Motorcycles see varying extreme conditions whether it’s motoGP or the dakar rally, specifically the problem DDC brakes is attacking is the dirt bike brake rotor industry. Brakes on motorcycles are often made of generic steel which yields good strength. However, in most designs during extreme testing such as extreme heat and weather conditions, most designs fall short in construction, materials, manufacturing process or longevity. Dirt bikes see the most extreme conditions across the world, for example the motocross track, supercross, desert racing, or long distance racing. Brakes are an important part of offroad racing and it would not exist without high quality braking components.
Most high-performance cars can be seen with carbon ceramic rotors or two piece rotors which reduces rotational mass and has better heat dissipation. Applying this concept to motorcycles can address the problem the industry currently has while improving braking systems on motorcycles. Therefore, by taking normal rotor dimensions and redesigning them with a better material as well as basic design, DDC brakes can achieve brake rotors that have better heat dissipation, better product life, extensive warranty and attractive design.
Proof of Concept
The PoC was designed to answer design questions that could not be answered with the classical or solid works analysis. The focus is to test the design while also trying to disprove the calculations or to break the disc rotor. The rotor will be laser cut out of AR400 steel, and tested in real time on the team’s motorcycle. Two tests consisting of heat and brake endurance will demonstrate the feasibility of rotor in real world applications. The questions that will be answered using the proof of concept are, does the rotor satisfy the set objectives? What issues need to addressed after testing? Are there issues that were no expect from just analysis alone?
The big manufacturers of motorcycles such as Yamaha, KTM, Suzuki, Kawasaki, and Honda package together dirt bikes to be ridden off the dealership floor straight to the dirt. This often means that to stay competitive with each other, the material and manufacturing costs on certain components are sub-par for a racing atmosphere. D.D.C. brake rotors are stronger using AR400 steel and offer significantly better cooling. The purpose of the project is to provide brake rotors that will not fail under extreme off road conditions for customers that demand peak performance out of their brakes rotors. The original equipment manufacturer provides stainless steel brake rotors that are prone to cracking through stress fractures caused by heat cycling. AR400 steel does not share the same properties as the generic stainless steel rotors currently available to consumers.
The final design after testing was determined using Solid works FEA analysis, existing brake system information, and proof of concept testing. The overall design did not change significantly in direct relation to proof of concept testing. However, the team felt that minor changes were necessary in order to strengthen the rotor, and provide a better brake pad cleaning surface. After comparing the team’s brake rotor to competitors and examining malfunctions in the competitors brake rotors, the team was able to identify potential weak point in the initial design. Increased the braking surface, added more cooling slots, and increased the amount of material on each side of the cooling slots to potential weak points that could result in cracking.
Team 14 used a variety of machines for the production of the initial prototype and the full production models.
1. Initial the brake rotor is designed in solidworks based on dimension for each major manufacturer, as each rotors bolt pattern and number of bolts changes from bike to bike.
2. Once the rotor is designed, the .dxf file is sent down to DD wire which is a laser cutting facility down in Temple City, California . The company also holds D.D.C.’s AR400 steel plates that are ordered from
3. Once the rotors are cut, their thickness is too large at ¼”. The rotors are then shipped up to D.D.C.’s headquarters in Minden, Nevada. 4. Each rotor then needs to be at a final thickness, depending on each bike and whether it is a front or rear rotor determines the final thickness. 0.17” for the front rotor and 0.12” for the rear rotor.
5. The rotors are ground to this final thickness using a blanchard grinder at G&S grinding Co. The team was unable to obtain of a photo of the actual blanchard grinder, however looked exactly like the figure below. After grinding a set of rotors, they are checked with three thousandths of inch for flatness.
6. The rotors are then in the finals stages of being processed, AR400 steel needs to have a protective coating to avoid corrosion. Zinc was chosen for its finish and ability to protect the steel from rust and pitting. First the rotors are put into a ceramic stone tumbler, and finally zinc plated. 7. The final product is shown below, after this the rotors will be packaged and be ready for retail sales.
8. The rotor is purchased and ready to mount to the motorcycle. Full assembly is show below is a rear rotor mounted on a Yamaha motorcycle. Mounting the rotor is simply taking off the rear wheel, removing the old rotor, installing the new rotor with new rotor bolts as they are torque to yield, use blue loctite to insure bolted. Consider torque values specified in the motorcycles manual.
