My cousin was using this bike for 2 years.
Recently he sold it, and I asked him why did he sold the bike.
He said he was not satisfied with the bike and continuous chain problems make him to sold the bike.
Even I rode this bike 3 to 4 times, while riding at 60kmph there is a sound came from the chain and I rode slowly to avoid the sound.
He even said instead of chain problem everything is perfect with the bike.