Level Speed, Uphill Speed, Downhill Speed
By Paul Lew - Director of Technology and Innovation, Reynolds Cycling
Will a heavier frame or fly-wheel effect from a heavier wheel benefit a cyclist by adding speed to
his descent to make-up time from a climb?
The assumptions are as follows:
The cyclist’s power output is constant for all inclines, declines, and flats. All components are all identical.
Level speed = 20 mph, uphill speed = 13.2 mph, downhill speed = 27.8 mph
Using this chart and formula it will take a cyclist 45.45 minutes to climb 10 miles uphill. It will take a cyclist 21.58 minutes to go 10 miles downhill. The total combined time up hill, and down hill = 67.08. The same cyclist could cover 20 miles on level ground in 60 minutes. To summarize a +/- 2.5% incline & descent will increase the total time to cover 20 miles by 7.08 minutes, dropping the average speed to 17.89 mph. The additional 7.08 minutes is equal to an additional 2.36 miles (on level road). In order to make up the time lost going uphill, the cyclist would have to descend at an average speed of 40 mph to maintain an average speed of 20 mph over the 20 mile course.
As percent grade increases, using the chart in Illustration A the following charts can be used to gauge the effect of an incline as compared to level ground. The time and distance values represent additional time (and corresponding distance equivalency) for a given incline as compared to level road. All times are based upon a 20 mile course with one uphill climb beginning at mile 0,
and peaking at the 10 mile mark, and one descent, ending at the 20 mile mark.
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