Henry's Final Drive - Speedometer Adjustment Notes

[kwthom]

My Google-fu is a little weak at the moment, but the direct purpose of this specific thread is the following...

Last week, I emailed Dakota Digital & asked what specifically a single button press (up/down) indicated on the SIM-1A-GL speedometer correction device.

They're technical response: Maybe, depends on the speed you're doing as you are physically doing the adjustment. If you're close to 60MPH as you are adjusting, then it's close to one press equals one MPH This is because the processor uses the speed pulses to clock the adjustment. A fast pulse will see the speed adjust quicker. A slow pulse will see a slower adjustment.

Okay - well, it's not showing up when I need it (NOTE: I might have one for sale in a few weeks...) so I have a 12oclock Labs SpeedoDRD device in my hot little hand (thanks to that gray Amazon truck).

Now, I've done a fair bit of research in this forum and others, and I haven't found but a couple of values that seem to be a good starting point for not only the SpeedoDRD device, but any other speedo adjuster that uses a direct entry percentage value.



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The number I've seen is -13.0% or maybe -13.2% (those are negative signs) that will get a speedometer much closer with a Henry's Final Drive unit installed.

My direct request - simply a post that gives me what percentage value you used, what speedometer correction device you used, and whether or not you're using an alternate tire (70 series, non- standard tire, etc.) I'm simply trying to build a repository of values, and deriving a good 'first try this value...' for future installers of a Henry's drive.


Thanks much.

[kwthom]

...and all the King's horses / and all the King's men / tried to Humpty Dumpty / Back together again!"

NO!

I did - along with some help from my wife - put her back together again.

So, now that means I'm gonna haveta put on long pants for a test ride.

The last time I had long pants on was a month ago...

Details to follow...

[kwthom]

Done...for the moment.

The adjustment process? It's simple.

If you're using the SpeedoDRD device, here's what I did that nailed it on the second try.

* Install the SpeedoDRD device first, then program it to 00.0. Actually, install it, do the "SpeedoDRD Test Mode" process verifying you have it installed correctly. Once you pass this step, then do the "Factory Reset" process next.

* Ride your motorcycle (safely) on a road that you can monitor a GPS and get your bike up to 60 GPS MPH and keep it there for 15 seconds or longer. Once you do, set your cruise control, then read your bike's speedometer. Do it more than once; I did. Mine read right close to 50 MPH on all of the readings that I made.

I pulled into a parking lot, and made the adjustment. Attached to this is a 'cheat sheet' set of instructions I made for the field adjustments necessary.

I programmed in a +18.8% adjustment, as I thought I was reading a shade over 50MPH. I was off by about 1.5 MPH.

Next, a programmed setting of +20% was tried. I'm now +/- 1MPH between 10 and 70 for the bike speedo and the GPS. Cops and traffic prevent me from doing any more than that this morning; may have a window open up at lunch time to press it further a bit further out of town.

Fun little fact that I read from the 12oclockLabs web FAQ

"How accurate is 0.1% correction steps?
If you were traveling 60mph (or 60kph), 0.1% of that would be 0.06mph (or 0.06kph)
If you were traveling 200mph (or 200kph), 0.1% of that would be 0.2mph (or 0.2kph)
If you were traveling 300mph (or 300kph), 0.1% of that would be 0.3mph (or 0.3kph)
Thus correction steps of 0.1% are more than enough to get your speedometer more accurate than your gauge cluster is capable of displaying."

Done. Comments about the Henry's Final Drive as I get more miles on it.

[kwthom]

Done. Less than 1 MPH detectable difference @ 21.0%, up to 70MPH.

I'll get the 'break-in' gear oil drained, evaluated and replaced, then we'll check odometer accuracy.

Tomorrow.

[Rambozo]

You should check it at 200MPH just to be sure.

[kwthom]

You should check it at 200MPH just to be sure.

Sadly, the OE speedometer doesn't register a number that big.

The current gearing wouldn't even allow that bike to move that fast - unless it was tossed out of an aircraft.

Maybe.

[kwthom]

Time for a datapoint - how accurate is the odometer now? Prior to change, speed was dead-on, the odometer was off by +3.0% (100 GPS miles would read ~103 on the odometer)

Marked off by mapping and riding a 99.2 mile route. At the end, the bike's odometer was at 102.2...or 3% - no change (as expected)

This also gave me an opportunity to do a quick-and-dirty fuel mileage estimation.

At +5 over the posted speed out here in the desert, I'd get 36 or 37 MPG. With 200 miles and the reserve indicator on, I can dump +/- 5.5 gallons into the tank.

Well, my 99.2 mile route took 2.49 gallons, or 39.83 actual MPG. My speed was at or +5 to the white signs with the black numbers on them. The route was 95% Interstate highway.

Using the generous mileage from the odometer, it reads 41.04 MPG.

The last item will be to dump my bike's GPS data for the route and compare what I *think* the mileage was related to the *actual* mileage ridden according to the bike (which should be close).

Another time.​

[kwthom]

I got a chance to play around on some 7% and 8% grades a bit while getting a dose of handlebar therapy today.

The bike will certainly maintain a good 60 MPH without a lot of effort, but to do a lot more than that going uphill, give it up and click down into 4th gear. Oh, most of this road...you could have done a bit faster, but the original section of road I was on leaves zero room for error.

As mentioned in another thread, the difference in engine braking is noticeable. For those that tow, you might want to think about that recalibration of the butt-to-brain interface in those types of conditions. It certainly wasn't bad by any means, but if you were expecting that very light slowdown in 5th, it now happens in 4th.

I went well past the 'typical' mileage when the little light popped on letting me know there's ~ 1 gallon of fuel left. That three-ish MPG improvement is definitely there, even on a windier-than-normal day here in the desert.

Yeah...there's a Saddlesore 1000 ride I need to do (next week?) to really give this a workout.

My SpeedoDRD unit is having issues, I think. Tomorrow's task...