Major bike geek moment

I had co-riders today. Santini is in town to attend a family funeral. She needed a few miles to defeat the ravages of travel. TOPWLH was also convinced to make her season debut. TOPWLH gave lie to the old adage about you never forget how to ride a bicycle by completely forgetting how to shift. Shifting, however, is easily and quickly re-taught and we were soon on the road.

Roseville was spectacularly pretty today. We stopped at the top of a hill for this photo. The guy who lives in the house was putting stuff in his car and Bianchi Babe inquired if it was alright to enter his yard for the photo. She then set out to make friends with him. She does this because she is incorrigibly gregarious. She discovered that they intended for this to happen, having themselves planted the four flowering crabapple trees which were today in spectacular bloom.Babes for scale.

The only problem with the ride was that Santini discovered that the bicycle computer on the Bianchi Eros was underreporting miles traveled. This is a problem that has to be solved.

Upon arriving home I got out the manual and prepared to recalibrate. The manual has standard size information but did not have the exact calibration number for the tire size on the Eros, a 700x25. I had replaced the battery on that computer since the last time serious miles were ridden on that bike and I remembered that I had made an extrapolation from the numbers that were available, 2124 for 700x26, and 2170 for 700x38. The extrapolation seemed correct but it was producing a serious mileage and speed computation error.

This called for a roll out. Roll out is how really, really serious bike geeks determine the calibration number for their bike computers. You mark a spot, roll the bike tire one circumference, measure the distance in millimeters and that is your calibration number. Obviously you have to be a serious geek to engage in this sort of activity.

But with the able assistance of the other serious bike geek in attendance I went out in the driveway and did a roll out. I only had an inch tape measure but I knew the conversion for inches to millimeters. The roll out distance was 83 5/8 inches, almost 8 feet. Who knew, 8 feet! When converted to millimeters this comes to 2124, the number given in the computer manual for 700x26 tires.

Whoa, major bike geek moment. We successfully determined that the tires labeled as 700x25 are in fact 700x26. With this information now in hand the bike computer was successfully recalibrated.

I pronounce myself to be an extremely self-satisfied bike geek. And, it was a totally bloggable moment.