Quick release skewer
From Wikipedia, the free encyclopedia
A quick release skewer is the rod, threaded on one end and with a cam assembly on the other, a part of the quick release mechanism, a lever operated cam system used with a hollow axle for securing the wheels on a bicycle. Wheels equipped with quick release mechanisms can be removed from the bicycle frame and replaced without using tools by opening and closing a lever, thus more quickly than wheels with solid axles and hex nuts. On the negative side, a quick-release hub renders a wheel more vulnerable to theft. Also, care must be taken to ensure that the mechanism is properly tightened.
Similar quick-release mechanisms are also used to operate seatpost clamps.
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[edit] History
The mechanism was invented in 1927 by Tullio Campagnolo, an Italian bicycle racer, He was frustrated when he needed to repair a flat tire during a race. The weather had turned cold, and his hands were numb, so he could not operate the wingnuts which retained the wheel. He had been well-placed prior to the puncture, but lost valuable time. Another Campagnolo invention that made use of the quick-release mechanism was the Cambio Corsa, a multi-gear changing system consisting of a rear wheel quick-release lever with a mechanical extension that placed the lever itself near the bicycle's saddle, combined with a fork that served as a primitive version of a rear derailleur (without idler pulleys to take up slack), that also had a control lever near the bicycle saddle. This innovation enabled bicycle riders quickly to change gears while in motion by releasing the axle, moving the rear wheel slightly forward by applying tension to the chain, actuating the fork to change to a larger sprocket, and tightening the quick release again; or else releasing the axle, actuating the fork to change to a smaller sprocket, moving the wheel slightly rearward by braking, and tightening the quick release again. The quick-release mechanism, along with other innovations and high standards of manufacture, enabled Campagnolo to become a leading road cycling and track cycling component manufacturer.
[edit] Usage
Quick releases tend not to be used on certain types of bicycles, such as utility bicycles (with a single speed or hub gears) or track bicycles, partly because of tradition and partly because there is less need for quick removal of wheels without using tools.[1]
Quick releases are sometimes recommended against with the use of disk brakes because of the need for the axle attachment to withstand braking forces.[2][3]
In response to liability issues because of a few riders losing front wheels while riding because of incorrect use of quick releases, the CLIX wheel retention system has now appeared on the market.
[edit] References
- ^ Singlespeed Conversions - Solid-Axle vs Quick Release. Retrieved on 2007-01-18.
- ^ Disk brakes and quick releases - what you need to know. Retrieved on 2007-01-18.
- ^ Technical Q&A with Lennard Zinn - Funky Disco Drop-out. Retrieved on 2007-01-18.
