Head and tail winds

spacemonkeys

If you have a training run, which is head out 10 miles, turn around and come back the same route .... and you do beat your best average speed by a good margin, on a day where you have had a tail wind out and head wind in .. and it was a good wind at that, does it count ? Or should you put the good time down to the wind ?

DaveyL

No, in fact it would be even better without! Because you'll spend less time with the wind behind you than the wind against (if it's an out and back) your average speed will always be worse than for the equivalent effort on a calm day. So well done!

doyler78

Never thought about that one before so I checked it out and DaveyL is quite right. Check it out for yourself - cool tool.

http://bikecalculator.com/veloMetricNum.html

Alex_Simmons/RST

And if doing a time trial in such a scenario, then the modelling indicates that the fastest time is achieved by only a very small moderation of power into/with wind. Very slightly harder into wind, slightly less with it and let the speed be what it may.

Whichever, wind generally* slows you down overall (assuming roughly equivalent distance of head & tail wind).

* there are rare circumstances where it might not be the case, where the wind yaw angles and equipment/rider position combine to actually lower a rider's effective CdA from a normal headwind scenario. I have seen this in action while pursuiting on outdoor tracks.