I put new sprockets on my bike today.

Put 43-15. the bike only has 300 miles so i left the old chain on there.

This gave me 1000 rpm lower in top gear@ whatever speed. Its like having another gear, and it only took an hour:thumbup:

I put a 15T on the front and have enjoyed the "extra" gear ever since. Very good mod.

This gave me 1000 rpm lower in top gear@ whatever speed. Its like having another gear, and it only took an hour:thumbup:

Well, not exactly. The new sprockets made your gearing 12.1% taller no matter what speed you're going. (15/14 * 45/43). But 1000 rpm difference is in the ball park for highway speeds; if you were turning around 8500 rpm before, it would be very close to 7500 rpm after the swap. (But if you were at half the speed, and only turning 4250 in top gear, it would only drop 500 rpm after the swap). Conversely, if you were up near redline before, the gearing switch would change 13k down to 11.6k or so, well over a 1000 RPM difference.

REDLINE? omg I only have 300 miles on it. :):)

The tach is hard to read at night, could be off a little. :)

REDLINE? omg I only have 300 miles on it. :):)

The tach is hard to read at night, could be off a little. :)


I was slapping redline all day long in the mountains one saturday. The day started with about 50 miles on the odo and ended with about 350. Don't be afraid... go ahead and goose that girl :thumbup:

i have the 15 and would like to go down in the back too..but it's so hilly around here i'm not sure yet.

How is the power? i like how zippy it is right now, but would like a little better milage. I mostly ride mine to work, which is mostly highway.

How is the power? i like how zippy it is right now, but would like a little better milage. I mostly ride mine to work, which is mostly highway.

The power is not adversly affected. I still have plenty of passing power.

I have similar results. With a 15/44 setup, my RPMs at a true 80mph dropped from about 10,200 to 9,100. Also, first gear is a bit more usable.

does changing sprockets give you inaccurate miles on the odometer ? I've seen a few CL ads that say this.

On most bikes yes, on the ninjette no. Our speedometer/odometer is driven off a sprocket on the front tire. Changing gearing from the motor to the driven wheel has no effect on how often the front tire turns compared to the engine.

Most modern motorcycles instead get the speedo/odo drive off of the transmission output, and in that case gearing changes do directly affect the accuracy of the gauges.

On most bikes yes, on the ninjette no. Our speedometer/odometer is driven off a sprocket on the front tire. Changing gearing from the motor to the driven wheel has no effect on how often the front tire turns compared to the engine.

Most modern motorcycles instead get the speedo/odo drive off of the transmission output, and in that case gearing changes do directly affect the accuracy of the gauges.

I see, thanks :thumbup:

I changed sprockets to get lower engine speed, better mileage, and maybe longer engine life. If I get a little less power, it's not a problem.

I live in s.w. florida, so no fun hills or even roads with curves in them.:(

Hills are not a problem for me. All you have to do is downshift and you have plenty of pulling power.

I put on a 16T front just after I bought the bike. It made for much lower RPM at highway speeds. After swapping out to the stock tires with GT-501's, I put the 14T back on. The combination of the taller tires and larger sprocket, wasn't great. I had to feather the clutch way to much on take off.

I plan on swapping a 15T on mine in the spring. (keeping the 45 out back)

I plan on swapping a 15T on mine in the spring. (keeping the 45 out back)

That's what I did earlier this year and love it. I commuted a lot with my bike so going at a lower RPM at the same speed made my commute much more comfortable. With people going 70mph in the mornings, it sucked not wanting to keep up.

It still accelerates fine, but initially in first gear, the bike feels a tad slower. So...I just rev a bit more! :)

I know that this is a subjective question, but how much slower does it feel with the 15/45 setup? Is it noticeable? Did you have to raise your launch slip rpm? Do you find that it needs noticeably more throttle to get moving?

Thanks,
Adam

It's noticeable, but it's really not bad unless you're accelerating from a stop. Once you get going, it feels just the same. Once you get used to how it feels, you will probably barely remember how it used to feel with a 14T sprocket up front!

I was slapping redline all day long in the mountains one saturday. The day started with about 50 miles on the odo and ended with about 350. Don't be afraid... go ahead and goose that girl :thumbup:

Even the "hard" break-in methods don't suggest doing that without a few oil changes thrown in there!

Even the "hard" break-in methods don't suggest doing that without a few oil changes thrown in there!


Did you read what I quoted in that post? It was about him worrying about redlining with only 300 miles on the bike, nothing about oil changes. If it bothers you wondering, I drained and refilled the oil before that ride (no new filter).

I read this add to see if i could solve a problem im having. I swapped the sprocket to 15t in the front and I was riding this weekend behind my buddy in his car and i told him to do the speed limit bc i thought my speedometer was off and it wasnt the weekend to be speeding so i followed him and it said i was doing 80 to keep up with hime but when we got to the house he said he put it on cruise at 65 and nothing more so why would i be off by like 15 mph???