How to keep traction tires on ?

Once they start falling off, they are stretched and will not stay on.

The only cure is to replace them with new ones.  Perhaps your installation technique is faulty.

The trick is to not overstretch the new ones when you put them on the wheels. Instead of treating them like rubber bands, you should think more like mounting a car tire on a rim. I use three tiny screwdrivers to put them on without stretching. You almost need three hands to do this, but you can get used to it eventually.

For one thing, do NOT use GooGone to clean your track!

Thanks RoyBoy for your approach.  I always try to replace the one that came off and do approach the replacement of the old tire like its is a rubber band.

Make sure you clean the groove in the wheel before you put the new traction tire(s) on. I use alcohol and a Q-tip.

Use a drop or two of regular(non-gel) CA/Eastman 910/SuperGlue to secure the tires on the wheels... it will seep around the circumference by capillary action very quickly, cure fast, and extend the life of the tire - almost indefinitely until it actually wear through.

CA has excellent tensile strength, but poor shear strength, allowing you to remove or replace the tires quite easily by breaking/chipping off the old tire & glue.  Easiest done upside down in a cradle with the loco running using an appropriate sharp tool(good screwdriver, eg.).

Roll them on and do not expand them.  If done right they will not come off.  Do not use glue of Bull Frog s___.  As the tire goes around the layout it will settle into the grove properly and give you a smooth engine.  If done properly, they will last for years.  I still have engines on the layout that are over 20 years old with the tires still in good condition. My trains get run very often.

Guys have methods they use that work for them and that is good.  What I mentioned works for me.