Antriebssysteme ohne Umwerfer: Unterschied zwischen den Versionen

image

====Einstellbare Kettenspanner====

Adjustable tensioners are set for the particular chain length/sprocket combination you will be using, and then tightened up to hold the pulley in the correct position. These are mainly intended for use on (yuck!) downhill bikes, and are designed to supplement a derailer to keep increase the chain tension, reducing the risk of accidental derailment.

Some, such as the no-longer-available Tektro unit shown above, are also useful for singlespeeds. If you have a pure singlespeed, without a flip-flop hub, this type is adequate, and may even be very slightly more efficient, because there is no spring loading on the chain. I (Sheldon) used to like the Tektro unit, but it proved a bit too delicate in practice, and clamping onto the chainstay isn't all that secure. A tensioner which clamps to the chainstay is not suitable for a bicycle with rear suspension and will very likely damage a carbon-fiber chainstay. I now prefer units that attach to the derailer hanger.

====Kettenspanner mit Federvorspannung====

These are like partial derailers, with a single spring-loaded pulley. They attach to the derailer hanger of your dropout, or to an adapter claw. Like many purpose-built singlespeed parts, they are often rather expensive considering how simple they are. If you plan to use different gear ratios, for instance with a flip-flop hub, a spring-loaded tensioner is the best choice.

====Wiederverendete Schaltwerke====