There are no bike shops within a day's drive. The graded scenic road is generally suitable for passenger cars. With that in mind, be alert to motorists and tour operators. The route may be very warm, so carry plenty of water. And don't forget the sunscreen.
Motorists are frequent on the scenic drive.
You might hitch a lift with a tour operator, but expect to pay a fee for services rendered. Goulding's Trading Post has medical facilities. The park entrance is 3 miles to the east. Park at the visitor center. Get Adobe Acrobat.