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Just recently went from the stock 17/41 sprockets to 17/45 on my 04 DL1000 I am really happy with the better response off the line and at low speeds. It also makes overdrive more usable. My problem as you have probably already figured out is the useless info I now get from my speedo/odometer. I know that the 650's use a pickup off the front wheel/rotor. For all you mechanical wizards out there, would it be possible to customize the front wheel of the 1000 to be able to utilize the 650's sensor/cable assy? If it is possible, would I also have to swap out the whole speedometer unit?
 

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Just recently went from the stock 17/41 sprockets to 17/45 on my 04 DL1000 I am really happy with the better response off the line and at low speeds. It also makes overdrive more usable. My problem as you have probably already figured out is the useless info I now get from my speedo/odometer. I know that the 650's use a pickup off the front wheel/rotor. For all you mechanical wizards out there, would it be possible to customize the front wheel of the 1000 to be able to utilize the 650's sensor/cable assy? If it is possible, would I also have to swap out the whole speedometer unit?
The Odometer and the Speedo are driven off the front sprocket. They are both run through the computer first, then output to the display.

You are in luck in one area though. The factory output from the odometer is accurate (pretty close anyway) with the 17 tooth sprocket. Since you did not change this, you are accumulating miles at the same rate you did before the change to the rear sprocket.

Most people get a speedohealer that either reprograms the computer or is an inline device that filters the input signal from the front sprocket sensor.

The bad news is that if you use the speedohealer, you will be adjusting the speedometer to be accurate but then throw off your odometer reading. It will begin to under report miles accumulated. This presents a whole different set of problems. So pick your poison.

My solution was to leave the ODO/Speedo alone and get a bicycle computer, install it and enjoy.
 

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FORUM GODFATHER.....R.I.P. PAT
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The Odometer and the Speedo are driven off the front sprocket. They are both run through the computer first, then output to the display.
Nope. That is only true for the 650(Dang! See edit.). The 1000 gets driven from the engine output.

Edit: I somehow read wheel instead of sprocket. I need to go to bed.
 

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Nope. That is only true for the 650. The 1000 gets driven from the engine output.
Then tell me what the sensor is that connects to the front sprocket on my 2003 DL1000.
 

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The Odometer and the Speedo are driven off the front sprocket. They are both run through the computer first, then output to the display.

You are in luck in one area though. The factory output from the odometer is accurate (pretty close anyway) with the 17 tooth sprocket. Since you did not change this, you are accumulating miles at the same rate you did before the change to the rear sprocket. ...
To expand on the front sprocket drive: since the speedo on the DL1000 is driven from the final drive (you can think of it as from the front sprocket as they are essentially the same thing) it effectively measures the rotation of the rear wheel (and assumes the rear tire is stock diameter as well) The calculation assumes that the ratio of the front sprocket to the rear is stock. Anything that changes this relation will make the speedo and odometer read differently from stock, it doesn't matter if the front or rear sprockets or both are changed, the effect is the same.

..Tom
 

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To expand on the front sprocket drive: since the speedo on the DL1000 is driven from the final drive (you can think of it as from the front sprocket as they are essentially the same thing) it effectively measures the rotation of the rear wheel (and assumes the rear tire is stock diameter as well) The calculation assumes that the ratio of the front sprocket to the rear is stock. Anything that changes this relation will make the speedo and odometer read differently from stock, it doesn't matter if the front or rear sprockets or both are changed, the effect is the same.

..Tom
Ok, so you are saying the miles reported by my ODO are off by the same percentage as the change between stock and 17/45?

EDIT: So the front sprocket is turning more often than it would normally because of the rear sprocket change? Based on the computer's ratio (formula), it thinks it has traveled more than it really has?
 

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Well you could always just put a GPS on the bike - then the speed will be correct, presuming you have a good satellite lock!! :biggrinjester:
 

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Ok, so you are saying the miles reported by my ODO are off by the same percentage as the change between stock and 17/45?

EDIT: So the front sprocket is turning more often than it would normally because of the rear sprocket change? Based on the computer's ratio (formula), it thinks it has traveled more than it really has?
If you start with the stock setup and check the Odometer and speedometer you will likely find that the two are each off by a certain amount. (I don't know what it is on the DL1000 but on the DL650 the Stock speedo setup reads optimitisc about 8%, while the ODO reads off around 1 or 2%. The difference between the ODO and Speedo will stay the same regardless of the gearing if you did nothing else. (On the DL650 Raceratb made a corrected faceplate that makes my Speedo read right on, but I don't think anyone did this for the DL1000.)

So if the new gearing makes the speedo read 9.75% higher then the result would be 108% times 109.75% and your speedo would now read 118.53% higherr than actual. An actual speed of 60 mph would now be shown as 71 mph.

If the odo was 2% optimistic than it would now be 11.945% optimitic. 1,000 miles actual distance would now show as 1119.45 miles travelled.

(It's early so quite possible that I made a simple arithmatic error so please anyone feel free to correct me.)

..Tom
 

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Then tell me what the sensor is that connects to the front sprocket on my 2003 DL1000.
You can see the electrical part of the sensor as it is bolted to the outside of the front sprocket cover and the wire runs up to and joins in with the stator wire loom. Inside the front sprocket cover the electrical part of the sensor reads off the castellated (sp?) nut mounted on the output shaft that the front sprocket mounts to. So, the speedometer/odometer actually read directly off the output shaft and how many rpms it is turning. That is why changing the front or rear sprocket will change the odometer/speedometer reading. Unless of course the ratio between the front and rear sprockets happens to be exactly the same.
 

