Welcome back to us :/ Our hosts data center was down for the entire day.
MotoHouston.com MotoHouston.com
Register Members List Member Map Media Calendar Garage Forum Home Mark Forums Read

Go Back   MotoHouston.com > General Discussion > General Discussion (Moto Related)
Forgot info?

Welcome to MotoHouston.com! You are currently viewing our forums as a guest which gives you limited access to the community. By joining our free community you will have access to great discounts from our sponsors, the ability to post topics, communicate privately with other members, respond to polls, upload content, free email, classifieds, and access many other special features. Registration is fast, simple and absolutely free, join our community!

Register Today!

If you have any problems with the registration process or your account login, please contact us.


Like us on Facebook! Regular shirt GIVEAWAYS and more

Advertisement

Reply
Share This Thread: 
Subscribe to this Thread Thread Tools
Old 02-01-2016, 02:27 PM   #1
JaceMass
Member
 
Join Date: Jan 2016
Location: Bluegrove, TX
Feedback Rating: (0)
Posts: 33

Experience: 1-3 months

Bike(s):
1987 Honda Rebel CMX250









Changing Sprocket Sizes and Tires

So I'm on an old 1987 Honda Rebel and wanted to go up one tooth on the font and down two on the rear. I'm replacing the tires soon so I figured I'd ask the shop to replace the old sprockets and chain for me when they swapped the tires. My question is, how do you think going from a 14 to a 15 and a 33 to a 31 would effect my 250cc bike at hwy speeds.
JaceMass is offline   Reply With Quote
Similar Topics
Thread Thread Starter Forum Replies Last Post
50 tires sizes GCgixxer685 Dirtbikes, Mini's, ATV's..... 2 03-27-2013 12:50 PM
Changing stock sprocket 06 GSX-R 600 DR91LX How To's and Q & A's 1 07-08-2011 02:24 AM
changing front sprocket on 06 gsxr 600 ?? patgsxr How To's and Q & A's 1 07-29-2010 11:10 AM
sprocket sizes ? lanzer913 General Discussion (Moto Related) 32 05-01-2009 11:33 AM
Changing front sprocket THE DEAN OF LEAN How To's and Q & A's 17 03-25-2009 11:10 PM
Advertisement
Old 02-01-2016, 04:24 PM   #2
Shuhboogie
IS AFK
 
Join Date: Aug 2015
Location: Cypress area
Feedback Rating: (0)
Posts: 564

Experience: 10+ years











I'm on a CBR250 and did the 1up, 2down sprocket swap. I went to a 15 front and from 38 to 36 rear. Here are the differences I found:
Your shift points are longer.
The bike dropped a thousand rpm's at highway speeds. I used to run 7500 rpm's in 6th gear at 70mph. Now I run 6500rpm's.
The bike feels better and vibrates less but 6th gear is like a serious overdrive. Its great for flat roads but dont expect any acceleration.
I also lost some top end speed. You can ask anyone I have ridden with, I spend my time waiting for intersections so I can catch up to the group.
I will say, with all that, I am extremely pleased with having done the swap.
Good luck
Shuhboogie is offline   Reply With Quote
Old 02-01-2016, 05:06 PM   #3
JaceMass
Member
 
Join Date: Jan 2016
Location: Bluegrove, TX
Feedback Rating: (0)
Posts: 33

Experience: 1-3 months

Bike(s):
1987 Honda Rebel CMX250









Quote:
Originally Posted by Shuhboogie View Post
I'm on a CBR250 and did the 1up, 2down sprocket swap. I went to a 15 front and from 38 to 36 rear. Here are the differences I found:
Your shift points are longer.
The bike dropped a thousand rpm's at highway speeds. I used to run 7500 rpm's in 6th gear at 70mph. Now I run 6500rpm's.
The bike feels better and vibrates less but 6th gear is like a serious overdrive. Its great for flat roads but dont expect any acceleration.
I also lost some top end speed. You can ask anyone I have ridden with, I spend my time waiting for intersections so I can catch up to the group.
I will say, with all that, I am extremely pleased with having done the swap.
Good luck
Well the suggestion was made for a trip I'm planning. Speed isn't a big deal since I ride alone anyway. I should be able to ride at 70 or so no problem afterwards, right?
JaceMass is offline   Reply With Quote
Old 02-01-2016, 05:23 PM   #4
Shuhboogie
IS AFK
 
