How long you can go between changes depends a great deal on which oil you use. Looking at these two examples, you should be able to see that. Look at the properties section at the bottom of the page, at the SUS viscosity. Note that in the first UOA, Shell Rotella is below grade for a 40 wt, having been sheared down to a 30 in 930 miles in a road bike. By contrast, in the second, Amsoil MCV is still well above minimum for a 50 wt, even at twice the mileage.
...also the oil changes. every 4-5 good rides is ok. changing the oil after every race or every trail ride is silly. ....i change the oil and filter every 4-5 all day trips ...
You may be right, you may be far from it. Depends on the oil.