Moving from 15t to a 16t sprocket - Kawasaki KLR 650 Forum
KLR & Other Motorcycle Related Discussion Grab a seat and discuss whatever you like about the KLR or other related topics. Within reason.

 3Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 26 Old 05-22-2017, 01:38 PM Thread Starter
1st Gear
 
Join Date: Aug 2016
Location: Earth, Terran System
Posts: 24
Moving from 15t to a 16t sprocket

Only about 1000 miles on the chain/sprockets, but taking a mostly-highway trip and want the 16t.

Can I safely swap in the 16t sprocket without replacing the chain?

Thanks!
slackard is offline  
Sponsored Links
Advertisement
 
post #2 of 26 Old 05-22-2017, 04:57 PM
5th Gear
 
Join Date: Jan 2011
Posts: 4,148
Yes; however . . . adjust for proper chain slack when you install the larger sprocket.

You will then spin the engine only 15/16 (0.9375) the rpm at your previous speed . . . or you will go 16/15 (1.066) as fast at the previous rpm . . .

Example: Stock, you turn 4,000 rpm at a given speed. With your 16-tooth countersprocket, you will turn only 3750 rpm at the same speed. A savings of 250 rpm at that speed.

5000 rpm stock? Only 4688 rpm, less 312 rpm at the same speed with the 16-tooth countershaft sprocket.

Worth buying the extra sprocket, getting your hands greasy while installing it and adjusting the chain?

You decide!

Last edited by Damocles; 05-22-2017 at 07:36 PM.
Damocles is offline  
post #3 of 26 Old 05-22-2017, 05:37 PM Thread Starter
1st Gear
 
Join Date: Aug 2016
Location: Earth, Terran System
Posts: 24
The 16t is in the mail already.

When i bought the bike it had the 16t on it.. I then replaced both sprockets & the chain, going with 15/43, which is great for around town.

Now though, I want to take this longer highway trip and lower RPM for a given speed is my goal.

Good to know I wont need a new/longer chain.

Thanks!
slackard is offline  
 
post #4 of 26 Old 05-22-2017, 07:37 PM
5th Gear
 
Join Date: Jan 2011
Posts: 4,148
Again, just be sure to adjust chain tension adequately--better too loose, than too tight!
Damocles is offline  
post #5 of 26 Old 05-23-2017, 11:54 AM
Neutral
 
Join Date: May 2017
Posts: 4
Greetings all,

Kindly confirm the optimal sprocket replacement options to improve performance on the KLR650?

Many thanks,
Tom
Tom6710 is offline  
post #6 of 26 Old 05-23-2017, 05:12 PM
5th Gear
 
Join Date: Jan 2011
Posts: 4,148
Quote:
Originally Posted by Tom6710 View Post
Greetings all,

Kindly confirm the optimal sprocket replacement options to improve performance on the KLR650?

Many thanks,
Tom
"Optimum" in this context appears subjective, to me: Depends upon your riding style and environment.

And . . . a gear change won't "improve" performance, per se. Rather . . . changing the ratio changes the torque multiplication of the drive train, not unlike shifting gears. For example, changing from second to third gear does not "improve" performance, but . . . second gear multiplies torque at a greater ratio than third (and higher) gears.

Heavily-laden bike, ridden slowly over rugged off-road terrain, maybe you want more drivetrain torque multiplication: Dropping down a countershaft sprocket tooth, or adding a few rear sprocket teeth might be more, "optimum" for that situation.

Whizzing down the Interstate unladen: Maybe you want greater speed vs. engine rpm; you may want more countershaft sprocket teeth, and/or fewer rear sprocket teeth.

The AMOUNT of torque multiplication is a direct and simple mathematical comparison: For example, changing from the stock 15-tooth countershaft sprocket to a 16-tooth countershaft sprocket reduces torque multiplication by the factor of 15/16. Going from 15 teeth to 14 teeth, torque is multiplied by a factor of 15/14.

Please keep in mind: The absolute torque produced by the engine remains unchanged; changing sprocket teeth number affects the multiplication of that torque where the rubber meets the road.
Damocles is offline  
post #7 of 26 Old 05-24-2017, 08:20 PM
Neutral
 
Join Date: May 2017
Posts: 3
Seems ok to me. 1000 miles isn't much wear. I just changed mine. 2017 klr650. only had 200 miles on it but could already tell I needed to change the sprocket setup. I went with a 16 but also changed the rear to a 42. It bogs off the line but is way way better at high speeds. Still breaking it in so can't go over 4k. its at about 3800 rpms at 60mph. I may go back to the 43 rear because I'm worried about burning the clutch up due to the slow starts.
ScottyKLR is offline  
post #8 of 26 Old 05-26-2017, 01:23 AM
Neutral
 
Join Date: May 2017
Posts: 4
Thanks for the Gen.. I basically want a little more speed for a given RPM on the freeway. Which sprocket is which? The rear versus the smaller front one and what sizes do I order?
Tom6710 is offline  
post #9 of 26 Old 05-28-2017, 08:29 AM
3rd Gear
 
shinyribs's Avatar
 
Join Date: Aug 2016
Posts: 527
Quote:
Originally Posted by Tom6710 View Post
Thanks for the Gen.. I basically want a little more speed for a given RPM on the freeway. Which sprocket is which? The rear versus the smaller front one and what sizes do I order?

To lower rpm at a given speed you will need to either have to increase the number of teeth on the front sprocket, or lower the number of teeth on the rear sprocket.

16 teeth up front is basically the maximum amount that will fit in the area. Though I've heard of squeezing in a 17T, but I think it required grinding away some material somewhere.

1 tooth on a front sprocket roughly equals 3 teeth on a rear sprocket. Most people choose to swap front sprockets since they cost less and you dont have to buy a new, shorter chain ( or cut yours down) like running a smaller rear sprocket requires.
shinyribs is offline  
post #10 of 26 Old 05-28-2017, 11:25 AM
Neutral
 
Join Date: May 2017
Posts: 4
Talking

Super! Many thanks..
Tom6710 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki KLR 650 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
2009 klr 650. 16t sprocket and chain sizing tylerw 2008+ KLR650 Wrenching & Mod Questions 21 10-07-2011 03:06 PM
16t front sprocket for '08. hography 2008+ KLR650 Wrenching & Mod Questions 6 08-09-2011 10:18 PM
Back to 15T indyjay 1987 to 2007 Wrenching & Mods 5 08-19-2009 11:17 AM
16t sprocket for klr jr (250) jtaylor 1987 to 2007 Wrenching & Mods 6 01-21-2009 12:32 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome