Look at the ¼-mile and 0–60 times and I think you’ll see what doubling the displacement will do for you.

The relationship between torque, power, and performance is a bit complicated, especially once you throw gearing into the mix, but I’ll try to simplify it.

First off, HP = ( FootPoundsTorque * RPM ) / 5252

Second, thanks to aerodynamic drag, all else being equal, the relationship between HP and top speed is exponential; doubling HP will **not** double your top speed.

A smaller engine gets most of it’s power from RPM while a larger one gets more from torque (foot-pounds). It’s brute force (foot-pounds) that makes you accelerate, but that is also affected by gearing. That is why some Honda Civics rev higher and have shorter final drive ratios than most cars; they make a lot of HP but little torque, and they make it up in gearing.

Higher HP will allow you to gear down and supply more acceleration at the same speed *or* maintain the same acceleration and go faster. Given the respective top speeds of those two bikes and peeking at the numbers I think you will notice a difference in “punch”. If the gearing were the same then the top speeds would have a wider gap but since they don’t then the only logical conclusion is that the 500 is geared lower for better acceleration. More torque from the engine plus lower gears equals better acceleration *and* easier cruising.

The 500 will also have an easier time cruising at 70 MPH since the engine won’t be working as close to it’s limits as your 250, especially not if the gears are matched to the power curve of the engine which they seem to be. Odds are that your tach readings will be lower at a given speed with the 500 than with the 250, and you’ll have more twist left in your throttle grip.

I would still recommend a test ride if possible, but I don’t think you’ll be disappointed, and you *definitely* won’t be shocked like you would be with the 600R. It’s not so much the extra 100cc in that case, but more that the 600R is a different breed of bike. There is a reason that it costs twice as much as the 500; the same reason an Evo costs twice as much as a regular Lancer.

I’m not saying don’t do it, but I **strongly** recommend that you learn to walk before you run and take things one step at a time. Besides, if you treat that 500 right then you will have a decent trade-in when you are totally ready for a 600R in a couple of years.