebar Stem Geometry- Mtbr.com

# Thread: Handlebar Stem Geometry

1. ## Handlebar Stem Geometry

Newb questions:

I am looking for a new stem to replace the stock stem on my 09 Rockhopper. I would like the bars higher.

The stock stem has 7 degree rise and a 31.8mm clamp. Where is this 7 degrees measured? If I were to guess, I would say the angle is based on a perpendicular to the axis of the head/fork tube clamp I ASSUME a higher rise stem would have a larger angle but I wanted to be sure before I ordered another stem.

Also, where is the stem "length" measured? Center of bar clamp to center of fork clamp along axis of stem?

Does anyone have a picture illustrating these dimensions?

Thanks!

2. Originally Posted by BigMark
Newb questions:

I am looking for a new stem to replace the stock stem on my 09 Rockhopper. I would like the bars higher.

The stock stem has 7 degree rise and a 31.8mm clamp. Where is this 7 degrees measured? If I were to guess, I would say the angle is based on a perpendicular to the axis of the head/fork tube clamp I ASSUME a higher rise stem would have a larger angle but I wanted to be sure before I ordered another stem.
Yes, you are correct
Also, where is the stem "length" measured? Center of bar clamp to center of fork clamp along axis of stem?
Yes, usually.

Here is a good chart to give you an idea of how a new stem will effect the reach and height of the bars. Keep in mind that the angles given in the chart are measured from the ground, so you need to factor your bikes head angle into it. If you don't know it, 70 degrees is a good approximation, so a 0 degree rise stem would be 20 degrees on that chart.

3. Outstanding! A picture is worth a thousand words.

4. i get some higher rise bars rather than a more angled stem. you can get some stronger/ stiffer/ lighter bars that will enhance your bike more than a new stem.

5. Originally Posted by b-kul
i get some higher rise bars rather than a more angled stem. you can get some stronger/ stiffer/ lighter bars that will enhance your bike more than a new stem.
The more rise a bar has the weaker it is at the same weight (bending the tube weakens it unless you add material). Stem is an easy way to go, and usually cheaper, if you like your bars.

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