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Posted
To each, his own. But from what I read here, a speedohealer doesn't solve the problem so why waste the money?

 

If I know that when I'm showing 70 on the speedometer, that I'm really doing 65, then HELLO, I am going to pull that information out of my brain and leave my money in my wallet.

 

Am I missing something, or is that just not high tech enough?

 

Somebody clue me in, please.

 

Jeff

For me personally, the odometer is not an issue is much as I want my speedometer to be accurate. It's annoying that I've got to show one thing to do another.

  • 1 month later...
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Posted (edited)

I am getting ready to order a SpeedoHealer and was wondering whats involved with setting it up? I don't have a GPS so is it a simple as setting the correction at 7.5% and getting someone to follow in a cage to check the accuracy and hope the cage is accurate ? There aren't any mileage markers around here so thats not an option. looking for ideas...

 

Thanks

Keith

Edited by KeithR
Posted

It's fairly simple. I think that 7.5 will get you close enough. You can test it then by going for a ride and checking it against the mileage markers on the highway. Just sit it on 60 MPH and use your second hand or a stop watch to verify that it takes 60 seconds. Best to check it over a span of several miles as the markers are not always dead on. You will be very close though.

Posted

It is a personal preference thing - my preference is for my speedometer to accurate. I've seen the 7.5 figure tossed around but I assure you mine was just over 9% off and it is now about as close to exact as a speedometer can be. The speedohealer was worth the cost and easy to install.

Lynn

Guest tx2sturgis
Posted
I am getting ready to order a SpeedoHealer and was wondering whats involved with setting it up? I don't have a GPS so is it a simple as setting the correction at 7.5% and getting someone to follow in a cage to check the accuracy and hope the cage is accurate ? There aren't any mileage markers around here so thats not an option. looking for ideas...

 

Thanks

Keith

 

A few options here. Maybe you can borrow a handheld GPS from someone you know. With a neck lanyard, its easy to use for this kind of test. You COULD buy a cheap one, test it out on the bike, then return it...not the best way to do it, but possible. Or you could find a helpful radar cop, tell him youd like to know your exact speed as you pass his cruiser!

 

:scratchchin:

 

 

Hey you wanted options!

 

 

Posted

If you have a Tach on your bike you could simply go off of the engine speed at a given velocity and then do the simple calculation using the known gear and final drive ratios... But that requires that you have a tachometer.

 

I am getting ready to order a SpeedoHealer and was wondering whats involved with setting it up? I don't have a GPS so is it a simple as setting the correction at 7.5% and getting someone to follow in a cage to check the accuracy and hope the cage is accurate ? There aren't any mileage markers around here so thats not an option. looking for ideas...

 

Thanks

Keith

Posted
What proof is there that a GPS is 100% correct?:detective:

 

Well... They aren't 100% correct. (I calculated 99.84%)

 

Last time I worked out the details with reasonable assumptions based on a GARMIN unit, taking specifications from the manufacture, as well as the other necesairy relativistic corrections and assuming the standard GPS signal frequency of 1.575 GHz... I wound up with determining an accuracy of 0.16%

 

Part of the assumption is that it is a perfectly clear day i.e. no additional E&M interference with the signal, and that the unit is moving at a constant speed (in all 3-dimensions).

 

If you really want to know all of the gory details, I'd be happy to go through them, but it would take me a while to type all that junk out...

 

So... yea, I just confirmed my nerdhood - but as a PhD Student in Physics I don't have much of a choice...:happy34:

 

- Rick

Posted

Can you find a trooper or deputy that will clock your speed. That's what I did after installing mine. We checked it at 60 and at 70 mph to dial it in.

Posted
Can you find a trooper or deputy that will clock your speed. That's what I did after installing mine. We checked it at 60 and at 70 mph to dial it in.

 

GPS is really accurate. I was pulled over last summer on the freeway and the cop asked me how fast I was going.

 

Me - I was going 71 officer.

 

Cop - That's nice but the speed limit here is 55.

 

Me - Doh!

 

His radar detector and my GPS were perfectly in sinc. :whistling:

 

Got a ticket for going 71 in a 55.....

Posted

I guess I have a really weird bike, My speedo is only 1 mph slow at 70 according to GPS. and in 10.1 miles the odometer is dead on with the GPS. :happy34:

 

How accurate is my GPS? :think:

When I first got it (a cheap Garmin) it showed 99.9 miles when I passed the 100th mile marker on I55.:p

Guest tx2sturgis
Posted

I found this installation guide for a RSTD. Looks fairly easy!

 

Its VERY easy to install.

 

Calibrating it, if you want it exact ( more or less) may take an hour or so, but hey, you'll actually be RIDING the bike, so its all good!

 

If you do the GPS calibration procedure, its a good idea to take along a pen and paper to write down the calibration figures as you go along. Sometimes its kinda hard to remember where you last set the reading, and how far off it was, and which way you want to go with the numbers. At least, thats what I did, and it helped.

Posted

I ordered a speed-o-healer and set it to 7.5% according to Freebird's post.I think it is

pretty close.For the ones that have set their's with the GPS,what RPM are you running

at 60 MPH.Mine is turning about 2900 RPM at 60 MPH with a Drag Specialities Tach.I know its not an exact science with out a GPS,but if they are all geared the same,then they should be running the same RPM at the same MPH.

Posted
I've wondered that as well. Seems like they should be able to get this right.

 

Now that I have a GPS, I don't even look at the bike speedometer anymore.

 

 

Same here! I set my speed by the GPS.

  • 2 weeks later...
Guest tx2sturgis
Posted
This is only true if the bike idles at the same rpm. Also, there will be [slight] variations based on air cleaner condition, type of fuel/octane rating, spark plug/ignition efficiency, how well the carbs are tuned, etc.

 

but -- the Idle is the big thing...

 

Idle speed is NOT related to a given road speed vs the engine RPM...Just FYI.

Guest tx2sturgis
Posted
..... if they are all geared the same,then they should be running the same RPM at the same MPH.

 

More or less, they will be, other than the slight differences in tire diameters, they will be very close. Trouble is, you run into discrepancies with the different tachometers used. Some of these are only 'in the ballpark' as far as accuracy goes.

Posted

Well crud, You are 100% correct... since the drive shaft doesn't care what the vehicle idles at... I don't know where my brain has been lately

 

 

Idle speed is NOT related to a given road speed vs the engine RPM...Just FYI.

Posted
For me personally, the odometer is not an issue is much as I want my speedometer to be accurate. It's annoying that I've got to show one thing to do another.

 

I am kind of like jfoster. I have always been a little anal about time and speedometer accuracy. In my past jobs I was responsible for a lot of gage calibration and I am the same way about my speedometer. I want it real close. I have checked my 83 many ways and it is on the mark. It used to be off about 3mph and I took the speedometer out and reset it.

Most mile markers are pretty close as long as the measured mile is in a straight line, but a long sweeping curve in the mile can make a difference according to which lane the measurment was taken from.

With a stop watch and a mile marker, you can check your speed at any speed, but doing 60mph does give you 60 seconds. But, if you measured 49 seconds, you would be doing 73.5mph. This would be 60 divided by 49 times 60 equals 73.469.

RandyA

  • 2 weeks later...
Posted

Not really. First of all, there is really no room for a larger tire. Secondly, it would take a MUCH larger tire than you could fit to make up the disparity. The Speedohealer is really the only solution and it is very simple to install.

  • 8 years later...
Posted

That's good because none of the units allow to you to adjust both separately. You can choose to get one or the other dead on or find a compromise somewhere in between that suits you. I agree with you though, I prefer that my speedometer be dead on.

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