Although the Bajaj Avenger Street 150 comes with cushioned seats but yes there have been many complaints about the discomfort while riding. This is due to the improper positioning of the handlebars, seat and foot-peg. The handlebar are too far off from the rider. In case, the rider sits within the contours of the seat by placing his legs on the foot rest then a lot of stretch is required in order to reach the handlebar. This is a major reason of discomfort which has caused back pain. Try sitting slightly closer to the tank which may even cause a bit of discomfort but still help in easing pain.