Glue in the braces
Check the fit of your braces in the wheel slots. They should all be flush with the edge of the wheel.
Glue in each brace and secure them till they dry. I use just a piece of rope or strapping. Basically whatever I have lying around. You can even do it with heavy twine. Just wrap around the outside to keep them from falling out. I usually use liquid nails for projects like this because of it's gap-filling qualities.