Using the home oven for preheating
Today a week later I made another idler wheel that is much better and easier to fabricate
On my rims welded a ring of 6mm round bar then the rim and tyre placed them in to a stainlesteel tray and in to the oven,set temp to 120 C with themofan on heated them for 20 min. Check if the tyre getting soft,then increase temp to 150 C again check and increase to 170 C,
at this setting the tyre becomes soft like Dow.get your self a good pair of heat resisting cloves and,
Try to fit the tyre over the rim using a screw driver and pressure if the tyre gets hard back to the oven for 10 min then try again and again until you stretch the tyre over the rim.
I stretch my tyre over 15 mm in diam,as you can see i was very hard trying to see if it will tear off but this is very hard and never break.
I made a bigger adjustable collar 180mm and place some thin sheet from a can that i cut open and back to the oven for 15 min at 170 C You can close the collar and use extra heat from gas torch to heat the rim until the tyre melts against the metal surface if the collar is hard to adjust place it back to the oven and try again until you have a uniform over flow of the tyre
This idler wheel is made 135mm closer to the scale and no mater if the tyre separates it will never come out .
With this wheel i can go up to 40Km/h and not to worry for any tyre separation.
A jig will be made to fit the tyre over the rim,
With this process you can expand or sring the tyre more then 15mm with no effect on strength.