Chain guide device

摘要

The present invention relates to a chain guide device (10) for gravity or all-mountain bicycles comprising a frame (11) and a toothed chainring (12) on which the pedals are mounted. The chain guide device (10) is intended to be positioned coupled with the chainring (12) in such a way as to prevent the chain (14) of the bicycle from coming off the teeth of the chainring (12). The chain guide device (10) comprises: a top guide (20) intended during use to be positioned along the top portion of the chainring (12) and provided with a first groove (22); a bottom guide (30) intended during use to be positioned in the vicinity of the bottom portion of the chainring (12) and provided with a second groove (32); said top guide (20) and said bottom guide (30) being arranged on a support (40) by means of which the chain guide device (10) is fixed to the frame (11) of the bicycle. In accordance with the invention, the first groove (22) and the second groove (32) interact directly with portions of the chain (14) which are directly engaged with the chainring (12), coming into contact with the chain only if the chain tends to disengage from the teeth of the chainring.