Editing Tire (section)

=== Dynamics ===

* ''Balance'': Wheel-tire combinations require an even distribution of mass around their circumferences to maintain [[tire balance]], while turning at speed. Tires are checked at the point of manufacture for excessive static imbalance and dynamic imbalance using automatic tire balance machines. Tires are checked again in the auto assembly plant or tire retail shop after mounting the tire to the wheel. Assemblies that exhibit excessive imbalance are corrected by applying balance weights to the wheels to counteract the tire/wheel imbalance. An alternative method to tire balancing is the use of internal tire balancing agents. These agents take advantage of centrifugal force and inertia to counteract the tire imbalance.<ref>{{Cite book |last=Sabry |first=Fouad |url= https://books.google.com/books?id=KXOXEAAAQBAJ&dq=Internal+Tire+Balancing+Agents&pg=PT78 |title=Airless Tire: Reinventing the Wheel |date=2022-10-25 |publisher=One Billion Knowledgeable |language=en}}</ref> To facilitate proper balancing, most high-performance tire manufacturers place red and yellow marks on the sidewalls to enable the best possible match-mounting of the tire/wheel assembly. There are two methods of match-mounting high-performance tire-to-wheel assemblies using these red (uniformity) or yellow (weight) marks.<ref>{{cite web|url= http://www.yokohamatire.com/utmatch.asp |title=Tire Match Mounting and Balancing - Yokohama Tire |website=yokohamatire.com |access-date=2007-07-24|archive-url= https://web.archive.org/web/20070929183155/http://www.yokohamatire.com/utmatch.asp |archive-date=2007-09-29 |url-status=dead}}</ref>
* ''Centrifugal growth'': A tire rotating at higher speeds tends to develop a larger diameter, due to [[centrifugal force]]s that force the tread rubber away from the axis of rotation. This may cause [[Speedometer Error|speedometer error]]. As the tire [[diameter]] grows, the tire width decreases. This centrifugal growth can cause rubbing of the tire against the vehicle at high speeds. [[Motorcycle]] tires are often designed with reinforcements aimed at minimizing centrifugal growth.<ref name=":0A" />
* ''Pneumatic trail'': [[Pneumatic trail]] of a tire is the trail-like effect generated by compliant tires rolling on a hard surface and subject to side loads, as in a turn. More technically, it is the distance that the resultant [[Cornering force|force]] of [[Slip angle|side-slip]] occurs behind the geometric center of the [[contact patch]].<ref name="Clark">{{cite book|url= http://media.wiley.com/product_data/excerpt/19/04713546/0471354619.pdf |title=Mechanics of pneumatic tires |last=Clark |first=Samuel Kelly |publisher=U.S. Dept. of Transportation, National Highway Traffic Safety Administration, Washington, D.C. |year=1981}}</ref>
* ''Slip angle'': [[Slip angle]] or sideslip angle is the angle between a rolling wheel's actual direction of travel and the direction towards which it is pointing (i.e., the angle of the vector sum of wheel translational velocity <math>v_x</math> and sideslip velocity {{nowrap|<math>v_y</math>).}}<ref name=":0A" />
* ''Relaxation length'': [[Relaxation length]] is the delay between when a slip angle is introduced and when the cornering force reaches its steady-state value.<ref name=":0A" />
* ''Spring rate'': Vertical stiffness, or [[spring rate]], is the ratio of vertical force to vertical deflection of the tire, and it contributes to the overall suspension performance of the vehicle. In general, the spring rate increases with inflation pressure.<ref>{{cite web|url= http://www.engr.colostate.edu/pts/Job/Understanding%20Parameters%20Influencing%20Tire%20Modeling.pdf|title=Understanding Parameters Influencing Tire Modeling |first=Nicholas D. |last=Smith |date=2003 |publisher=Department of Mechanical Engineering, Colorado State University |archive-url= https://web.archive.org/web/20080920223731/http://www.engr.colostate.edu/pts/Job/Understanding%20Parameters%20Influencing%20Tire%20Modeling.pdf|archive-date=2008-09-20|url-status=dead|access-date=2014-11-23}}</ref>
* ''Stopping distance'': Performance-oriented tires have a tread pattern and rubber compounds designed to grip the road surface, and so usually have a slightly shorter stopping distance. However, specific braking tests are necessary for data beyond generalizations.<ref name=":0A" />