Friday, July 15, 2011

Headset Adjustment

After riding the Hospitality Highway Century on Sunday, July 10th I felt that I just wasn't getting aero enough on my bike.  So, I decided to make a small adjustment to my bike headset.  My headset has a total of about 1 15/16" of spacers including those above and below the stem.  Before I did anything I marked the headset screw with a black marker.  Then I removed the screw.  The mark should tell me about where to stop when I re-tighten the screw.  I used a torque wrench to remove the screw but it was so loose that it didn't indicate any torque at all.
Headset screw with mark indicating starting position
There are 3 spacers above the stem and 3 spacers below.  The spacers vary from largest to smallest at approximately 3/8" to 5/16" to 1/16" in width.  The spacer dimensions are probably in metric.
Handlebar stem position before lowing
The 3 spacers above the stem totaled about about 7/8".  The 3 spacers below the stem total about 1 1/16".  That's a total of about 1 15'16" of spacers.  The 5/16" spacer below the stem and above the 2 - 3/8" spacers is barely visible behind the cable. 
Handlebar stem position after lowering
I moved a large and medium sized spacer from below the stem and placed them above the stem.  So, I lowered my stem and base bar a meager 11/16".  After retightening everything I took a short ride around my subdivision.  The difference in my riding position seemed significant.  I could feel the difference in my lower back and on my saddle.  My next ride will really tell the tale.  I'm optimistic that my body will adapt to the change and that I'll see some improved aerodynamics.

Thanks for reading!