DIY- Sprocket Swap

[Alex]

No, not on our ninjettes. The speedometer is driven off of the front wheel, so any gearing changes have no effect. This is rare, as in most bikes the speedometer is driven off of the transmission output shaft, so any gearing changes do have an effect.

[headshrink]

EDIT: Oops... Alex got there first.

[jack_bm]

Ohh thats intresting to know thought i was gunna have problems if i was to change the sproket, next question how much would putting a 47t as the rear affect teh top end speed?

Haha thanks for the replys though

[Alex]

www.gearingcommander.com

[flynjay]

Originally Posted by jack_bm

Ohh thats intresting to know thought i was gunna have problems if i was to change the sproket, next question how much would putting a 47t as the rear affect teh top end speed?

Haha thanks for the replys though

Not really much you can do to change the top end speed (except lower it of course). The ninja is power limited, so you will run out of motor before you run out of gear.

With the 47 rear you may be able to get to the red-line in 6th gear.

[jack_bm]

Originally Posted by flynjay

Not really much you can do to change the top end speed (except lower it of course). The ninja is power limited, so you will run out of motor before you run out of gear.

With the 47 rear you may be able to get to the red-line in 6th gear.

ohh thats cool with faster acceleration right?

[CZroe]

Originally Posted by Alex

Is that edit correct at this point?

Looks good to me. Thanks, Alex!

Edit: I see we lost our PDF though. Just waiting on confirmation?

[choneofakind]

Originally Posted by jack_bm

ohh thats cool with faster acceleration right?

yes. I like my 14/47 setup. just a little quicker to redline, nothing insanely 600cc-esque.

makes me

[flynjay]

Originally Posted by jack_bm

ohh thats cool with faster acceleration right?

Yes. The downside is you will be ~11k rpm at 75mph. Pay particular attention to your oil consumption.

Faster acceleration also means quicker shifting.

I ride the highway quite often, so I prefer the 15/45 setup.

[choneofakind]

more like 10,000 http://faq.ninja250.org/speed/#noredir

solution. Ride back roads.
another solution. Ride at 70 instead of 75. That's 9500 rpm

[jack_bm]

Originally Posted by flynjay

Yes. The downside is you will be ~11k rpm at 75mph. Pay particular attention to your oil consumption.

Faster acceleration also means quicker shifting.

I ride the highway quite often, so I prefer the 15/45 setup.

Woahh is that in gear 6 as well?

[flynjay]

Originally Posted by jack_bm

Woahh is that in gear 6 as well?

Yep. Plugged your info into the gearing commander website and you will be around 10K at 75mph.

I run 8.5K at 75 with 15/45 gearing.

[jack_bm]

Originally Posted by choneofakind

yes. I like my 14/47 setup. just a little quicker to redline, nothing insanely 600cc-esque.

makes me

Whats your total top speed around then? surely it cant be like 80-85mph?

Originally Posted by flynjay

Yep. Plugged your info into the gearing commander website and you will be around 10K at 75mph.

I run 8.5K at 75 with 15/45 gearing.

ohh okay thanks for that i must have read it wrong. is it me or is that really bad top speed to loose possibly 20mph? sorry not good with the mechanical so i could just be going off on one

[flynjay]

Originally Posted by jack_bm

ohh okay thanks for that i must have read it wrong. is it me or is that really bad top speed to loose possibly 20mph? sorry not good with the mechanical so i could just be going off on one

If you weren't power limited then yes you would loose 20mph. But since the ninja doesn't have enough power to get to redline normally you are not loosing any on the top.

In actuality, you might have a slightly higher top speed than stock gearing. I find with 15/45 gearing I can go faster in 5th than I can in 6th.

[jack_bm]

Originally Posted by flynjay

If you weren't power limited then yes you would loose 20mph. But since the ninja doesn't have enough power to get to redline normally you are not loosing any on the top.

In actuality, you might have a slightly higher top speed than stock gearing. I find with 15/45 gearing I can go faster in 5th than I can in 6th.

riiight im getting this now lol, i think before i do this sprocket change i'll see what the top is, i've had 100mph out of her with everything stock but havnt tried to go above that because i know i'll end up getting bored if i know its limits, dont ask why its just how i am haha then i'll be able to compare thanks for all the help though good to know that i wont feel loosing the power to bad sorry for the thread jack as well

[choneofakind]

Originally Posted by jack_bm

Whats your total top speed around then? surely it cant be like 80-85mph?

Dunno. I don't really do top speed runs on roads. Fastest I got to was about 85 (corrected speed) on the freeway and was at about 11,000 rpm.

NOTE: I have 100/90-16 F, 130/90-16 rear tires. If you have 100/80-16 F and 130/80-16 rear, at 85 (corrected speed) you'll be turning 11,500 rpm with 14/47 gearing.