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I wanted a little shorter gearing so I bought a 16t front sprocket for my Vee, and ran the stock rear sprocket. It is still geared pretty tall, but I am okay with it. The good part: I am able to see the speed well enough--the speedo is EXACTLY ten mph off--so when it says 70mph, actual speed is 60mph. Some see that as a nuicance but I can make the calculation easily--by now I'm used to it. And I have checked my odo, and it is very close to being accurate--so close as to be inconsequential. I am happy with the performance of this mod.
I rarely have to downshift when passing.

If I ever need a better speedo I will try the bicycle speedo idea. I am sure it will be good, just no ability to read it at night--otherwise, an effective solution.
 

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Thanks gentlemen. I still don't get entirely how changing the rear sprocket would affect the reading of the front sprocket (output shaft). But apparently it does. Seems to me that the computer would have to not only presume that the gearing is the same 17/41 with stock tire height, it would also have to compensate for each individual gear shift and then change the formula accordingly.

Is this correct? If so, this is an absurdly complicated way of coming up with odometer and speedometer readings.
 

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Seems to me that the computer would have to not only presume that the gearing is the same 17/41 with stock tire height, it would also have to compensate for each individual gear shift and then change the formula accordingly.
Not at all. The sensor reading comes after the gearbox so it doesn't matter what gear the bike is in. Besides, the computer is not involved in the speedo readout. The sensor wires go directly to the speedometer. The four pulses per sensor rotation doesn't need a computer to be translated to a speed reading. A single chip can handle that. Any changes to the relationships after the sensor will affect the speed reading including either sprocket, wheel diameter and tire aspect ratio.
 

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Thanks gentlemen. I still don't get entirely how changing the rear sprocket would affect the reading of the front sprocket (output shaft). But apparently it does. Seems to me that the computer would have to not only presume that the gearing is the same 17/41 with stock tire height, it would also have to compensate for each individual gear shift and then change the formula accordingly.

Is this correct? If so, this is an absurdly complicated way of coming up with odometer and speedometer readings.
It's actually quite simple. The output shaft (or front sprocket) turns in an exact ratio to the tire rotation. If you pushed your bike at a certain speed the front sprocket will always turn at a given percentage of the rear wheel rotation. (With 17/41 gearing the final drive is spinning 41/17 or 2.411 times for each turn of the rear wheel.) For stock sprockets and tires all it has to know is how many times the output shaft turns. Each turn will represent a certain number or percentage of wheel rotations and the speed and distance can be calculated from that. There is no reason to have any great error in the system but obviously manufacturers have decided to be a bit optimistic in the reading; and that's why most speedos are off a bit from stock.

Shifting happens before the final drive so the gear selected makes no difference. If we had a derailleur system like a bicycle then things would be different as the sprocket sizes change with gear shifts on them.

When you change the sprocket sizes (and/or the wheel or tire size) you are changing this ratio and that is what speedo healers change. Even there the system in concept is quite simple as all the speedohealers do is have the output of the speedohealer be a certain percentage higher or lower than the input.

As a side note, there are also two kinds of errors on an analogue speedo face like we have in the current Stroms.

One error would be a simple additive error. Say the faceplate of the speedo was rotated so that when you were stopped it read 10 mph. If the speed was otherwise accurate then the speed reading would always be 10 mph off. That is, when it said 20 mph you would be doing 10mph, when it said 60 mph you would actually be doing 50 mph. This can be cured in principle by simply rotating the face to line up at 0 mph. We generally don't have that error in any significance in our speedos.

The other kind of error, which comes with stock, is when the speed reading is a certain percentage off. For example, if it always read 10% higher than actual speed then if it displayed 55 mph the actual speed would be 50 mph, if it displayed 77 mph the actual speed would be 70 mph.

When someone says the speedo read "10 mph high" they are generally not giving all the information as the actual error will normally be a percentage difference. Is it 10 mph off at 50 mph or 10 mph off at 100 mph? If you don't say the speed the speedo is off at then you really aren't saying anything useful (and really you should be saying the error at two different speeds so we could tell if it was and additive error or a percentage error and it could possibly be both.)

..Tom

ps: as a footnote, the new 2012 V-Strom has the drive from the rear as well iirc, and is a digital readout. That means that DL650 riders will also have to deal with speedo healers if we change sprockets and/or if we just want a more accurate speedo.
 

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Well we should sticky this at my ignorance.

Thanks for the info.
 

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Discussion Starter #17
Original poster again: You are right about the offset, when my speedo says 78, I'm actually doing 65. Thats not the part that worries me. My odometer is off approximately 11% and that is what I'd like to fix. In my reading about the speedohealer I have assumed, maybe incorrectly, that it will not address the odo problem. That is why I was wondering about the Wee Strom setup.
 

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A speedohealer works on both odo and speedo. The error can be cured for either leaving the other ~6% off or averaged between the 2% odo error or the 8% speedo error.
 

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Discussion Starter #19
Thanks Pat. I guess I will add a speedohealer to my Christmas list since the riding season is just about over here. Thanks to all who posted. I learned a lot.
 

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jusspass...forget all the squawking and buy a SpeedoDRD...less expensive than a speedo healer and is very easy to set-up:

12oClockLabs

I also run 17/45 and dialed in a -16.9% correction. It seems to be dead-nuts on but I haven't checked via GPS (don't have one). But all the speed warning signs in construction zones seem to agree w/ what's indicated (althought there is variation among them).



If you change gearing again, just figure the amount of correction needed in the DRD; again - fast, simple, reliable and inexpensive!
 
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