The SpeedoHealer corrects for speedometer error that arises from the manufacturer's built-in error, sprocket changes, and tire wear. The unit can also do mph/kph conversion. I replaced my previous Yellow Box when a sample of Version 3.0 (SHv3.0-EXT) of the SpeedoHealer was provided for evaluation. This version features a remote switch and top speed memory capability readable with the bike in motion or after power has been shut down and restarted.
An excellent detailed description of the product and comprehensive web site for the SpeedoHealer can be found here.
Compared to the Yellow Box, the SpeedoHealer is much easier to install with no wire cut and splice required and features finer corrections with a 0.1% precision. Check with the SpeedoHealer web site or your local dealer for current pricing information.
The SpeedoHealer comes in a package as shown. The available Yamaha installation kit makes the job easy. I didn't use all those wire ties and that short length of wire shrink wrap is not used.
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Here is a close-up of the unit. The indicator LED shines through next to the switches. The connecting plugs fit in only one way.
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To begin the installation, place the bike on the centerstand and remove the seat. Then remove the right side cover.
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The provided installation wiring harness plugs directly into the stock speed sensor coupler under the right side cover. Locate the speed sensor coupler, push down firmly on the locking tab, and pull apart the two ends of the connector.
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Then plug the SpeedoHealer wiring harness into each end of the speed sensor coupler. It only goes in one way.
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At this point you can lay the SpeedoHealer anywhere on top of the bike, temporarily plug in the other end of the main harness as well as the long remote switch wire. Here you will test the unit and program it for your desired speedometer correction.
To test the unit make sure all the switches are in the down or OFF position and turn on the ignition switch. You should see the LED blink briefly. Turn off the ignition. You can now test the output of the unit by moving switch #1 to the up or ON position with all others remaining OFF. Turn on the ignition and you should see a speedometer reading of about 10 mph.
The linearity of the speedometer can now be determined. This isn't necessary to do as part of the installation but it serves as part of testing the function of the unit. Now press the remote button just once. The speedometer reading should fall to zero. Press the button four more times and the unit will now produce a frequency that can be registered on the speedometer. On my speedometer I register 9 mph at this output level. Press it again to double the frequency output and double the speedometer reading. Continue to press the button to double the frequency and the registered speed until the cycle resets. The last position is way off-scale (280 mph?). Turn off the ignition and return switch #1 to the down or OFF position when done. Don't leave the speedometer reading high values too long as the bike's odometer is racking up the miles just as if you were actually riding at that speed. This plot shows the results of my speedometer, quite a bit of nonlinearity at low speed (< ~10 mph) but linear at higher speed.
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Next, you must now program the SpeedoHealer for your desired speedometer correction. The first step is to determine the correction factor to use. The SpeedoHealer web site includes an on-line calculator to determine the proper correction factor. This calculator can also be downloaded for off-line use.
This shows the results of using the provided calculator.
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I had decided on a 2.5% optimism (+) factor for stock speedometer error. I found that the stock built-in error is not linear with speed and this value is a good compromise that provides sufficient accuracy at low as well as at highway speeds. I have almost new tires so I specified a low value for tire wear (1 on a scale from 0=new to 9=bald). Lastly, the effect of sprocket changes is computed automatically. I listed my 15/47 sprocket configuration from the stock 16/44 combination. I don't care about the odometer reading so I focused on speedometer correction. The result shows the speedometer error as well as the correction factor to program into the SpeedoHealer unit. These values are not the same. A speedometer that reads 55 mph where the true speed is 50 mph is 10% fast. The correction required will be 9.1% because the adjustment is applied to the higher, incorrect, value.
If you have a GPS and can accurately determine your actual and indicated speeds before installing the SpeedoHealer then you can use the 'Precise' mode of the on-line calculator to generate the correction factors. After installing the SpeedoHealer you can place the unit in transparent mode where no corrections are applied. To do this:
The total speedometer error is the product of the individual errors. For tire wear the error factor ranges from 1.00 for new tires (no error) to 1.02 (bald tire). For my setting of 1, the error factor is 1.00222 (add .00222 for each additional step). For the stock speedometer error the factor is 1.025. The sprocket error is (new rear x standard front)/(new front x standard rear) or (47 x 16)/(15 x 44) = 1.13939. The total speedometer error is then 1.17047 or 17.0%. The calibration value is then (100./1.17047) - 100. = -14.56405 or -14.6%.
If you press the 'Generate Instructions' button on the calculator, a sequence of steps is produced to make the programming easy. For my correction factor the steps are:
SpeedoHealer Calibration Value to be stored: -14.6%
The SpeedoHealer uses flash memory to store the programmed correction values as well as the top speed value so these can be preserved when power is turned off. The above steps should be followed carefully. In particular, when a switch is set to ON that must be done before the prior switch is set to OFF. That is because when all switches are OFF that is a signal to update the flash memory and exit programming mode. The LED will flash as you are doing this to indicate the current switch setting. If you accidentally flip the wrong switch ON in addition to the correct switch just switch the wrong one OFF again and proceed.
You can verify the programming by following this sequence. Nothing will be changed as long as you do not push on that button.
For a programmed value of 14.6%, switch #4 should produce a single flash, switch #5 should produce a sequence of four flashes while switch #6 should cause six flashes.
Having programmed the unit you can complete the installation and place the SpeedoHealer in it's permanent location. I placed it under the frame crossmember as shown. Velcro secures the SpeedoHealer to the undertail.
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The next step is to position the remote switch so it accessible while riding to take advantage of the rolling top speed retrieval feature. Pressing the button momentarily causes the top speed value stored in the unit to display briefly on the speedometer regardless of the current speed. The value can be reset by pressing and holding the button for two seconds. The long wire provided makes possible extending this all the way to the bars or front of the bike. The switch is very small and somewhat difficult to wield while wearing gloves though. There is also no other mounting method other than wire ties.
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I chose to install my own SPST (single pole-single throw) momentary contact switch from Radio Shack (about $2.00) and to place it on the left side cover so it could be pressed with the gloved left hand while riding. I didn't see any place up front that I liked better and probably won't be using this function too often anyway. I removed the left side cover and drilled the 15/32" hole the switch requires. The position of the hole allows the body of the switch to clear the inside wall of the side cover when installed. Thread the lock nut and washer on the cut remote switch wire, thread through the hole then solder the stripped ends on to the switch and add some electrical tape between and around the terminals for insulation. Complete the switch mount. I only trimmed a small length of the supplied wire and coiled the rest. The idea was to leave a length so that the side cover can be later removed and the long wire will permit separation of the side cover from the bike without having to disconnect the wire from the SpeedoHealer.
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The hole for the switch should also be such that the top of the switch clears the frame rail when the side cover is reinstalled. There should be sufficient clearance for the seat as well.
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Reinstall the left side cover, route the wire, and plug it into the SpeedoHealer.
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Lastly, reinstall the right side cover, replace the seat and go for a ride to make sure the speedometer and top speed reading display properly.
On my test ride I verified, using my GPS to compare speeds, that the correction factor used was appropriate. At 20 mph the reading was 0.9 mph reading low. At 40 mph it was 0.4 mph reading low but the difference dwindled to zero at 60 mph. I did not test above that speed but the trend indicates the readings would then be slightly high.
The top speed display function properly corresponded to the top speed indicated by the similar function on the GPS. The switch location is fine at a stoplight but requires hunching over slightly while riding at speed. Pressing and holding the button for two seconds does reset the top speed indication to zero.
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Last Updated: 04-30-2005
Copyright © 2001-05, Patrick Glenn, All Rights Reserved.
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