The dynamics of mobile ad hoc networks, as a consequence of mobility and disconnection of mobile nodes, pose a number of problems in designing routing protocol for effective communication between the source and destination. In this paper, we proposed a radio-link adaptive mobile ad hoc routing protocol which adapts to time-varying network topology and radio channels. A novel estimation method based on accumulating the practically obtained signal-to-noise ratios and an adjustable weighting parameter, named as Forgetting Factor, is proposed to represent the stability of radio links. From the estimation of radio link stabilities, the proposed protocol further evaluates the route stability of each eligible multi-hop route and the route with the best stability is selected for a specified source and destination pair. Our simulation results indicate that the proposed routing protocol improves up to 180% of data throughputs and decreases 80% of route breakage time comparing to the well-known Ad-hoc On-demand Distance Vector routing protocol.