Technical R&D: 2020+ BMW S1000 RR (K67) Linear Link Kits by Motorrad One. October 15 2020
Why choose our innovative, patent pending Motorrad-One (“M1”) Linear Rear Links for your 2020+ BMW S1000 RR? Well to help you make an informed decision based on our technology, engineering and the fundamental physics that shaped our mission in designing and manufacturing the world’s first and most advanced K67 linear link for road racing or drag racing, we wanted to show you the behind the scenes R&D that went into them. Whether you’re road racing on the track, or drag racing your BMW S1000 RR – we have a link to fit your goals. Winning races. #racetrackweaponry
Physics & Fundamentals
Motorcycle rear suspensions use the laws of physics to dissipate forces acting on the rear wheel in order to provide a smooth and stable ride. Every system has a unique geometry and components to allow them to function to specific manufacturer’s needs. Rear suspension systems are comprised of various components, including the rear shock and spring, the suspension rear link, locating rod and the swing arm mechanism. There are many forces that a rear motorcycle suspension and its accompanying swingarm have to withstand in order to allow it function effectively.
The main components of the new generation K67 rear suspension system of the 2020+ BMW S1000 RR and the M1000 RR incorporates a long deflection lever and smaller locator rod that connects the motorcycle’s frame to the rear DDC shock/swingarm. Although BMW’s original rear suspension for the 2020 model RR is an idealized version, the power delivery is not linear in the force per distance compressed – it’s overly progressive. Why? Progressive power delivery is often used in the industry to produce specific effects making the suspension soft at the beginning of the swingarm movement but much firmer towards the end of the movement. It’s also called an “Increasing Rate Suspension.”
3D Modeling and Analysis of Designs
Understanding load transfers that occur on motorcycle suspension is important. During acceleration, several forces are present in the rear suspension, namely squat and anti-squat. Squat refers to the tendency for the rear suspension to compress upon acceleration due to rearward rotation from acceleration and aerodynamic forces. This load transfer is caused by four factors. These are: inertia from the force needed to accelerate the bike, aerodynamics and drag forces, hill descent (when applicable), and torque from the crankshaft and clutch. However, these forces are at least partially compensated for in swingarm/linkage and chain movement.
In the BMW design, the primary goal was to provide progressively stiffer resistance to wheel displacement while using a constant rate spring in the original DDC rear shock. In order to achieve this progressive rate at the rear axle, it required certain angles of linkages in the suspension geometry. However, it was noted that the effect of certain changes in linkage angles tended to cancel each other out. This meant a lot of effort and engineering would be put into Motorrad-One’s complex suspension linkage system to deliver truly linear results that keep the bike stable both in the apex and at a launch from a race start.
In order to accomplish that, we had to completely redesign the parts. If you see the above 3D model, we show you the original progressive deflection lever (render in Gold) of BMW Motorrad compared to our Motorrad-One linear deflection lever (render in Silver) showing the substantial redesign.
Final Design Selection
The following chart of the Motorrad-One (“M1”) Linear Rear Links have been designed and engineered with advanced chassis state-of-the-art MotoSPEC software that is used at the highest levels of racing including WSBK and MotoGP for more rear tire traction on the street or race track - especially with higher horsepower engines. The ‘Rear Wheel Rate’ shown below in black is the OEM progressive swingarm movement vs. the improved Motorrad-One (“M1”) Linear Link Kit shown below in red in MotoSPEC chassis software. Our power delivery is consistent whether your bike is on a straight line or leaned over in a curve for more tire grip and less rear suspension movement. Look!
To engineer a better rear linear link (“flatter curve”), we measured and plot these rear suspension and chassis points in the MotoSPEC software to see what BMW did. As you can see that we can compare the OEM vs. our M1 linear design, and when we were pleased with our final engineering – we created a prototypes and put them out in the real world to test and receive feedback by data logging and real world results on the BMW S1000 RR.
We at Motorrad-One (“M1”) are extremely pleased to bring you the best parts for your BMW motorcycle that have all the research, development and engineering used by top racing teams worldwide. If you have any questions about our M1 Linear Rear Suspension Links, or require technical support, please call +1 646-360-0850 or email firstname.lastname@example.org.
Here are some testimonials from world level teams that use the chassis engineering software from MotoSPEC:
"MotoSPEC was an essential tool in winning the British Superbike title. It enables us to visualize all effects of any potential changes and saves many test runs of incorrect setups. Invaluable in building a rider's confidence in his bike and team." Ian Prestwood, Honda Racing
"MotoSPEC chassis software has been used by K-Tech Suspension for several years and is being used in world championships, BSB and AMA Championship by our team. It has proved to be invaluable to our technicians and design team. MotoSPEC is not just another tool in your toolbox but is THE tool to give you the most accurate and best setup options for your motorcycle. We would not be without it." - Ken Summerton, Technical Director, K- Tech Suspension Ltd.
"MotoSPEC has proved to be an essential tool, not just during the race weekend but also testing and design. For the Moto3, Moto2 and the Forward Yamaha motorcycles, MotoSPEC has become as valuable as the stop watch and tire warmers for me and all the teams that we have supplied. MotoSPEC is the only one that gives me accurate information that I can use to understand the motorcycle's performance and set-up options." - Mark Taylor, MotoGP engineer
"MotoSPEC chassis software has been a very valuable tool in developing our racing motorcycles. We have used it exclusively with excellent results. It is very easy to use, intuitive, informative, and extremely helpful for chassis set-up and also for recording and preserving the weekend’s activities." - Pete Mauhar, Michael Jordan Motorsports