Join Date: Aug 2015
Location: Cypress area
Feedback Rating: (0)
Posts: 564

Experience: 10+ years











Quote:
Originally Posted by JaceMass View Post
Well the suggestion was made for a trip I'm planning. Speed isn't a big deal since I ride alone anyway. I should be able to ride at 70 or so no problem afterwards, right?
Oh yeah. 70 is not a problem. If you find yourself facing a strong head wind you may have to run in the next lower gear. Which is no big deal since its like running in high gear before the sprocket swap.
I think you will be most happy with the time between shift points when you take off. It made such a big difference on my bike. Made it more enjoyable to ride.
Shuhboogie is offline   Reply With Quote
Old 02-01-2016, 05:33 PM   #5
EnduroJoe
Senior Member
 
EnduroJoe's Avatar
 
Join Date: Jul 2013
Feedback Rating: (0)
Posts: 207


Bike(s):
02' KTM LC4 Enduro









http://www.gearingcommander.com
EnduroJoe is offline   Reply With Quote
Liked this post:
Old 02-01-2016, 06:56 PM   #6
JaceMass
Member
 
Join Date: Jan 2016
Location: Bluegrove, TX
Feedback Rating: (0)
Posts: 33

Experience: 1-3 months

Bike(s):
1987 Honda Rebel CMX250









Quote:
Originally Posted by Shuhboogie View Post
Oh yeah. 70 is not a problem. If you find yourself facing a strong head wind you may have to run in the next lower gear. Which is no big deal since its like running in high gear before the sprocket swap.
I think you will be most happy with the time between shift points when you take off. It made such a big difference on my bike. Made it more enjoyable to ride.
Did you chain accommodate the alteration, or did you buy a new one?
JaceMass is offline   Reply With Quote
Old 02-01-2016, 11:28 PM   #7
Shuhboogie
IS AFK
 
Join Date: Aug 2015
Location: Cypress area
Feedback Rating: (0)
Posts: 564

Experience: 10+ years











Quote:
Originally Posted by JaceMass View Post
Did you chain accommodate the alteration, or did you buy a new one?
Apologize for the late reply. Life got busy this afternoon.
I did buy a new chain but that was before I decided to do the sprocket swap.
You will probably need to have a link or so removed. I didn't remove any so mine is adjusted about as far back as you can go. I haven't had any issues so far and have put about 8,000 miles on it since the swap.
Shuhboogie is offline   Reply With Quote
Old 02-01-2016, 11:31 PM   #8
Shuhboogie
IS AFK
 
Join Date: Aug 2015
Location: Cypress area
Feedback Rating: (0)
Posts: 564

Experience: 10+ years











Don't forget, when you do the swap your speedo is going to be wrong. I bought a speedo healer to fix mine. Now mine is .4mph off of actual. Not too shabby.
Shuhboogie is offline   Reply With Quote
Old 02-02-2016, 09:37 AM   #9
Flynjay
Senior Member
 
Flynjay's Avatar
 
Join Date: Nov 2011
Location: League City
Feedback Rating: (0)
Posts: 358

Experience: 5 years

Bike(s):
'07 Ninja 250 (sold)
'06 Ninja 650








Quote:
Originally Posted by Shuhboogie View Post
Don't forget, when you do the swap your speedo is going to be wrong. I bought a speedo healer to fix mine. Now mine is .4mph off of actual. Not too shabby.
Since the speedometer cable is attached to the front wheel, how does changing the gearing effect the speedo?
Flynjay is offline   Reply With Quote
Old 02-02-2016, 09:46 AM   #10
pinball
I got slow
 
pinball's Avatar
 
Join Date: Feb 2011
Location: SE
Feedback Rating: (0)
Posts: 4,683

Experience: 4 years
Trackdays: 2


Big dirt bike (sold)
2003 Honda Sabre (sold)







