I swapped the stock 16-tooth countershaft sprocket for a 15-tooth on my '08 Aprilia Shiver. That makes the speedometer and odometer read about 6.5% high if my math is correct: (16/44) divided by (15/44). An EU company with an annoying Flash Website makes a gizmo called the SPEEDOHEALER for motorbikes and it allows one to correct speedometer/odometer error by -100% to +1000%.
I bought one from the USA distributor, and installed it. There is no special wiring harness for the Shiver, so I had to buy the SH-U01 Universal Harness Kit, and of course the SH-V4 Speedohealer itself. I had to figure out the wiring too, as the vendor's chart didn't have the correct wire color codes. Here's how to install one.
In my case, probably yours too, I had to remove the rear shock to get at the connector. Maybe a child or woman with small hands could reach the connector to release it, but you would want to make sure the exhaust and engine are cold!.
That meant jacking up the bike. I had a means to tie down the front end, but if you put a jack under the engine it wants to lift the front of the bike, not the rear. So I had to make a support, shown below.
I used a piece of 2"x6" and sawed 4 small pieces of 2"x4" and screwed them together as shown above.
Here's where it contacts the frame. There is just enough room to slide a small hydraulic jack under it. The spacers allow it to avoid putting pressure on the exhaust system.
That gave me slack to remove the shock (in my case, a Penske w/remote reservoir). Later in the process, you're going to need to be able to rotate the rear wheel, so you will either have to: reattach the shock, or do what I did and put another scissors jack under one side of the swingarm near the axle.
Here's a fuzzy picture of the speed sensor connector (pointed to by the red arrow). For reference, that's the oil filler cap in the lower left of the photo. Don't mistake the black wire behind the frame tube, that goes to the rear brake light switch.
First, you need to mount the Speedohealer itself. I put mine in the tray under the seat as shown above. I routed the wires down to the Aprilia's speed sensor connector using the obvious routing down the right side. That meant I cut about 12" of wire off the Speedohealer harness.
The Speedohealer comes with a push-button on a long wire harness that can be used to display the highest speedometer reading achieved. I don't care about that so I didn't install it (thus the empty connector to the right of the main connector in the photo above).
You can see the orange accordian water seal, and right above it is the flexible clip that holds the connector in place. You have to lift the lower end with your fingernail, or squeeze the upper end, then pull the connector straight up at about a 75 degree angle.
That's my shock dangling there. I probably should have removed it completely, as there isn't much room to work with.
The center of the three wires is the "signal" wire that the Speedohealer will intercept. The color codes for the Aprilia Shiver go like this:
| Aprilia Speed Sensor Wire Color |
Function | Speedohealer harness Wire Color |
|---|---|---|
| Orange w/Red | +12V | Red |
| White w/Gray | Signal | White (to connector) Green (to other end towards ECU) |
| Brown w/Black | Ground | Black |
The Speedohealer directions are quite clear, once you know what the proper wire colors are. I cut the white w/gray stripe wire and soldered the white Speedohealer wire to the short end coming out of the Aprilia's connector. The other end of the white w/gray stripe wire I soldered to the Speedohealer's green wire. For the power and ground I just scraped away enough insulation to be able to solder the appropriate Speedohealer wire without having to cut those two wires of the Aprilia's connector.
Then I followed the Speedohealer's directions for testing the installation (which involves rotating the rear wheel by hand). All checked out, so I wrapped the soldered joints in good grade electrical tape (Scotch 33) and then wrapped the whole harness to make it look cleaner.
| ( | 15 x 44 ———— 16 x 44 |
- 1.05 | ) | x 100 = -11.2% |
I have a Garmin 276C mounted on my Shiver — I used it to imperically determine that I really need an -10.3% correction factor. My GPS said 60mph when the speedo said 67, and 70mph when the speedo said 78mph. That works out to about a 10.3% difference, so that suggests that the stock Shiver speedometer is about 4% optimistic. I dialed in a -10.3% correction, and now my speedometer agrees perfectly with my GPS.
No big deal. It's a good mental exercise to always count (silently) the gear changes so you know what gear you're in. The more you practice it, the more automatic it becomes. After a few years, you just "know" what gear you are in without even realizing that some part of your brain is keeping track!
Copyright © 2009, by H. Marc Lewis. All rights reserved.