[ydo]

Just last weekend I was on a long group ride (about 350 miles) when just 8 miles from home suddenly my bike started to wobble. I was going 65 mph so I slowed quickly to a stop and sure enough I had a complete flat in the rear tire. Long story short I put a plug and had to add some fix a flat to get me home.

I took the wheel off and saw it was easy to take the rear sprocket off. I did some research and decided to change it from a 41 tooth to a 39 tooth sprocket. I bought a new tire (Michelin Pilot Road 4 which could be a new thread) and just got it together. I took a short ride slowly to wear the new tire in so I can't be sure of the results yet.

My goal was to lower my rpms a little, especially at highway speeds. I estimate to lower 200 rpm at 60 mph. Has anyone done this change and what are the results?

 

[Northern Ninja]

I went +1,-2, and it dropped the rpms by about 700 at 70mph. I also went to a 190/55 rear which almost healed my speedo!

 

[ydo]

How do you like the loss of torque? I read in another forum that some miss the loss of pop in the lower gears. With the limited testing (and today rain) I didn't feel the loss was that huge. You, on the other hand, went with an extra tooth on the front sprocket to double the effect so you really changed the bike characteristics.

 

[Northern Ninja]

The bike was geared pretty low to begin with, so I didn't really notice the difference. I'm used to a ZX10 though, which is geared stupid high so... I love it on the highway now. Huge difference there.

 

[Norskie]

I still have the FJR1300 and while it has more hp/torque than the Ninja, top gear (5th) has it running at a significantly lower RPM than the Ninja. This results in a more relaxed, less buzzy cruise, at the cost of roll-on acceleration. There's plenty of torque in 5th to pass cars, and if more is needed then 4th (and even 3rd) gear is just a click or two away.

When changing the gearing on the Ninja to reduce cruising RPM I would certainly expect less torque at any given RPM but just like the FJR< that can be quickly remedied by selecting a lower gear.

As it is, the Ninja's 3,4,5 gears are too close together to be usefull on the street and 6th should be longer.

Ideally, I'd have a good excuse to crack the engine open and adjust some of the gear ratios to spread them out some.

 

[Mikey1000]

I went +1,-2, and it dropped the rpms by about 700 at 70mph. I also went to a 190/55 rear which almost healed my speedo!

Working on that same plan myself, gathering the parts for winter(?) install as the N1K is in Florida & I'm in NY.

 

[Ferdinand]

I went +1,-2, and it dropped the rpms by about 700 at 70mph. I also went to a 190/55 rear which almost healed my speedo!

I just went with the JT +1 front and am looking to do the -2 rear. Did you got JT on each?

 

[Pete]

I bought the JT 16. When I put in on, it sticks out about 1/8" further than the stock sprocket. I didn't like the way it lined up with the rear, so returned it for a stock 15 tooth (on order). Decided to change the rear with a JT 39.

 

[StumpyNB]

I just did the swap to 16/39 and so far I really like it. Only one relatively quick ride so far, but it was 2 up for about a half hour. Definitely clutching a but more pulling away from a stop, but I love not having to shift as much. You can't whack it wide open in first on this bike anyway.

 

[Mikey1000]

I went with 39 tooth rear from Supersprox. Anodized gold center(aluminum) with black steel teeth.

 

[Ferdinand]

I bought the JT 16. When I put in on, it sticks out about 1/8" further than the stock sprocket. I didn't like the way it lined up with the rear, so returned it for a stock 15 tooth (on order). Decided to change the rear with a JT 39.

After I did the JT 16 I didn't notice the 1/8" difference, but did notice a slight vibration when rolling to a stop. I feel it in the brake pedal. Very slight.

I just switched to a JT 39 rear and it's actually less noticeable. A brand thing? Who knows...? But..

I really like the combo. This bike is primarily a touring bike for me so quarter mile times are not important. 500 mile days at 80mph are. The big windshield (V-Stream) and taller gears gives it nice legs and hopefully better mpg. I'd recommend the gearing change for anyone looking to tour more. It demonstrates the great versatility Kaw built into this bike.

 

[Ferdinand]

Bug Collection

Yep.
Works great for touring. Nearly 2k since the front sprocket upgrade and 1k (ish) on the rear...
This set up really has legs. Great if you're into bug collections.

 

[Pete]

It was pretty noticeable, it just didn't look right. Maybe I got a bad one? Anyway, I did a short ride with stock front and JT 39 rear and it is like a new bike.
As a side story, I just put on V and H Urban Brawlers. They are worth every penny.

After I did the JT 16 I didn't notice the 1/8" difference, but did notice a slight vibration when rolling to a stop. I feel it in the brake pedal. Very slight.

I just switched to a JT 39 rear and it's actually less noticeable. A brand thing? Who knows...? But..

I really like the combo. This bike is primarily a touring bike for me so quarter mile times are not important. 500 mile days at 80mph are. The big windshield (V-Stream) and taller gears gives it nice legs and hopefully better mpg. I'd recommend the gearing change for anyone looking to tour more. It demonstrates the great versatility Kaw built into this bike.

 

[Airman]

I went with 39 tooth rear from Supersprox. Anodized gold center(aluminum) with black steel teeth.

Did you still use the stock chain length?

 

[Ferdinand]

Important Side Note

Yep.
Works great for touring. Nearly 2k since the front sprocket upgrade and 1k (ish) on the rear...
This set up really has legs. Great if you're into bug collections.

A few thousand miles later on all roads and conditions and I think it's important to note:

If you do this mod, you will have less engine braking. If you have non ABS just know that braking can get adventurous below 40 mph. Hard stops from highway speeds are still okay down to around 40, but below that it's all binders and sliding is a real possibility.

 

[ToNY97]

So just to recap: Changing to a 16T up front will give me the lower rpms at highway speeds
WITHOUT having to change the rear sprocket?

 

[StumpyNB]

I originally went to 16/39. But ended up changing the rear back a few weeks later. Didn't like the loss of power. 16 up front instead of 15 is perfect. One or the other though, not both.

 

[sdkoskey]

I originally went to 16/39. But ended up changing the rear back a few weeks later. Didn't like the loss of power. 16 up front instead of 15 is perfect. One or the other though, not both.

I'm going to 16/40 tomorrow. I'm hoping this'll be a really nice happy medium.

So just to recap: Changing to a 16T up front will give me the lower rpms at highway speeds
WITHOUT having to change the rear sprocket?

Correct.

 

[alang]

have 16 41 now; ordered 40 rear.

 

[ToNY97]

Thank you