More torque

[RadenRider26]

Hi guy I want more torque on the ninja 250r 2010 carbo, an advice on engines mod. I was think of changing the cdi???

[Motofool]

Install a bigger rear sprocket.

That way, you will have a reduced final speed, but higher torque for start-ups, going uphill and carrying a passenger or heavy loads.

[RadenRider26]

Originally Posted by Motofool

Install a bigger rear sprocket.

Ok what size??? and brand good???

[dcj13]

Does anyone put on a 13-tooth front sprocket? Do they even manufacture them?

[SLOWn60]

Originally Posted by dcj13

Does anyone put on a 13-tooth front sprocket? Do they even manufacture them?

Yes. I run a 13:47 (both steel)
It's mostly for track days but it's great in the city too!
JT Sprockets makes them for the 08-12 250R

[Somchai]

Sorry guys to contradict you, but you're talking about gear ratio and not torque.
Torque means power from/in the engine and more torque is possible i.e. with advanced ignition or different camshafts and for sure also with more cc...

[RadenRider26]

Originally Posted by Somchai

Sorry guys to contradict you, but you're talking about gear ratio and not torque.
Torque means power from/in the engine and more torque is possible i.e. with advanced ignition or different camshafts and for sure also with more cc...

Somchai, what i change the CDI.

[Ghostt]

Torque is torque, changing the gearing doesn't increase or decrease that.

The gears in your transmission are torque multipliers, and the final-drive ratio of your countershaft and rear sprockets also have an effect on torque. Changing the final-drive ratio is one of the easiest ways to modify the feel, acceleration and top speed of your bike. Lowering your gear ratio with the popular down one tooth in the front and up two teeth in the rear (-1/+2) sprocket set makes a huge difference on how the bike accelerates off the light.

Changing the CDI will not do much, the reality is it's a twin parallel 250, if your looking to unlock some huge magic, it's not there, Kawasaki did all they could and pushed the engine to its limits as it is, if you want more torque/hp, get a bigger bike.

[RadenRider26]

Originally Posted by Ghostt

Torque is torque, changing the gearing doesn't increase or decrease that.

The gears in your transmission are torque multipliers, and the final-drive ratio of your countershaft and rear sprockets also have an effect on torque. Changing the final-drive ratio is one of the easiest ways to modify the feel, acceleration and top speed of your bike. Lowering your gear ratio with the popular down one tooth in the front and up two teeth in the rear (-1/+2) sprocket set makes a huge difference on how the bike accelerates off the light.

Thanks Ghostt I will tell to change it when i get to service

[Ghostt]

The best investment is putting your money into the suspension.

[RadenRider26]

Originally Posted by Ghostt

The best investment is putting your money into the suspension.

What kinda matre sorry i new to road bike automatic scooter, i can tell you all about it. road bike i no god dam clue (sorry using god name in vain)

[Ghostt]

Originally Posted by RadenRider26

What kinda matre sorry i new to road bike automatic scooter, i can tell you all about it. road bike i no god dam clue (sorry using god name in vain)

It depends on how much you weigh?

There are number of things you can do, but it all depends on your weight. Odds are the rear shock is fine, the weak link is the front fork springs, they are weak compared to the rear shock, this causes the bike to be unbalanced, as far as the suspension is concerned.

[RadenRider26]

Originally Posted by Ghostt

It depends on how much you weigh?

There are number of things you can do, but it all depends on your weight. Odds are the rear shock is fine, the weak link is the front fork springs, they are weak compared to the rear shock, this causes the bike to be unbalanced, as far as the suspension is concerned.

I weight 95kg (big rugby boy), yes i already replaced my front shock once and had to change the springs 3 month ago due to a little crash on the road. so what do i need to to the front shock

[Ghostt]

Here is an excellent write-up on the Ninjette suspension by @InvisiBill

I've done quite a bit of research and played around with a few different options on my 500, but definitely listen to the guys here who actually have real-world experience on these bikes.

Getting the spring right for your weight will allow the bike to bounce the proper amount. That allows the damping to have the best control over that movement. If your spring is too soft, it will bounce around too much and your damping system will have to work harder to try to constrain that extra movement. If the spring is too stiff, it won't compress enough to absorb bumps, and the wheel will skip. http://www.ex-500.com/wiki/index.php...ension_Preload is a long read, but it has tons of info, and I think it does a good job explaining everything with examples.

According to RT's calculator, the rear spring is ideal for someone who weighs 220lb (100kg). People here have said that may not be exactly right, but the spring is definitely quite stiff compared to the other little Ninjas (it's 73% stiffer than the 500 spring). I'm assuming you're lighter than that, so going to a softer spring should make the rear work better for you. The PreGen's spring is good for about 140lb on a NewGen, but the shock is a little shorter so it would lower the rear and make the handling a bit slower (plus it lacks any preload adjustment). If you can find a decent one cheap on eBay, it might be worth tossing one in just to try it out though (they're usually ~$20 here).

