if you have taken the MSF safety course, then there is nothing wrong at all with the 650… remember its a p-twin engine not an inline. Many of the folks here would recommend an SV650 to a beginner (albiet a beginner who is comfortable on two wheels)… and in my opinion– the ninja 650 is more noob friendly than even that bike (because of a smoother throttle and less HP).
Both the Ninja 650 and SV650 CAN overwhelm a completely new rider… but again, if you really like the 650 over the 500- its really not that big of a jump.
Some people on here are making the ninja 650 sound like its a Hayabusa… However, I haven’t spent anytime on a ninja 500…so I am in no way shape or form an expert. I’m curious to those who have rode both the 500 and 650… how much performance does the 650 REALLY have over the 500.
All I know is that the 650 feels more comfortable to me, the throttle is very smooth, and the suspension is very forgiving. I have never felt like my 650 could ever wheelie on me… (that isn’t to say that it can’t be done… I guess I just don’t have the skill); and its my belief that unless you drive like a moron (or are just jumping on a motorcycle literally for the first time) the 650 isn’t likely to get you into trouble.
with that said…. if you are driving in anger (like a moron)… I’m pretty sure you have a strong chance of having a bad day. But its not the same as a green rider jumping on a CBR1000– where even if they are level headed, they have no skill set to control the bike; that is vastly opposed to the 650 which is a very controllable bike (IMO).
if you want to constantly rev your bike at 11k RPM and showboat around… Forget even the 500 and get a 250; cause even that 500 will get you in trouble.