Tire Shrinker

I don’t completely understand this video.  It appears to me to be just the first of two necessary steps.  In this first step the tire is made smaller more by buckling than upsetting.

https://www.youtube.com/watch?v=xubuFXZDpA0

It seems the second step should be to take another high forging heat at the buckle.  The lock the tire in the shrinker with the buckle directly over the anvil plate and forge the buckle flat and smooth.  The grip of the dogs prevents the forged segment from growing laterally, the hammering brings the tire back to proper dimensional thickness.  The tire does grow some in width and that can be removed by filing after the tire has been placed back on the wheel.

I looked through some of my old photo files and couldn’t find an image to the machine once owned.  A Google image search brings up a number of similar ones.  I’m just beginning to recover from what I presume was the flu apparently not prevented by my flu shot, so, I have no energy to pursue it further at this time.

My Tire Bender

About 15 or 20 years ago I found a tire bender in a flea market in really good shape, except for a missing crank handle, and soon after found a tire (or tyre) shrinker in a tailgate sale frozen with rust.  I bought both of them thinking they might be nice antique display items.

With penetrating oil, heat, force and time I got the tire shrinker apart, cleaned and in good working condition.  After it sat around a couple of years I got an offer I couldn’t refuse so I let it go.  The tire bender worked well for making large rings and I used it a few times before it became a permanent fixture on the porch.  It is one of a number of things I need to get rid of this year to make space.

Both of these tools served wheelwrights well.  The American one-piece tire was made like this.  The wood wheel perimeter was measured with a traveler and wrought iron of the appropriate width and length for the tire was forged.  The ring of the tire was created with the bender and the junction was forged welded.  The tire should be just a bit too small to fit the wheel cold but when heated it could be slipped on and quickly cooled with bucket after bucket of water shrinking and seizing around the wood.  I’ve seen videos of this but never actually attended a live fitting.

I once visited a historic site where just out side the wheelwright shop there was a foot deep circular pit where a corncob fire was started and used to heat the entire circumference of the tyre.  Next to it was a a worn out granite mill stone about six or seven feet in diameter where the wood wheel rested waiting for the fitting.  Buckets of water would be placed around the stone ready for dumping.

This video shows a more modern version of the process.

https://www.youtube.com/watch?v=k0gPGoz9Xhc

The shrinker was used when a tire needed to be made smaller.  After some use the tires would fret on the wood and wear it away and loosen.  The tire could be knocked off and heated to forging temperature for several inches in an area which might have already been a bit thinned.  When placed in the shrinker the dogs would grip the tire and upset it or buckle it slightly over an anvil plate and the tire would be hammered smooth again.  When it was appropriately too small the whole tire could be heated and placed back on the wheel and cooled.  I’ve never actually witnessed that either.