The stock shocks are simple, non-adjustable, non-rebuildable, lowest-bidder units. Aftermarket shocks give you more adjustment options for tweaking the damping system (usually separate for compression and rebound) and are built with higher quality, replaceable parts (so when something wears out on it, you just replace that one part instead of buying a whole new shock). £395 is US$615 which seems somewhat expensive to me. A new Penske is about $800 here, and used ones can be half that. The nice thing about buying a new shock is that they generally include a spring and calibration to match your weight. It should be basically a perfect drop-in upgrade.

If you can do a bit of mod work, the GSX-R shock swap is a pretty cheap way to get a decent shock, and there are a variety of spring rates used on the various models (there's a chart of different rates/weights toward the end of the thread). It's not made specifically for the Ninja's suspension, and requires a bit of work to make it fit, but they're usually on eBay for about 1/10 the cost of that Brook shock. The SV650 shock doesn't have all the adjustments (it's comparable to our stock shock) but should require less work to install, as another cheap DIY option that's probably more suited to your weight.


NewGen Fork Spring Rate Chart
Again, the NewGen has the stiffest fork springs of the little Ninjas. It's still a tad low, but should be acceptable if you're smaller. If you're a fatty like me, it's still quite a ways off, but it is possible for it to match up fairly well to the weight of a smaller adult (unlike the PreGen and 500, which have essentially useless fork springs).

The stock front and rear are pretty mismatched, so if you're smaller and go with a lighter rear spring, you're actually reducing that mismatch and making it less-bad than stock. On the PreGen and 500, replacing a soft rear spring with something appropriate can exacerbate the problems of the super-soft fork springs (because you're increasing the mismatch).

__________________________________________________

*** Ghostt, I'm not your mom and I'm not paying for your parts, so do whatever you want with your own bike. ***

[Motofool]

Originally Posted by Somchai

Sorry guys to contradict you, but you're talking about gear ratio and not torque.
Torque means power from/in the engine and more torque is possible i.e. with advanced ignition or different camshafts and for sure also with more cc...

Any time that the output gear (rear sprocket) has more teeth than the input gear (crankshaft), then the gear/sprocket train amplifies the input torque and reduces rotational speed.

As power (HP) is the product of torque (rotational force) and rotational speed (rpm), it remains the same though the gear/sprocket train (actually, some power is lost along the train due to friction).

Of course, increasing the power that the engine generates, the output torque (force on the rear contact patch) increases as well, for the same transmission ratio.

https://www.ninjette.org/forums/show....php?p=1035290

https://en.wikipedia.org/wiki/Mechanical_advantage

[RadenRider26]

Originally Posted by Motofool

Any time that the output gear (rear sprocket) has more teeth than the input gear (crankshaft), then the gear/sprocket train amplifies the input torque and reduces rotational speed.

As power (HP) is the product of torque (rotational force) and rotational speed (rpm), it remains the same though the gear/sprocket train (actually, some power is lost along the train due to friction).

Of course, increasing the power that the engine generates, the output torque (force on the rear contact patch) increases as well, for the same transmission ratio.

https://www.ninjette.org/forums/show....php?p=1035290

https://en.wikipedia.org/wiki/Mechanical_advantage

can you explain in idiot treams

[Motofool]

Originally Posted by RadenRider26

can you explain in idiot terms?

What part?

There is linear movement and rotational movement.

For linear movement, we have linear speed (the bike moves forward) caused by linear force (contact patch of rear tire pushes the pavement backwards; as pavement does not move, the reaction makes the axis of the wheel move forward).

Hence,
Linear speed x Linear force = Power (HP)

For rotational movement, we have rotational speed (the rear tire rotates) caused by rotational force (torque reaching the rear tire).

Therefore,
Rotational speed x Rotational force (torque) = Power (HP)

The amount of maximum power (HP) that your engine can generate is limited.
Because of that, you can only play with the two terms of the equation.
If you want more speed, you must sacrifice force or torque and vise-verse.

As you want more torque on the ninja 250r, your only practical option is making the rear tire turn more slowly.

If what you wanted was more HP, then you have to increase the pressure inside the combustion chamber.
However, there is no much more that you can do about it.

[RadenRider26]

Originally Posted by Motofool

What part?

There is linear movement and rotational movement.

For linear movement, we have linear speed (the bike moves forward) caused by linear force (contact patch of rear tire pushes the pavement backwards; as pavement does not move, the reaction makes the axis of the wheel move forward).

Hence,
Linear speed x Linear force = Power (HP)

For rotational movement, we have rotational speed (the rear tire rotates) caused by rotational force (torque reaching the rear tire).

Therefore,
Rotational speed x Rotational force (torque) = Power (HP)

The amount of maximum power (HP) that your engine can generate is limited.
Because of that, you can only play with the two terms of the equation.
If you want more speed, you must sacrifice force or torque and vise-verse.

As you want more torque on the ninja 250r, your only practical option is making the rear tire turn more slowly.

If what you wanted was more HP, then you have to increase the pressure inside the combustion chamber.
However, there is no much more that you can do about it.

Ok, i think i understood that. i was talking to my friend the other day an other bike lover and he was talking about changing the air filter, crabo, spark plugs and icu. he said that will give more torque with out loosing to much of my top speed.
do this sound about right to you guys?