EDIT: ^ I was assuming you had a pregen... fyi, as long as you're on stock tires, you should be pulling about 11,500 rpm at 85. I was only talking about tire heights because my tires are not oem sizes, and are going to change my numbers a little bit.

[CZroe]

Originally Posted by jack_bm

riiight im getting this now lol, i think before i do this sprocket change i'll see what the top is, i've had 100mph out of her with everything stock but havnt tried to go above that because i know i'll end up getting bored if i know its limits, dont ask why its just how i am haha then i'll be able to compare thanks for all the help though good to know that i wont feel loosing the power to bad sorry for the thread jack as well

Just think of Newtonian physics with equal and opposite reactions for every action and you'll see why it can't go appreciably faster from a gearing change without some other factor like being redline-limited.

[diablos991]

I just swapped out my front sprocket and I noticed it has a bit of a clickity-clack when the rear tire i spinning either direction. The noise is something between the chain and the sprocket.

I also re-adjusted the chain (1 inch chain slack, rear wheel at same "tick mark"), wiped all the old grease off with a rag, and lubed it with some of this Dupont stuff: http://www.amazon.com/gp/product/B00...ls_o03_s00_i00

Anybody know how to fix this?

[trevor_shiggs]

Originally Posted by diablos991

I just swapped out my front sprocket and I noticed it has a bit of a clickity-clack when the rear tire i spinning either direction. The noise is something between the chain and the sprocket.

I also re-adjusted the chain (1 inch chain slack, rear wheel at same "tick mark"), wiped all the old grease off with a rag, and lubed it with some of this Dupont stuff: http://www.amazon.com/gp/product/B00...ls_o03_s00_i00

Anybody know how to fix this?

Does your noise sound like this? I got this noise when I did my sprocket swap. I don't remember it being there before.

http://www.youtube.com/watch?v=YYyax...ature=youtu.be

[diablos991]

Originally Posted by trevor_shiggs

Does your noise sound like this? I got this noise when I did my sprocket swap. I don't remember it being there before.

http://www.youtube.com/watch?v=YYyax...ature=youtu.be

This is exactly the sound! What is causing this?!
Maybe it is because we both have blue bikes.

[Fleshbazbo]

OEM countershaft sprockets have a large disc on each side of the sprocket. Sometimes the extra width of the sprocket also has a thin rubber cushion. This is designed to quiet the chain noise. Unfortunately, most aftermarket sprockets do not have this feature. Your new sprocket will work just fine but it will be, more noisy and may not last quite as long as the original. Hope this helps.

[lgk]

Originally Posted by diablos991

This is exactly the sound! What is causing this?!
Maybe it is because we both have blue bikes.

sounds like bad chain alignment.

[headshrink]

I think it's normal.

[PsHYk]

first...anyone got links to where i can get the sprockets?
and second...taking a chance at sounding like an idiot...does anything have to be done with the chain? or SHOULD there be something done with the chain...i read somewhere on another post something about a 415 chain? =/ so im just seeing what i need all together to make it the best output...

[thisisbenji]

I was thinking about doing the 15t front sprocket over the winter. My only worry is about riding on the track. I know that the 15t will lower my acceleration in 1st, but will it make much of a difference if I end up doing track days this summer?

[csmith12]

Originally Posted by thisisbenji

I was thinking about doing the 15t front sprocket over the winter. My only worry is about riding on the track. I know that the 15t will lower my acceleration in 1st, but will it make much of a difference if I end up doing track days this summer?

First off... Keep all your sprockets if they are in good condition, you just may need them later.

I ride track with a 15t sprocket. Depending on the track it may help or hurt. I mainly run my 250 at Putnam Park in IN and it lends itself very well to a 15t front because it keeps the bike in the power band longer and with less shifting between corners and such. Other tracks, maybe stock gearing would be better. For Mid-Ohio, I like stock gearing better because of the "drive corners" even though I am slower in the back straight.

If your NOT good at keeping the bike between 8k and 12k rpms, it can hurt you in the long run. It will help you if you are proficient at swapping them out. I don't always know what gearing to run on a new track or maybe I am feeling more/less aggressive that day.

Many factors go into keeping the bike really dialed into the powerband. Getting entry speeds right and being in the right gear at the right time just to name a few. It takes a while to build a relationship between the bike, track and rider. Once you have that, you can feel really good about selecting your gearing.

[thisisbenji]

Ah alright, I really want the 15t for highway usage, but was a little worried that it would hinder the bike. But it sounds like the key is to just keep it in the power band.

Also, about switching them. I was going to have someone do it for me, but maybe it's better to learn to do it myself huh?

[choneofakind]

Dude, it takes 10 minutes. Don't pay someone to do it for you.

Like Chris said, keep an extra sprockets so you have more options.

