So you would like to ride your favorite bicycle indoors? The Tacx Antares Indoor Retractable Bicycle Rollers have you covered. They have conical rollers to keep the the wheels centered. This indoor trainer fits bikes with 26 to 29″ wheels. It folds down to 31.5” x 18.5” x 5.31″ for easy storage.
You can try stand up riding on this trainer too. More info is available here.