Rough Draft

So I’ve finished my rough draft of wheel selector, it’s live here:

Mainly the biggest hurdle I’m having is coding the damn thing into a website.

So right now what it is essentially a power estimator given there’s zero cross wind, no rolling resistance, and you’re riding by yourself (aka Ironman). It’s estimating pretty high on the power/work numbers based on my own rides.

What it needs to be a viable wheel selector:

  • Wind included (with inclusion of atmospheric boundary layer effects)
  • Wheel drag across range of wind angles (currently only running for 0 degrees, which means all wheels are pretty much the same)
  • Add rolling resistance
  • Time spent Drafting?
  • TT position
  • Refined bicycle rider CdA (this is pretty rough currently, the topic of it’s own blog post)
  • Add more explanation to what the hell is going on

Other things I plan on doing

  • Some sort of submit to database, involving entering your ride metrics (from power meter). This could help refine CdA measurments, which are particularly difficult to estimate
  • Better interface (ajax implementation, oh the confusing computer languages, why cant everything be like matlab…easy)
  • Step 2:  ?????????
  • Step 3: Profit!

Ultimately I’d like to incorporate something like this into what this guy did here.

But that’s a LONG way off for a side project.

I don’t want a silly plain power estimator, that doesn’t really give you much (plus that’s kinda the reverse solving process from what you need to benefit you as a racing cyclist). With this tool, you could essentially calculate your power needed for say a mountain cilmb, pick which wheelset is best, etc.



  1. Interesting. The CdA came out exactly what I saw on my ride yesterday! I have no idea how it works but i would say you are on the right path.

  2. For the CdA measurement, yes it was.
    Lots of winter clothing made it much higher than in the summer.
    I had it working with a PT. I know a lot of “experts” don’t like it but it provides interesting info.
    End result was the PT and the iBike were different by 1 1/2 watts.

Leave a Reply

Your email address will not be published.