Bicycle wheel some other fixed point may be used as a reference mark, however this is less accurate. At one end of each spoke is a specialized nut, called a nipple, which is used to connect the spoke to the rim and adjust the tension in the spoke. The nipple is usually located at the rim end of the spoke but on some wheels is at the hub end to move its weight closer to the axis of the wheel, reducing the moment of inertia. Until recently there were only two types of nipples: brass and aluminum (often referred to as "alloy").
Ferris wheel as a triple Ferris wheel, Triple Giant Wheel, or Triple Tree Wheel, it was in height. The Santa Clara ride, renamed Triple Wheel in post-Marriott years, closed on 1 September 1997. The Gurnee ride closed in 2000. An eccentric wheel (sometimes called a sliding wheel or coaster wheel) differs from a conventional Ferris wheel in that some or all of its passenger cars are not fixed directly to the rim of the wheel, but instead slide on rails between the rim and the hub as the wheel rotates. The two most famous eccentric wheels are Wonder Wheel, at Deno's Wonder