Quote:
Originally Posted by Shuhboogie View Post
Oh yeah. 70 is not a problem. If you find yourself facing a strong head wind you may have to run in the next lower gear. Which is no big deal since its like running in high gear before the sprocket swap.
I think you will be most happy with the time between shift points when you take off. It made such a big difference on my bike. Made it more enjoyable to ride.
You realize his bike has half the HP and one less gear than yours, right?
__________________
Quote:
Originally Posted by bun1t View Post
Shelnutt thinks mechanics should work for free
pinball is offline   Reply With Quote
Old 02-02-2016, 09:47 AM   #11
Jae
Kilted Basterd
 
Jae's Avatar
 
Join Date: Sep 2007
Location: Richmond
Feedback Rating: (9)
Posts: 5,076

Experience: 9 years

Bike(s):
Naked Sprint
Russian POS
Angry Max/Tub
Pile o' Hyosungs

Member Garage


keep in mind a newer CBR250 is not an apples-to-apples comparison with an '87 CMX250...

your best bet for finding advice on rebel modifications will be to find a forum for rebels and read around there.
http://www.hondarebelforum.com/

http://www.hondarebelforum.com/f77/n...ket-584-2.html
http://www.hondarebelforum.com/f28/c...eter-4186.html
http://www.hondarebelforum.com/f12/s...ing-77153.html
http://www.hondarebelforum.com/f77/1...-11393-13.html
__________________
Keeping the "F-U" in "fun"

Last edited by Jae; 02-02-2016 at 09:50 AM.
Jae is offline   Reply With Quote
Liked this post:
Old 02-02-2016, 02:08 PM   #12
Shuhboogie
IS AFK
 
Join Date: Aug 2015
Location: Cypress area
Feedback Rating: (0)
Posts: 564

Experience: 10+ years











Ok. Ball busters. Lol
16hp compared to 24 isn't half. The size of the rider makes a bit of a difference too.
If there is concern then I would do the swap on the front first. See and how ya like it. See how well it pulls ya down the road and then decide if ya want to try the back. Swap the easier of the two first. If the speedo connects to the front wheel then fine. Your done. I expect this person is smart enough to know that since it is their bike and disregard that statement.
Ok. I'm done for now. Love ya.
Shuhboogie is offline   Reply With Quote
Old 02-02-2016, 04:05 PM   #13
Jae
Kilted Basterd
 
Jae's Avatar
 
Join Date: Sep 2007
Location: Richmond
Feedback Rating: (9)
Posts: 5,076

Experience: 9 years

Bike(s):
Naked Sprint
Russian POS
Angry Max/Tub
Pile o' Hyosungs

Member Garage


Quote:
Originally Posted by Shuhboogie View Post
Ok. Ball busters. Lol
16hp compared to 24 isn't half. The size of the rider makes a bit of a difference too.
If there is concern then I would do the swap on the front first. See and how ya like it. See how well it pulls ya down the road and then decide if ya want to try the back. Swap the easier of the two first. If the speedo connects to the front wheel then fine. Your done. I expect this person is smart enough to know that since it is their bike and disregard that statement.
Ok. I'm done for now. Love ya.
Comments weren't directed at you, as much as the OP. This appears to be a new-to-him bike that he picked up not running for a few hundred dollars, assuming I'm putting together all the info from the 5 or 6 separate threads properly.
__________________
Keeping the "F-U" in "fun"
Jae is offline   Reply With Quote
Old 02-02-2016, 04:56 PM   #14
bluewave18
Safety Third
 
bluewave18's Avatar
 
Join Date: Oct 2007
Location: S.E.
Feedback Rating: (0)
Posts: 34,121

Experience: 10+ years

Bike(s):
08 Busa
03 XR 50








that does seem like a lot of gear for a bike with no power at all
__________________
"Just curious,wife turns 40 soon. And I have a bucket list to accomplish. She can get frisky after a few drinks which I haven't used to my full advantage, YET!"
bluewave18 is offline   Reply With Quote
Old 02-02-2016, 08:17 PM   #15
Shuhboogie
IS AFK
 
