How does number plate placement affect aerodynamics in cycling races?

Question

I have observed riders moving their number plates in cycles during the race. Is the position of number plates significant in relation to aerodynamics?

Answer 1

Positioning of the registration plates could prove beneficial in reducing drag. Placing a registration number on the standard position on the bike could drain up to 12.3 watts, or 9 minutes and 19 seconds for a distance of 200 miles. As for considering individual advantage or improvement, placing the number plate on the head tube could decrease this to only 2.9 watts or 2 minutes and 8 seconds. The most promising result was the use of the same number plate that is preferably placed parallel with the wind by burying it in the frame, and that cost only 0.7 watts or 30 seconds. Judging on placement of number plates, it should be done bearing in mind the rules of the race so as not to lose the race because of disqualification.

Comments

Race promoters needs to actually enforce proper plate placement if the numbers are that crazy. Huge disadvantage to those who follow the rules. Amazing as always, DJ

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In terms of number plates, gravel organizers should realize it’s not mtb. They should do road style. A number pinned on the back of the jersey and/or a smaller one on the seatpost

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I did a time trial and they had us pin the numbers on the left rib cage area of our jersey.  Myself being smaller  couldn't help but notice larger riders have it much easier pinning the number, while maintaining a more flush surface.  We should use those programmable LED Lights like you see on bike spokes (or something along those lines).