Genuine and 'Special' Chainset for Tern, 170 mm crank length, also can be used as an upgrade for Dahon Vitesse/Mariner D8 and any of the more basic models from Tern or Dahons like Speed/Vitesse D7's etc. Also suits as an upgrade for Dawes Kingpin, Dawes Jack and many other Dahon licensed technology bikes. Supplied with securing Allen bolts. This chainset does not have a guard but has a special Chainring developed to help prevent the chain derailling. Every other tooth is longer than normal and follows the pattern of one wider and then one narrower to allow for the outer and inner links of the chain.