Changed gearing, speedo reads same?

Hi guys this is my first post, thanks for any help. I have a 09 1250 Bandit, and went to a 45 tooth rear sprocket, stock 18 tooth front. The bike is showing the same mph at the same rpm as it did with the stock gearing. How can this be? By feel the bike is obviously turning more revs at any speed than it was with stock gearing, and accellerates much harder. I am looking at speedo healers from Dale Walker and Sprocket Center.Does anyone know which of these is easiest to hook up the wiring, and figure out the correction settings? Do either of these just plug into existing plugs on the bike, or do they require splicing? Thanks for any help. Paul.

It's my guess the Suzuki gets the speed from your gear box and not your wheel. My Yamaha does the same. If your speedo got its information from the front wheel then it would definitely change with a gear change. Take along a GPS and you'll see what your actual speed is. At 70mph indicated I'm doing about 65/66mph actual (according to GPS). That's normal for the Yamaha FZ6.

A speedo healer would fix the discrepancy and should be a direct plug in, I know they are with the Yamaha. You'll need to know the percentage of error, somewhere in the 6-8% is my uneducated guess. Someone will chime in that has a Bandit and knows more about them. I know that if I went from a stock 16T front sprocket to a 17T my speedo would be almost spot on. I will do that eventually.

Yes, the speed is read from the a little sensor off the countershaft sprocket. Check your speed against a GPS or a timed mile and compare. As mentioned a Speedohealer will work. The stock speedo is off anyway from the factory by at least 5-7%. It reads higher than actual and now you are likely to be about 10% off.

One thing I see not mentioned with the Speedohealter is that your mileage on the ometer will be off at what ever you set the healer at. Ditto when you go to a different gearing. I've been running one on my 07 Bandit for near 45,000 miles now. I've had it set from 7.5 to 6.6 precent. Different rear tire brands , a little difference in the circumference even though they are suppose to be the same.

I don't think there is a way to adjust the ratio between the speedo reading and the odometer relationship. The one signal supplies them both. So choose which one you want to be accurate; speedometer or odometer. I typically rely on the GPS for steady cruising.

Most motorcycles accelerate so quickly that the refresh rate of most GPS units won't keep up with the acceleration capability of the bike. On my SV1000, I watch the numbers grow by big leaps, 2, 35, 69, 88, etc. Easy to get a ticket if just relying on the GPS while accelerating.

Day Trippin said:

I don't think there is a way to adjust the ratio between the speedo reading and the odometer relationship. The one signal supplies them both. So choose which one you want to be accurate; speedometer or odometer. I typically rely on the GPS for steady cruising.

Most motorcycles accelerate so quickly that the refresh rate of most GPS units won't keep up with the acceleration capability of the bike. On my SV1000, I watch the numbers grow by big leaps, 2, 35, 69, 88, etc. Easy to get a ticket if just relying on the GPS while accelerating.

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OOppppss!

It just amazes me why most bike companies think they just have to make the speedos read 6 to 8 mph faster. And, auto / truck companies don't. Even my BMW motorcycles were off 7 to 8 mph at 70 mph cruising speeds. But, on the R11**GS, you could change the front wheel speedo hub out with one off the R11R (19" front vs 17" front ) and it would only be 2 mph off.

achesley said:

It just amazes me why most bike companies think they just have to make the speedos read 6 to 8 mph faster. And, auto / truck companies don't. Even my BMW motorcycles were off 7 to 8 mph at 70 mph cruising speeds. But, on the R11**GS, you could change the front wheel speedo hub out with one off the R11R (19" front vs 17" front ) and it would only be 2 mph off.

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Well,Andy, I was all set to blame it on the Metrick conversion their engineers used until you said your BMW was only off a hair. Oh well, at least spedo healers are available to fix it no matter what! Now if my allowance would just cover the cost of one......................................

Dave.TX said:

It's my guess the Suzuki gets the speed from your gear box and not your wheel. My Yamaha does the same. If your speedo got its information from the front wheel then it would definitely change with a gear change.

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If the speedo reads from the front wheel, it matters not what you do at the back because the front wheel rotation speed will not change. The only thing you are changing when installing different sprockets is the ratio between the engine and the back wheel .

The speed sensor is mounted on top of the front sprocket. The bike does not get speed from the front wheel. Changing the front sprocket lower a tooth or going up teeth on the back sprocket will make the speedo read more optimistic than it does from the factory.