Downforce and aerodynamics in motorcycle racing

1. Motorcycle Road Racing Winglet Project
Presented by Group 3
Group Members: Chad O’Hara, Matthew Phan, Mario Gutierrez, Mohamed Ahmed
ME 159 (03) - Mechanical Engineering Laboratory
A winglet fabrication project to optimize between downforce and drag to maximize performance.

2. Abstract
● Downforce is directly influence with increased speed based on the implementation of the
motorcycle winglet, thus creating more stability in multiple situations.
● Employ the designed prototype onto the wind tunnel.
● Winglet design is beneficial to use on racing motorcycles with high power to weight ratios
(Minimum 0.8hp/kg)
● Lower power to weight ratios motorcycles will have diminishing return on downforce because of
the increase in drag.
● Winglet is not legalized for commercial use because of the high velocity involvement on public
roads.

3. Background
What is downforce (negative lift)?
● The downward reaction force from the high pressure above and
low pressure below an air shaping element in tandem with the
addition of an upward component to the momentum of the air.
● Downforce from winglets comes at the cost of drag.
Why do motorcycles need downforce?
● High power-to-weight motorcycles are limited in acceleration
due to front wheel lift.
● During deceleration, front tire grip is limited by the normal force
on the tire contact surface, which must be maximize.
History and regulations
● First introduced in MotoGP in 2010 by Ducati (bottom right)
● Regulations on safety and design limitations set by the
Fédération Internationale de Motocyclisme (FIM)
2010:
2021:

4. Objective
● Achieve a downforce of at least 15 lbf.
● Design and simulate multiple design configurations using the SolidWorks-based computational
fluid dynamics software.
● Manufacture alpha prototype.
● Perform wind tunnel testing for comparison with simulated results.

5. Procedure
● Research and Prior Arts
○ All manufacturers in MotoGP (prototype racing machines) have their own winglet
design
○ Many manufacturers of production racing motorcycles are beginning to show up on
the market
○ Investigate research articles on motorsports aerodynamics and airfoil shapes
● Brainstorming and concept selection
○ Number of winglet elements
○ Shape of winglet element
● Solidworks modeling and simulation
○ Initial modeling
○ Flow Simulation
● Fabrication
○ 3D Print
● Wind Tunnel

6. Results
● Selig S1223 Airfoil
○ 86 mph
■ Drag Force: 1.53 N (0.34 lbf)
○ 100mph
■ Drag Force: 9.57 N (2.15 lbf)
■ Downforce: 31.52 N (7.1 lbf)
● Wind Tunnel
○ 86 mph
■ Drag Force: 2.37 N (0.533 lbf)
■ Percent Error: 54.96%

7. Conclusion
● The total downforce from a set of two of our winglets produce
14.2 lbf which is close to our initial goal of at least 15 lbf
● The design is in the alpha prototype phase
○ Mounting points would need to be designed for a specific motorcycle
body
○ Overall shape could be more complex
● Some of the sources of error in the wind tunnel could be
addressed in future experiments
● Marketable product is at least 2-3 iterations from current design

8. THE END
Q&A Session
Thank you!