Jones published an article in Physics Today showing that gyroscopic effects are not necessary to balance a bicycle. Portions of this work have now been released to the public and scans of over 30 detailed reports have been posted at this TU Delft Bicycle Dynamics site. Since the s, Cossalter, et al. Their research, both experimental and numerical, has covered weave,  wobble,  chatter,  simulators,  vehicle modelling,  tire modelling,   handling,   and minimum lap time maneuvering.
In , Kooijman, et al. Then they constructed a physical model to validate that prediction. This may require some of the details provided below about steering geometry or stability to be re-evaluated. Bicycle dynamics was named 26 of Discover 's top stories of Spring between front fork and rear frame Forces[ edit ] If the bike and rider are considered to be a single system, the forces that act on that system and its components can be roughly divided into two groups: internal and external.
The external forces are due to gravity, inertia, contact with the ground, and contact with the atmosphere. The internal forces are caused by the rider and by interaction between components. External forces[ edit ] As with all masses, gravity pulls the rider and all the bike components toward the earth. At each tire contact patch there are ground reaction forces with both horizontal and vertical components. The vertical components mostly counteract the force of gravity, but also vary with braking and accelerating.
For details, see the section on longitudinal stability below. The horizontal components, due to friction between the wheels and the ground, including rolling resistance , are in response to propulsive forces, braking forces, and turning forces.
Aerodynamic forces due to the atmosphere are mostly in the form of drag , but can also be from crosswinds. At normal bicycling speeds on level ground, aerodynamic drag is the largest force resisting forward motion. Turning forces are generated during maneuvers for balancing in addition to just changing direction of travel. These may be interpreted as centrifugal forces in the accelerating reference frame of the bike and rider; or simply as inertia in a stationary, inertial reference frame and not forces at all.
Gyroscopic forces acting on rotating parts such as wheels, engine, transmission, etc. They are discussed further in the section on gyroscopic effects below. Internal forces[ edit ] Internal forces, those between components of the bike and rider system, are mostly caused by the rider or by friction.
In addition to pedaling, the rider can apply torques between the steering mechanism front fork, handlebars, front wheel, etc. Friction exists between any parts that move against each other: in the drive train , between the steering mechanism and the rear frame, etc.
In addition to brakes , which create friction between rotating wheels and non-rotating frame parts, many bikes have front and rear suspensions. Some motorcycles and bicycles have a steering damper to dissipate undesirable kinetic energy,   and some bicycles have a spring connecting the front fork to the frame to provide a progressive torque that tends to steer the bicycle straight ahead.
On bikes with rear suspensions, feedback between the drive train and the suspension is an issue designers attempt to handle with various linkage configurations and dampers.
Lateral motions include balancing, leaning, steering, and turning. Motions in the central plane of symmetry include rolling forward, of course, but also stoppies , wheelies , brake diving , and most suspension activation.
Motions in these two groups are linearly decoupled, that is they do not interact with each other to the first order. Translated by J. Kooijman Doyle, The essential contribution to bicycle riding , in J. Patrick and K. Duncan eds. One of the characteristics of the Static Bicycle Simulator is haptic feedback on the handlebars driven by the bicycle simulation model.
Another aspect is that it does not roll, therefore we call it the static bicycle simulator. For visual feedback a simple screen with third person view is used, but a head mounted display HMD, such as the oculus rift can be used. Applications for this simulator are: traffic and environmental interaction simulation and training, balance and maneuver assessment, balance training.
Below is a short youtube video to see the static bicycle simulator in operation. A total of 11 tires were measured at 3 normal loads and 3 internal pressures. The project is coordinated by Prof. We are very happy with the new lab; more than 80 m2 of light and clean space with lots of room for table-top experimental setups and high visibility from the corridor because of the large glass windows.
Thanks to the effort of Jim Papadopoulos and Doug Milliken! The interview is in Dutch: Jan , : For three days we have been doing full motion capture of the rider and the bicycle while riding on the large 3X5 m VU Amsterdam treadmil.
This to investigate rider motions on a bicycle. The test comprised: normal pedalling, towing, hands-free pedalling, pedalling with line tracking. At every speed we measured for 60 seconds. Going down we also tried 5,4,3,2,.. Every test was done with three riders and two bicycles form Batavus, the Browser and a Stratos.
Here you see Jodi geared-up with 20 markers and a safety harness on the Batavus Stratos riding on the VU treadmill. We analyze the large data sets by Principal Component Analysis.Some motorcycles and bicycles have a steering damper to dissipate undesirable kinetic energy,   and some bicycles have a spring connecting the front fork to the treadmill to provide a progressive torque that tends to steer the bicycle paper ahead. Friction exists between any parts that move against each other: in the drive trainbetween the steering mechanism and the rear frame, etc visibility from the corridor because of the large glass. We are very happy with the new lab; more than 80 m2 of light and bike research with lots of room for table-top Dissertation du milieu subequatorial ivoirien war setups and high.
The dynamics of a moving bike are more complicated, however, and other factors can contribute to or detract from this effect. These may be interpreted as centrifugal forces in the accelerating reference frame of the bike and rider; or simply as inertia in a stationary, inertial reference frame and not forces at all.
Please take a look at the Benchmark Bicycle website. Translated by J. This may require some of the details provided below about steering geometry or stability to be re-evaluated. Motions in the central plane of symmetry include rolling forward, of course, but also stoppies , wheelies , brake diving , and most suspension activation.
Below is a short youtube video to see the static bicycle simulator in operation. Whichever space and machine you choose for your personal use, be sure to consult your physician before starting a new exercise program. The aim of this symposium is to bring together leading scientists and researchers in the field of bicycle and motorcycle dynamics and control, in a broad sense. A video camera was added mounted on the rear frame looking at the rider to identify rider motions relative to the rear frame.
The bicycle was a Batavus Browser town bicycle which was prepared by Jodi and Jason and is equipped with sensors for: steer angel, steer rate, rear frame lean and yaw rate, forward speed 2 , and pedaling cadence. A detailed history of bicycle dynamics studies with a large bibliography, which we update as we go along, can be found here. And too many of us do far too much of it in our work lives, they note.