The Tire Shrinker – Also known as an upsetter, was used to resize and weld buggy tires. When the hub and or spokes dried out from age and dry weather the outer band of iron called the tire would become loose. The tire could be heated and placed in this machine and then upset or squeezed leaving a bulge which was hammered flat and trimmed at the edges. The created a tire that was of a smaller circumference.
Repairing both wagon & buggy wheels and the shrinking & refitting of the tires was a common occurrence. Through natural wear the fellows (wooden piece(s) directly under the tire) of the wheel would wear and the tire would loosen which relaxed the “dish” in the spokes. If not repaired the wheel would shell out the spokes when a turn was made too fast with it. The spoked wheel is only strong if there is a dish toward the outside. This way when side pressure is applied to it during a turn a tight tire will prevent the spokes from bending sideways. Once the dish is lost, there is nothing to prevent this. A temporary cure that was often used was to soak the wheel(s) to make the wooden spokes & fellows swell and thus tightening the tire. This would eventually add to the wear of the fellows and loosen the tire even more. You can see old wagon tires that have been shrunken as they will have thicker spots where this was done. On a small wheel the circumference should be approx. 1/2″ less in the tire than wheel. For a tall wagon wheel the difference would be more. (Sometimes you would have to use the tire shrinker more than once to get the circumference that you needed.)
The shrunken tire was refit while hot. Simply heat the tire in a normal wood fire until when tapped with a hammer there was no more ring to the iron. It was then as large as it will get. You don’t want to fit the tire any hotter than necessary as it will want to burn the fellows. As soon as possible after getting the tire in place you would want to pour water over it to prevent damages to the fellows. (You can see the dish appear in the wheel as the tire cools.)
You can view this artifact when you visit our museum in the Old Blacksmith’s Shop