Originally Posted by
njkayaker
The top edge of the bubble is at the 17' mark.
Isn't the correct reading at the middle of the bubble?
Nope. If you look close at the inclinometer, there are two zero lines, about one bubble length apart. The upper set of numbers is for uphill on the upper edge of the bubble, the lower set of numbers is for downhill and the lower edge of the bubble lines up with those numbers.
Thus, under ideal conditions the top of the bubble is for uphill and lower edge for downhill.
And the bubble changes size with temperature and pressure changes so I only adjust it to the up hill measurements. I never care about how steep a down hill is so I always adjust it to the up hill edge of the bubble. I occasionally have to adjust it because of the bubble shrinking and expanding.
The photo below, I am on very flat ground, the middle of the bubble has no numbers on the scale, only at the top and bottom of the bubble.
ADDENDUM:
I was unaware that Amazon started selling them again. I have looked several times over the past half decade and they were no longer available here. You could only buy them from German sellers. But they have returned.
https://www.amazon.com/Sky-Mounti-Bi...dp/B01L5GL3A8/
If anyone gets one, they are only accurate if you are not changing speed. If you are accelerating or decelerating the measurement is off. I only use the measurement if I am stopped. That is one reason I never measure a downhill, I would rather ride downhill than stop for a measurement.