With more data, we see the correlation coefficient for the Pearson's test decrease (.69) and the p value increase past my CI threshold of .05 (2.53). Still, the Spearman's test produces a perfect correlation coefficient of 1 with a p value of 0. The results of the tests for the larger data sets do not necessarily undermine the results of the previous tests with the data for male riders born between 1965 and 1996. But they do suggest that the correlational relationship between birth year and average ride duration isn't quite so cut and dry. An additional analysis could further explore the limitations of Pearson's and Spearman's tests in this context.
For anyone who is interested, you can find my data wrangling and analysis on GitHub using the following link: 
https://github.com/seeess1/PUI2018_shb395/blob/master/HW8_shb395/assignment2.ipynb