Odometer mileage and speed not correct due to larger sprocket

[jamedawg32]

Hey there I have a 2006 GSX-R that i just recently bought. I was aware that the previous owner had put a larger sprocket on the bike because he was into stunting and stuff like that and I was told how the speedometer would read about 20mph faster then what your really going but i didnt know and didnt relize till I checked that the mileage is actually turning faster then it should. I calculated a trip in my car of 3.2 mile and then on my bike i did and it showed 4.5 mile for the same distance. I guess, say if im going 40 but the speedometer is dreading 60 its racking up the miles like im going 60. I ride my bike alot so I dont want to be racking up all them extra miles. Any help or suggestions of what I need to do or what my options are???? I would like to keep that sprocket on there but dont know if there is any way around racking up the extra miles like that. Please help. Thank you.

[Clint]

Put on a tiny sprocket for a while? Honestly, if you're running a big sprocket, you're revving the engine higher at cruise and shifting more often, so the indicated mileage is a fairly accurate measure of the bike's usage. But you don't want to hear that.

Not sure what a good solution might be. Welcome to M-J.

[Easy Rider]

Originally Posted by Clint

Not sure what a good solution might be. Welcome to M-J.

If his description is accurate and the speedo/odo is actually driven off of something in the transmission (on the output shaft), then the only solution would be to find that mechanism and change the gear on IT.
BUT.......
I find the whole story to be suspect. Not that one doesn't exist but I have never seen a bike where the speedo/odo wasn't driven by a gear or sensor on one of the wheels.......in which case, the sprockets, chains or even transmission internals have no impact on the speed/distance measurement. In that case, the diameter of the wheel/tire makes a difference.

Am I about to learn something new today ??

[Aussie Steve]

The Bandit runs a sensor at the gearbox sprocket this runs the speedo. I would suggest disconnecting the sensor...wherever it may be for a short while to compensate for the faster reading. You will, of course have no idea of how fast you are riding whilst it is disconnected and you run the risk of getting speeding fines and having your bike stickered for faulty equipment.

Good luck

[Easy Rider]

Originally Posted by Easy Rider

Am I about to learn something new today ??

Originally Posted by Aussie Steve

The Bandit runs a sensor at the gearbox sprocket this runs the speedo.

Yep. Sure enough.
Probably a more reliable arrangement but certainly not very flexible.

In that case, I suggest you put it back stock.

" I ride my bike alot so I dont want to be racking up all them extra miles."......and some extra wear on the engine too......and worse gas mileage too.

[jamedawg32]

first I want to say thank you for the replys and also want tonsay that what I've have said is true and accurate i would not make any false statements my goal is just to find out the problem and what I need to do to fix it. I was told by a friend that at the Suzuki shop there is some sort of mechanism that will adjust your odometer to what sprocket you have on it so I might try it cause my milesnare going to rack up real quick and I can't have that but If anyone has any questions or can help me out anymore please help me out thank you

[jamedawg32]

I just seen the last reply is this larger sprocket also hurting my gas mileage?

[Easy Rider]

Originally Posted by jamedawg32

I just seen the last reply is this larger sprocket also hurting my gas mileage?

Yes.......and it causes your engine to rev. higher than "normal" thereby causing increased engine wear......but you probably won't notice the results of that for a LONG time.

If you do decide to change the rear back to stock, probably should do the front sprocket and chain at the same time. Might save you some grief down the road.

[DrBob]

There are aftermarket adapters you can get for your electronic speedometer that will correct the error. One brand name that comes to mind is "speedomender". They are easy to install, and usually cost less than $200.

My old shovelhead has a mechanical speedo driven my the transmission, so when I changed sprockets I have to have the speedo sent off to a guy in California to have the physically altered for the new ratio. Trust me, compared to the cost of that, your plug-in speedo correction module is a bargain.