Traction tires
The traction tire is a type of rubber ring that is located in a groove in the running surface of a drive wheel on model railroad vehicles .
purpose
The purpose of this arrangement is to improve the pulling force by increasing the coefficient of friction on the wheel .
Traction tires are mostly attached at the factory. Since they can cause the axle to wobble slightly and impede power consumption, most model vehicles only have one or two traction tires attached.
Problems
The main problem with the use of traction tires is their abrasion. This is deposited on the tracks and thus ends up on the wheels of other locomotives that use these tracks. In extreme cases, this means that the locomotives start to jerk after just a few minutes and the wheelsets have to be cleaned. This problem occurs in particular with two-wire direct current railways, as the (dirty) rails are used for power consumption. There are two ways around this problem:
- The models are not equipped with traction tires by the manufacturer. Even without traction tires, most model railroad locomotives from a certain minimum weight are able to move trains several meters long ( gauge H0 ). The prerequisite for this, however, is that all axes are driven. This principle is common in America (traction tires are completely unknown there) and has so far only been used by a few manufacturers in Europe for locomotives with more than 2 axles, e.g. B. in all models of Kleinbahn and most models of the Piko Hobby series.
- The models are designed in such a way that they can be operated with or without traction tires. The grooves for receiving the traction tires are dimensioned in such a way that it has no effect on the driving behavior if the traction tires are missing. Here, too, a certain minimum weight and all-axle drive are required. The locomotives from Roco , Piko and Mehano are usually constructed in this way, have a metal chassis and thus achieve the necessary weight.
- Locomotives, on the other hand, are problematic if they have such a deep traction tire groove that the wheel flange reaches down to the rail sleepers after the traction tire has been removed. This problem can only be dealt with by swapping the axes, which, however, requires specialist knowledge and special tools. If there is no all-axle drive, however, this is not enough, as the tractive force of the locomotive is greatly reduced. Using such locomotives, which are mainly offered by Fleischmann , can therefore be problematic on some routes.