All About Bicycle Chainline Chainline This refers tohow straight the chain runs between the front and rear sprockets .Ideally, both sprockets should beinthe same plane, sothat there isnosideward motion orstress tothe chain. This constitutes "perfect chainline". Inthe case ofderailer geared bicycles, the chainline isnot perfect in most gears. The worse the chainline, the worse the mechanical efficienty ofthe drive train. "Correct" chainline for aderailer system isamatter ofopinion, and depends onthe intended use ofthe bicycle. There are two "simple" answers tothe question ofwhat constitutes proper chainline: view isthat the middle ofthe cluster should line upwith the middle chainring (or half-way between the two, inthe case ofa double . the parts manufacturers' point ofview, the chainline depends onthe diameter ofthe seat tube where the front derailer mounts. For fatter seat tubes where the front derailer isfarther tothe right, derailer manufacturers want the chainline tobefarther tothe right also, because their main priority isshifting performance, and their front derailers have anoptimal chainline with respect tothe edge ofthe seat tube. This isparticularly aconcern inthe case ofbicycles with indexed front shifting. From the rider's point ofview, chainline ispartly dependent onhow you are going touse your gears. For instance, consider aroad triple vsa mountainbike triple: ?With aroad triple, you mostly use the two bigger rings, the granny isonly occasionally used, and only with the larger rear sprockets. For aroad triple, having the cranks close-in isgood, because itincreases the usability ofthe big ring. ?With amountain bike, the small ring isused much more often, and must often beused with fairly small sprockets toavoid having toshift the front under load. For mountain bikes, amore outboard chainwheel position isoften preferable. Chainline Standards: Application Dimension Notes Road Double Shimano spec, measured to the midpoint between the rings.
自行车链条线设计参数 来自淘豆网m.daumloan.com转载请标明出处.
