Ningishzidda
Senior Member
A friend and I are planning our first century ride. What is a realistic average speed.
We usually do 20-30 miles at 15-16mph
On another web forum, I suggest there is a simple formula for speed targets for longer rides based on known speeds for shorter rides.
Assuming you are comfortable riding 25 miles at 15 mph, the target speed for a longer ride is calculated from the % increase of ride length and the Natural Log of that percentage.
In your case, it is a 400% increase from 25 to 100 miles. Ln for 400 is 6. Your target speed will be 6% lower than 15 mph, which is 14.1 mph.
This bit of maths is deduced from David Wilson and Frank Whitt’s studies of touring cyclists. The cyclists’ riding duration and resultant average power output showed a logarithmic relationship.