Let me give you a quick review on this. I bought this bike on June 29th, 2016. This it was my biggest mistake. This bike is for turning you into a hater. Firstly this bike is not at all confortable, it will give you a sever back pain. The seat is so small that it will effect your hip bones. The handle bar will cause wrist pain. Last but not the least, gears will make you feel like you are riding a defective bike. shimano gears are the known to be the best in the world, but in this bike I guess they installed shimano's most cheapest derailleurs.
Please don't waste your money in this bike. Go for the better one. Don't fall for it's looks.
Thank you for taking the time to give us your review. Apologies for the bad experience you have had with the bike. I would like to know if you are a beginner cyclist and how much distance you would ride in a day. These factors are important in choosing a bike. In a Leisure MTB like the rockrider 340 the frame is of a sport geometry. Which means you back will be angled towards the handle bar and the seat will be small. The Bike is designed for rugged conditions so it will perform well on our roads. If you are riding everyday and comfort is the important thing for you to look at, you will need a city hybrid bike. (http://www.decathlon.in/p/8165507_original-500-hybrid-bike-grey.html?search_query=original+500&r...) . It has wider seats with gel and an adjustable handle bar for better positioning.
The derailleur on the rockrider 340 was the TZ-30 which is a very basic derailleur of Shimano. We received negative feedback from our users and now it's upgraded it to Shimano Tourney. Since this change, the feedbaack has improved. It is possible that the tuning is off on your bike and our workshop will be able to fix that when you bring it for you first free check up.
Deepak Babu E-sport manager DECATHLON