CdA: the importance of a properly maintained bike

[Velocomp]

To get the most accuracy out of AeroPod, your bike needs to be properly maintained.

I found out the hard way that my bike had a bit of play in the fork tube. How did I find out? When I did sprints, my AeroPod CdA values changed. Not possible...but my ride files showed a 0.1% increase in slope during sprints, even though there was no change in topography!

I eventually found the cause...check out this video.

https://youtu.be/HeDIzME2e84

[mir]

Hi John,

This is easy fixed. untighten the stem bolts and tighten the screw on the top of the fork which then will press the spacers down securing the fork

Tools required: 4 or 5 mm allenkey and a torque wrench.

[Velocomp]

Yup, got it fixed yesterday. Local bike shop did it for free!

It was easy to do, but many things are, after you know what to do!

[ChrisW]

FYI, it's normally called a steering column not a fork tube and we'd normally say that the play was in the headset (i.e., the bearings) and not in the steering column (you'd have a serious problem if that wasn't rigid).

I wanted to reply to your YouTube video, but comments are disabled there.

[SoaringBear]

I agree. It happens. I recently found that my headset was not tightened all the way and had play in it. I took the fork out, cleaned everything out and regreased the bearings. Much better now. The root cause of the looseness was that I hadn't sufficiently tightened screw at the top of the fork as mir said.