I have been analysing the data from our last tandem century. On one of the climbs we did approximately 1600 ft in 8 miles. The climb went serious for the last 5 miles where I recorded grades running from 10 to 27%. There was one very brief section of 31%. We found ourselves thinking the 5-7% sections were nice breaks. We were slogging it out in grandma for most of the climb and were passing many singles as we were able to maintain a very steady, relentlous rate of climb. My recorded speed at 27% grade was 5mph. I did not record anything lower than that.

The answer is yes the hills slow you down but if you use the downhills and flats efficiently you can maintain a very decent overall average. We are learning more about our climbing abilities with each new challenge.