Can you make a ninja 250 look cool?

[John]

You should get an EX500 instead.

lol you are funny

[NinjaNick]

No, you cant make a 250 look cool

and on your top speed question unless you are limited in speed by the gearing you may actually increase your top speed when gearing down as you will be at a higher RPM when at the same MPH. For most bikes higher rpm = higher hp.

Gearing is a blast to play with!

Lots of top speed racers gear the front UP and the rear DOWN for that.

My bike is 17/41 stock. I have 16/43 now which adds more acceleration, but less top end. Some of the top speed guys will maybe go 17/39 or 18/40, etc...to gain more top speed.

[NinjaNick]

Redkow - www.gearingcommander.com check it out. You'll have hours of fun with it.

99.9mph on a Ninja250 1988-2005 at 12,300rpm with 14/45 stock gearing; take away a few mph.

Edited March 8, 2011 by NinjaNick

[Jst2fst]

I rode a 250 once..... I was literally looking for the pedals when I hit a hill with it.

I've never had the privilege to ride one thank gawd.

[redkow97]

Redkow - www.gearingcommander.com check it out. You'll have hours of fun with it.

99.9mph on a Ninja250 1988-2005 at 12,300rpm with 14/45 stock gearing; take away a few mph.

but that's only a theoretical calculator - it doesn't account for wind resistance.

Gearing a bike up only works if you still have extra power on tap. You can't gear an EX250 to hit 120mph any more than you could gear a civic to hit 200mph. At a given speed, the horsepower at the wheel is equal to the force of the wind pushing back. Changing your gearing doesn't change how much power you're putting to the ground, just what RPM you're at when you achieve equilibrium with the wind.

[shittygsxr]

but that's only a theoretical calculator - it doesn't account for wind resistance.

Gearing a bike up only works if you still have extra power on tap. You can't gear an EX250 to hit 120mph any more than you could gear a civic to hit 200mph. At a given speed, the horsepower at the wheel is equal to the force of the wind pushing back. Changing your gearing doesn't change how much power you're putting to the ground, just what RPM you're at when you achieve equilibrium with the wind.

If you get all of that why don't you get how gearing down a lower HP bike can increase top speed?

[ReconRat]

There's no way in hell any ninja 250 is hitting 120 unless it's hit from behind by a corvette.

And weight has almost no affect on top speed. It has a dramatic affect on acceleration, but not on top speed. Top speed is determined by aerodynamics and horsepower. An EX250 has like 28hp(?), so whenever the wind is pushing back with the force of 28hp, you've reached top-speed for that bike.

a 200 lbs rider and 80 lbs rider both still only have the same 28hp on the same bike - the only difference is that the 200lbs rider might be SLIGHTLY less aerodynamic; but that's based on surface area, not mass.

Agreed. But I think most heavy riders aren't willing to wait a few hours to accelerate to see what that top speed is.

edit: I went with the 120mph since it's a nice round number and the internetz seems to think a 250 will do it. None of my small bikes ever did. I was lucky to get 95mph. I do remember going up one tooth in the front on a small bike, it actually went slower. It didn't like that at all.

Edited March 8, 2011 by ReconRat

[NinjaNick]

122mph

http://www.youtube.com/watch?v=JvDBfdhyS_U

[SpeedTriple44444]

I rode a new Ninja 250 home for a friend's son the other day. I was afraid for the 1/2 mile of highway riding I had to do... thought it would never get to 70 (but I'm 250ish with gear, so the little thing was grunting). Otherwise, it wasn't too bad. It would be a fun little around-towner.

[ponyjr]

-pipe

-pod filter

-rejet/jet kit

-reasonable tires (no stock size because no one makes a "good" tire set in those sizes)

-re-gear

-digital dask (i.e trailtech, Koso, Electrosport)

-dual sport head light

-motorcross bars

-lots of black paint

should make a pretty awesome bike. I've ridden a stock ex250 and i toted me around a parking lot plenty fast and is still faster than most cars.

[redkow97]

for those who didn't watch the video, the 122mph ninja 250 needed nitrous to get there.

Plus the bike didn't have mirrors (that's a significant source of drag) and they had a more aerodynamic tail on the bike, not to mention what looked like a 15 yr old girl riding it. She's going to get in behind the fairing a lot better than most people (notice I didn't say anything about her being light, because it doesn't matter)

It also appeared that they weren't running a front brake for some reason - better acceleration, I assume, or just less un-sprung weight.

[redkow97]

If you get all of that why don't you get how gearing down a lower HP bike can increase top speed?

because gearing down doesn't increase horsepower.

If the bike is running out of gear before it runs out of power, then yes, gearing up will increase top speed, but that's not the case with a 250.

It runs out of power before it runs out of stock gearing. Gearing down will only cause it to run out of RPM at a lower speed, not a higher speed.

Think of it in human terms - on a 21 speed bicycle, if you're chugging along as fast as you can possibly go in 21st gear on flat ground, another gear isn't going to make you go faster, it's just going to make your legs work harder - you already can't pedal any faster because the resistance is matching your legs' strength.

The same is true of an engine. An extra gear doesn't magically give it more power, and thus more top-speed. It max X horsepower at Y RPM. Once the force of the wind = X horsepower, you're done. the only way gearing down would make a bike faster is if you weren't able to get to Y RPM, which I think would be exceedingly rare - maybe even impossible.

Look at the bonneville salt flats times. If all you needed to do was re-gear bikes, no one would be bothering with power adders.