I would have to say that if you purchase a bigger bike just to keep up with your friends and you are a new rider/inexperienced, you should find new riding friends. Or at least make them understand that by pressuring you will find the group with one less rider with the possibility of loosing a friend in a crash. I have friends that would ride fast as they were experienced but I hung back, rode my own bike and enjoyed the ride. If they, the other riders, don't get it, the new rider with the inexperience will most likely pay the price. Ride smart, gain experience and enjoy the ride!