At Mid-Ohio, I was running 14/47 gearing; nice to rip out of corners, but I was having to shift like a mad man everywhere else and really make sure I was in the right gear on corner entry. I switched to 15/45 and really like it for commuting/general fun riding. I'll likely run the 15/45 next time (and keep it reving) I'm there, but take the 14/45 with me.

[Alex]

Why would you need to follow this DIY? When you take a peek at your sprocket and it looks like this:

bad sprocket.jpg

[radi4fun]

Is it just me or for those of you that changed the sprocket had a very tough time aligning the teeth of the sprocket with the spacer side facing in? I can't seem to get on properly. It's super easy put the sprocket into its place with the spacer facing out but when I turn it sound and have the letters facing inwards, It's nearly impossible. Don't know what I'm doing.

[NewbieNinja]

Originally Posted by radi4fun

Is it just me or for those of you that changed the sprocket had a very tough time aligning the teeth of the sprocket with the spacer side facing in? I can't seem to get on properly. It's super easy put the sprocket into its place with the spacer facing out but when I turn it sound and have the letters facing inwards, It's nearly impossible. Don't know what I'm doing.

I don't think you know what you're doing. I just did this on Monday and it went in fairly easy. I do have the JT 15T though. Maybe you have a vortex or something else?

[radi4fun]

I figured it out, i had to line up the teeth perfectly before sliding it and i had to slide it in perfectly straight, if it was a little bit turned/angled, it wouldn't go in. just changing the front to 15T doesn't really make too much of a difference. I'll have to also change the rear at some point. there is a little drop in RPM but i wished there was more.

[LNasty]

So do you have to change out the chain and the rear sprocket if you are changing out the front sprocket? I have read the the wear characteristics on the chain and rear sprocket will be compromised if you put on a brand new 15t front sprocket. Anyone know if you have to switch it all out if you install a new one?

F.Y.I I have 4500 miles on the factory chain and sprockets

[headshrink]

Originally Posted by LNasty

So do you have to change out the chain and the rear sprocket if you are changing out the front sprocket? I have read the the wear characteristics on the chain and rear sprocket will be compromised if you put on a brand new 15t front sprocket. Anyone know if you have to switch it all out if you install a new one?

F.Y.I I have 4500 miles on the factory chain and sprockets

If you don't see noticeable wear, don't worry about it. You'll still get lots of life out of it, and can always switch it all out next time.

[broken neck]

Ok, so today I tried to change my sprockets and chain.

I haven't been able to remove the front sprocket cover. I removed the three bolts and the shifter linkage. I could move the upper port of the cover, but the lower part seemed stock there. Is there some kind of "hidden stud" next to the lower bolt (on its right)? I tried applying force with a bar but nothing wanted to move.

Anyone had this problem?

Thanks

[headshrink]

Originally Posted by broken neck

Ok, so today I tried to change my sprockets and chain.

I haven't been able to remove the front sprocket cover. I removed the three bolts and the shifter linkage. I could move the upper port of the cover, but the lower part seemed stock there. Is there some kind of "hidden stud" next to the lower bolt (on its right)? I tried applying force with a bar but nothing wanted to move.

Anyone had this problem?

Thanks

My guess is one of the metal alignment dowels are just a little stuck.

[broken neck]

Thanks headshrink,

I'll ask my friend to put some liquidwrench in that area, to let it work until next time... Hope it will loosen that alignment pin...

[headshrink]

Originally Posted by broken neck

Thanks headshrink,

I'll ask my friend to put some liquidwrench in that area, to let it work until next time... Hope it will loosen that alignment pin...

No problem. It may be difficult to get liquid wrench in the right spots, but you might want to try tapping the sides of the cover to see if that breaks it loose. You can also VERY CAREFULLY see if you can twist a screwdriver under the cover to pry it up a smidge. You just want to break the grime. Be super careful though, because you don't want to bend those dowels. Also, if you haven't already, when you eventually get it off you'll see why most of us switch to chain wax.

[Amsler457]

Looking for faster acceleration. Would a 13 t front be a noticeable difference? And do I need to shorten chain? Also does anyone have any links to a 13t front sprocket that is good I can purchase for my bike? And I am looking into a k&n filter to let her breathe better? Any opinions ?

[headshrink]

More torque, yes. But IMO you would move through the first couple gears so fast that you may not feel like it. Shift, shift, shift slows you down a bit too. 15T is my preference because it smooths everything out and puts the shifting points where I intuitively feel they "should" be. It's personal opinion though, and for about $25 you can try a new counter-sprocket and not be out a lot of money if you don't like it.

I read on another board that 1T on the counter-sprocket is aprox. equal to 3T on the rear (not sure, just repeating). Assuming this is true, you could theoretically "fine tune" your gearing by making adjustments in the back too.