Yet Another Cycling Forum

General Category => The Knowledge => Further and Faster => Topic started by: quixoticgeek on June 09, 2018, 01:04:31 am

Title: Wind impact
Post by: quixoticgeek on June 09, 2018, 01:04:31 am

Yesterday I was out for a leisurely ride in Flanders. Most of the route was totally flat. I'm used to cycling in such terrain in Noord Holland, and typically on a ride of more than about 25k, will average  20kph. Today I did 77km at an average speed of 24.7kph. Nearly 25% faster than my usual speed. There was a tail wind, but it was ever so slight. Yr.no says 1-2m/s. So under 7kph. I've had tailwind before (rare, but it does occasionally happen), but even in a stiff breeze strong enough to move branches on trees (which today's didn't), I've not been able to manage such a speed for so long.

This is a long way of getting to the question, how much impact can be reasonably expected from a tailwind? If I typically do 20kph, how strong would the tailwind need to be to increase my speed to 25kph, without requiring more power ?

J
Title: Re: Wind impact
Post by: Samuel D on June 09, 2018, 09:44:42 am
There was a tail wind, but it was ever so slight. Yr.no says 1-2m/s. So under 7kph. […] If I typically do 20kph, how strong would the tailwind need to be to increase my speed to 25kph, without requiring more power ?

About the wind speed you had. However, the wind speed at aggregate bicycle-height would be less than the wind speed as reported by weather services, so perhaps you did have a good day.

That said, if you had had a 7 km/h headwind, I doubt you would have described it as “ever so slight”. Wind has a large effect on cycling as expertly described by Osman Isvan here. (https://docs.google.com/file/d/0B-pZ1ubTOGTtNjJjMTM3NWItZDRkMi00YmJiLWEzM2EtNTUzZDM4YzY3YmRl) (I just about remember when magazines still published this sort of content. Sigh.)