Mudguards are MORE aero: study shows that optimum drag reduction is achieved with mudguards on

Ever been reluctant to stick your mudguards on for the winter through fear of losing out on sweet aero gainz? Well according to a new study you can fear no more and keep them on year round, because the results shown that drag can actually decrease with mudguards on your bike. 

16 of the best mudguards for any type of bike

It's long being thought that mudguards affect the aerodynamics of a bicycle in some way or another; and if you think about it, more coverage and a smooth surface over your tyre could in theory make for better aerodynamics. The study in the SAE Mobilus engineering journal - titled 'Effect of Fender Coverage Angle on the Aerodynamic Drag of a Bicycle' - explored the effects of various types of mudguards that provided wheel coverage from 60° through to 270°. Using a validated computational fluid dynamics (CFD) model in SolidWorks Flow Simulation, the model predicted that aerodynamic drag coefficient reduced with mudguard coverage angles of up to 135°, and started to increase thereafter.

An analysis of the effect was carried out at velocities of 6 metres per second (m/s), 8 m/s and 10 m/s, and the results were found to be similar to the CFD predictions, with the minimum aerodynamic drag coefficient at 135° occurring in all the cases. The researchers eventually concluded that there was indeed an observed optimum decrease in drag coefficient - the bike with mudguards had 4.6%, 4.5% and 4.6% less drag than the bike without mudguards at 6 m/s, 8 m/s and 10 m/s respectively.

We're not too sure what type of bike and what type of mudguards were being used in the study, but are currently doing some digging to get further info about the methods used. In the meantime, there are some mudguards already out there specifically designed to be more aero than without, such as the Null Winds Aerofender shown above - they even claim the fairing outperforms any aero wheelset in strong headwinds, and will net you an advantage of between 10-20% in headwinds compared to bare wheels.