Im doing my first build on an old raleigh tenspeed bike frame. I believe the rims are 26". I want to put some wider tires on it. Looking at other bikes that look like they have the same size rims it looks like they have 26" to 29" tires of different widths installed on them. My question is how can a 27,28,29" tire fit on a 26 inch rim/wheel and stay on?