Join Date: Aug 2015
Location: Cypress area
Feedback Rating: (0)
Posts: 564

Experience: 10+ years











Quote:
Originally Posted by bluewave18 View Post
that does seem like a lot of gear for a bike with no power at all
It may be. Swapping the front to a 15 may be all he needs. Or all the bike can handle. , if that 33 rear would fit my 250 that would be awesome. I'd go to a 13 front. Lol
Shuhboogie is offline   Reply With Quote
Old 02-02-2016, 11:44 PM   #16
Volfy
Fava Beans & a Chianti
 
Volfy's Avatar
 
Join Date: Dec 2011
Location: SW Houston
Feedback Rating: (0)
Posts: 3,504

Experience: 10+ years
Trackdays: 1

Bike(s):
'15 300RR
'15 250XCF-W
'14 Trophy SE
'10 VFR1200F
'05 GSXR600 (track)

Member Garage





Get that bike running FIRST, then ride it around to see how you like the stock gearing. Any suggestion right now is pure conjecture on a 30yr old bike nobody knows what shape it's in.

Hats off the OP for dreaming big, but I highly recommend forgetting about the trip for now. Get that bike fixed up is gonna be an adventure all by itself.
Volfy is offline   Reply With Quote
Old 02-03-2016, 06:16 PM   #17
JaceMass
Member
 
Join Date: Jan 2016
Location: Bluegrove, TX
Feedback Rating: (0)
Posts: 33

Experience: 1-3 months

Bike(s):
1987 Honda Rebel CMX250









bike

Quote:
Originally Posted by Volfy View Post
Get that bike running FIRST, then ride it around to see how you like the stock gearing. Any suggestion right now is pure conjecture on a 30yr old bike nobody knows what shape it's in.

Hats off the OP for dreaming big, but I highly recommend forgetting about the trip for now. Get that bike fixed up is gonna be an adventure all by itself.
Got it running today. Need a battery and ignition.
JaceMass is offline   Reply With Quote
Old 02-03-2016, 06:19 PM   #18
JaceMass
Member
 
Join Date: Jan 2016
Location: Bluegrove, TX
Feedback Rating: (0)
Posts: 33

Experience: 1-3 months

Bike(s):
1987 Honda Rebel CMX250









Doing a rebuild on the carburetor, changing tires, and engine rebuild after I move. It's sounds okay but just to be safe. It ran when I bought it, but the key broke off when we turned off the ignition.
JaceMass is offline   Reply With Quote
Old 02-05-2016, 08:38 AM   #19
Shuhboogie
IS AFK
 
Join Date: Aug 2015
Location: Cypress area
Feedback Rating: (0)
Posts: 564

Experience: 10+ years











Quote:
Originally Posted by JaceMass View Post
Doing a rebuild on the carburetor, changing tires, and engine rebuild after I move. It's sounds okay but just to be safe. It ran when I bought it, but the key broke off when we turned off the ignition.
Sucks the key broke. You will find a lot of little things like that. Don't let it frustrate ya. I'm working on putting a 73 CB350FOUR back on the road. I have literally hunted the globe for parts. Only to find the old parts don't want to come off to be replaced. I have thrown a couple wrenches and kicked a few things but I haven't given up, yet. LOL
Shuhboogie is offline   Reply With Quote
Reply


Thread Tools

Advertisement


All times are GMT -5. The time now is 07:53 AM.


MotoHouston.com is not responsible for the content posted by users.
Privacy Policy