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Discussion Starter #1 (Edited)
My Rear sprocket is 43T on my 09 scrambler
I'm a newbie to scramby.
I'm planning to change my front sprocket teeth but absolutely have no clue to how will it affect my riding style or how it will affect to my engine on long run

Few Questions?

1.Does the front sprocket have 18T?
2.Say if the stock Front has 18T what happens if I go down a teeth or two?
What happens if I go up a teeth or two?

By going down a teeth or two how does it affect the riding style & engine
By going up a teeth or two how does it affect the riding style & engine

I'm not a racer by any means but I want to have less vibrations in my engine when I'm doing higher speeds on freeway around 85-95mph

Pls help
 

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Your front sprocket should be an 18T

If you go down in size to a 16 or 17, you will be lowering the top speed, increasing the revs at any given speed throughout the range, and the bike will accelerate faster.

If you go up to a 19, your top speed would theoretically increase, your revs will drop a bit throughout the range, and it will accelerate slightly slower.

Having said all that, if you want a 19T sprocket, I have one that I will sell for cheap.
 

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Discussion Starter #3
sorry another question
if I change the teeth in front sprocket do I need to change the teeth in my rear also?
 

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sorry another question
if I change the teeth in front sprocket do I need to change the teeth in my rear also?
NO
you can change just the front sprocket.
it is easy and inexpensive.
If your going trail/dirt riding
I would recommend drop a tooth
(one less tooth is a 17 from stock)
works much better for dirt with lower gearing
 

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I'm planning to change my front sprocket teeth but absolutely have no clue to how will it affect my riding style or how it will affect to my engine on long run
If you don't know what the effect will be, I'm curious as to why you want to do this?
 

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I had never looked into it much, but someone in the engine braking thread said they went up to a 19T front sprocket on their Bonnie and it made accelerating and decelerating MUCH smoother. I was wondering what the exact trade off would be - wasn't sure if it was top end speed or acceleration. Sounds like it's acceleration speed. I think I could live with if it meant for a smoother all around ride. Am I understanding this correctly?
 

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Discussion Starter #7
If you don't know what the effect will be, I'm curious as to why you want to do this?
Newbonnie and BC sites says that if I go up a teeth it gives less vibration on to engine hence resulting in smoother ride.
I wanted to make sure from the riders who have done this before attempting to do on mine
 

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I put the 17t in my Scram. I love it! The down side is higher revs at cruise. That stupid bent locking washer can be a pain when changing. Also you have to readjust the chain tension. At first I thought the revs were the same. How could that be? The EFI bikes like mine have the speedo drive off the trans. It is reading rpm of the trans. I checked it against my GPS. I was now about 5 mph lower than indicated. If you have a front wheel speedo it won't be effected.

If you change it and don't like it, change back. No big deal.
 

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I put the 17t in my Scram. I love it! The down side is higher revs at cruise. That stupid bent locking washer can be a pain when changing. Also you have to readjust the chain tension. At first I thought the revs were the same. How could that be? The EFI bikes like mine have the speedo drive off the trans. It is reading rpm of the trans. I checked it against my GPS. I was now about 5 mph lower than indicated. If you have a front wheel speedo it won't be effected.

If you change it and don't like it, change back. No big deal.
I didn't know that bikes with the VDO gauges read speed off the transmission. My EFI Bonnie SE is an 09 and still has the old gauges. It reads speed off the front whee.
 
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