Testing and Results
Two tests were used to determine the viability of the design and material choice, currently the rotors are still under testing through weekend riding with members of the team and the owners of Delaney drive components. With the testing that is currently done the rotors have performed very well, each user reports a linear lever pull, no brake fading, no cracking, and major issues with braking force. While the company is going to do further testing, within the scope of the last two semesters the project was a complete success with no major issues.
D.D.C.’s rotors solve the issue of rotors that are not strong enough for serious off road racing, in addition the rotors offer customers a better product for everyday riding.
Test 1: Heat warping and quenching
The goal of this test is to determine if any warping can happen to the AR400 steel in extreme heat and during sudden cooling. This test is basic in that it is heating the rotor up to 600-700 degrees Fahrenheit in specific locations to exaggerate heat distribution and cause possible warping. Using two blow torches the rotor is to be heated up to be as hot as possible then cooled as quickly as possible. This will be repeated twice, once with just the rotor and once with the rotor mounted onto the rear wheel. This will determine if there is a heat sink effect that the team believes will happen when the rotor is mounted to the cast aluminum hub.
Test 2: Heat distribution and dissipation mounting to the motorcycle
The goal of this test will be to determine the maximum and failure temperature of the DDC brake rotor. This test will include measuring the temperature of the brake rotor when direct heat is applied to it in order to determine/prove the deformation temperature of the rotor material. This will allow the team to determine a threshold for the failure temperature of the brake rotor. If the temperature of deformation matches the temperature that research has shown, the team will know that the calculations were done correctly and will be able to move on the next step of the experiment. With two portions of the test of the bike being on the stand and being ridden by a professional rider, the rotor will be tested with the weight of the wheel and the weight of the motorcycle/ combined.
Results from Tests #1 and #2:
During the direct heating portion of the test the rotor would not get hotter than 235 degrees Fahrenheit while in the vice grips, team DDC then quenched the rotor and had no warping or failure. The next step was to mount it to a spare hub and determine how much heat flowed into the brake hub by conduction. Team ddc was unable to peak the temp higher than 785 degrees Fahrenheit in one localized spot on the rotor while maintaining 235-degree average over the entire rotor. Therefore we quenched, validated that there was no warping and proceeded to test step two.
During the stand testing, the heat spike was not as appreciable as DDC had expected, with an average heat gain of 150 degrees Fahrenheit. Using five different wheel speeds did not drastically change the temperature of the rotor, instead of using all five gears for different wheel speeds only first gear was used to keep the torque of the engine at its peak. We then sustained braking over a period of 30 seconds and the rotor heated up to 150 degrees Fahrenheit, not wanting to overheat the engine on the bike, team DDC applied direct heat in conjunction with a minute-long period of sustained braking, the rotor only heated to 300 degrees Fahrenheit and took 10 minutes to cool to room temperature under free convection. The team believes that under forced convection due to riding the rotor will not exceed a temperature of 400 degrees, and determining that it is a safe product to sell.
Meet the Team
Mechanical engineering student with a renewable energy minor graduating in May 2017. Lifetime Nevada resident with experience in Motorsports manufacturing and MEP design. Passionate about learning and giving back to the community through volunteering. Justin is working towards getting into the renewable energy sector, in solar and geothermal power plant design.
Mechanical Engineering student graduating in May 2017. Northern Nevada local with experience in the powersports industry, passionate about going fast. After graduating the Sloan plans to get into the motorcycle industry.
Anthony is a mechanical engineering senior at the University of Nevada; born in Silicon Valley. He is passionate about his undergraduate academic pursuits and the relationship between academics and industry. He has had one engineering internship, and is looking to further his industry experience before graduation. He is also considering the possibility of graduate research at UNR, and would like to proceed in the direction of military defense or energy.
Joshua is a senior Mechanical Engineering student currently attending the University of Nevada, Reno. He is planning to graduate in May of 2017. Born and raised in Reno, Joshua has a strong connection to Nevada. He also has a passion for working with cars and trucks. However, after graduation Joshua plans to get certificates in construction management after graduation from UNR. He wants to pursue a career in construction management.
Reece is a mechanical engineering senior at university of Nevada Reno and is planning on graduating in May of 2017. He will also be receiving a minor in business administration. Reece was born and raised in Sparks Nevada and enjoys the outdoors. He is currently employed at MSA engineering designing and drafting mechanical systems and plans on continuing with this company after graduation.