2 MPH is a big difference
This morning I was riding a group event in the flat area East of the city. The winds were fairly stong with much of the ride in a crosswind situation. Anyway, the group was over 20 riders so we were in a double pace line. I had taken my time pulling, went to the back and had rotated to within about 4 slots from pulling again. We were 15 miles into the ride and holding a speed of 22 to 22 1/2 MPH when a couple of guys took the lead and jumped the speed to 24 1/2 MPH.
I immediately went from riding comfortably to suffering. Just 2 MPH made that much difference. After about a mile or so I was not dropped. I was flung off the back. I just could not hold the pace. Fortunately about 6 others had the safe fate at that speed difference, so we started our own paceline.
Actually, I was feeling very good on today's ride, so I found it amazing that my body found THAT much difference. However, I guess the old saying about "the straw that broke the camel's back" is true. There is that one point where everything changes. I know the gage is not the speed, because if you are pedaling directly into a strong headwind the amount of effort to hold 15 MPH could be more that the effort to hold a much higher speed with no wind. What was so interesting this morning was how close the difference between comfortable and suffering.