Sprocket adjustment from stock

[Commuter_Tim]

I want to convert the sprocket ratio on my CG, but I'm unsure where to start.

Reason being, the '98 POS has a smaller rear sprocket than the 91-98 model.

On my last CBT, the other lad was using a brazil model, with a larger rear sprocket.
I found that due to the sizing ratio, I could blast off away from him 0-40, but anything above that I struggled to keep up with him at all.

TL:DR how do I sacrifice some low end acceleration for top end speed? (from cursory reading, if I understand correctly it should be possible)
I'm aware its a CG, I'm not expecting much.

Is it as simple as ordering the Brazil set and installing as normal? or would the splines etc likely not match?
I'm in no hurry to break out the welder
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The above post is most likely nonsensical.

I ride a Bandit 600... badly.

[gbrand42]

For the same size front sprocket a larger rear will give better acceleration and a reduced top speed, whereas a smaller will have worse acceleration and a higher top speed (as long as the engine has the guts to pull the taller gearing)
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Yamaha RD50M, Honda C90, Yamaha RS100, Yamaha RD125LC, Honda XL125 V9 Varadero, Honda NT700VA, Honda VFR800X, Honda CRF1000L, Honda ST1300 Pan European

[Commuter_Tim]

Hmm, gonna be honest, I thought it worked the opposite way.

I guess I'm even more confused about it than I thought.

Is there a start point to look at, or some kind of sprocket teeth ratio chart?
Or is it all down to individuals knowledge? (seems a lot of things relating to bike mechanics are)
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The above post is most likely nonsensical.

I ride a Bandit 600... badly.

[Wull]

Its simples really,and as has been stated above

Smaller front and larger rear equals quicker acceleration and lower top end.

And then vice versa,and there's so many combinations you can try for.

I usually go for just -1 front sprocket which makes a good enough difference for me on the acceleration front,I did this on my vfr400 nc30,zx9r c1 and gsxr 1000.

If you go down this route it will throw the speedo out reading higher than it really should.
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"Scooters are for men who want to ride motorcycles but prefer to feel the wind on their vaginas"

[Kickstart]

Hi

Smaller front and / or larger rear means lower gearing, so more revs for the same speed. This will give you more umph at any particular speed in any particular gear, but also means you will need to change up at a lower speed (which loses you umph).

It will help in first gear (for the tiny time you spend in 1st), but the rest of the time you can probably just sit in a lower gear for the same effect.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[iooi]

[Taught2BCauti...]

I would start by finding what is actually available that will fit your bike - try www.jtsprockets.com
Don't jump sizes by more than one tooth from standard at a time, and bear in mind that the front sprocket is going to be more limited than the rear in the amount you can go up in size before the chain starts to hit something.

Changing the front sprocket can also cause problems if a chain slider is present - too big and the chain will whip, too small and the slider will be damaged.

Also, if your speedo is driven off the gearbox, this will affect the accuracy (not so if driven off front wheel).
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Honda Varadero XL125(V8)
www.TheFutureIsHere.eu

[Pete.]

I just did a search for CG125 sprocket sizes and came across this little gem of a reply from 4 years ago:

[Taught2BCauti...]

[Pete.]

BTW comparing the two models on motorcyclespecs:

95-97 model

98-00 model

The power, torque and weight are all similar and the only difference is 3 teeth on the rear sprocket. The later bike should out-accellerate your earlier bike whilst sacrificing top speed, with similar riders on board. If you are getting away quicker but losing out in the top I'd be lookng at your air filter.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Pete.]