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Main Area => General GS500 Discussion => Topic started by: Pigeonroost on July 26, 2008, 08:02:02 PM

Title: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on July 26, 2008, 08:02:02 PM
Through the search feature, I found a thread on this board from about two weeks ago on this subject; but no solution other than using a GPS as the speedometer.  The GS500F is my daughter's bike and we road together today.  We were on back roads and even though I was just puttering about, I kept running away from her.  We stopped for a rest and I asked why she was riding so damned slow; "But I was pushing the speed limit, what do Ya want?"  Actually, I was under the limit by quite a bit and leaving her behind.  My bike has an electronic speedo/odo and a calibration device installed to be dead nuts on with GPS.  I understand this bike has a front wheel driven mechanical speedo/odo; is that right?  What could I do other than use a smaller front wheel -- and it seems to be at least 10% off, that would be a pretty good step down in tire circumferance.  Any fixes to offer?

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: gsJack on July 26, 2008, 08:44:17 PM
That's about average for a GS500 speedo, both of my GSs were about 10% high.  You want a larger front tire to fix it.  A 110/80 in place of the 110/70 will cut that in half or better.  My 02 GS speedo seems to be only about 1 mph off at 40 mph now with a 110/80 tire as checked by those police radar carts placed by the roadsides.  I haven't bothered to check it at higher speeds since I don't have a GPS.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: the mole on July 26, 2008, 09:10:16 PM
Jack is right, you need bigger diameter tyre to make the wheel rotate slower at the same road speed. Mine is also 10% out, and its annoying but at least you're less likely to get booked speeding.\. :thumb:
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: sledge on July 27, 2008, 12:40:23 AM
You might find this interesting... http://home.jtan.com/~joe/speedo.htm  cant say if it will work on the GS though.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on July 27, 2008, 08:13:11 AM
Sledge; that is very interesting, but really tedious!  I guess a Zumo GPS is in this bike's future.

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on July 27, 2008, 08:14:12 AM
Mole and Jack;

Thanks; I wuz bassackward fer shure.

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: NEWGS500F on July 27, 2008, 08:31:14 AM
A simpler, easier and cheaper solution is to grab a cheap push bike computer, a rare earth magnet (to replace the one they give you with the bike computer, generally too small and weak for a motorbike) and install this.

I done this just last week.  Once you put in the correct circumference for your wheel, the speedo will be bang on and as stated, the stock GS speedo IS off, reads to high.  That said, the bike computer I got wasnt the best and cuts off at 65ish mph!! However, better computers are available, same setup and I believe they wll accurately read up to 180mph ish!!!

So...its an easy alternative, takes 5 mins to install and also does other things such as clock, thermostat, etc etc

Just a thought,
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: tripleb on July 27, 2008, 10:59:42 AM
I know exactly what you should do...Buy a sigma bicycle computer for $30 and some rare earth magnets and your  problem is solved.  Much cheaper and easier than a GPS.  the sigmas reed up to over hundred mph so you should be fine with it on this bike.  Here's a link to one for $27.50 USD - http://www.wiredbike.com/shop/product.php?productid=7446

I did a thread on it a while back... http://gstwins.com/gsboard/index.php?topic=38219.0
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: theUBS on July 27, 2008, 08:52:15 PM
I might just be out of my miind, but I just ride at a higher indicated speed.  I actually find it somewhat refreshing to feel like I'm getting away with something!  :icon_mrgreen:  I guess it would be nice to have the precision though--especially if it doesn't cost much.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on July 28, 2008, 09:31:21 AM
Tripleb;

That is a Cracker Jack of a good idea!  Got one ordered.

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on August 04, 2008, 10:53:40 AM
Recieved my Sigma BC160BL today and have it programmed and ready to install when I get off work.  I made the wheel diameter a nice round figure of 1.8 meters and will tweek that as needed to match a GPS I can get from another bike.  This thing looks too good to be true.

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: theUBS on August 04, 2008, 04:20:46 PM
Quote from: Pigeonroost on August 04, 2008, 10:53:40 AM
Recieved my Sigma BC160BL today and have it programmed and ready to install when I get off work.  I made the wheel diameter a nice round figure of 1.8 meters and will tweek that as needed to match a GPS I can get from another bike.  This thing looks too good to be true.

prs

You should document it for us! 
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Paulcet on August 04, 2008, 04:35:09 PM
Dgyver put SV gauges on the '97 I bought from him.  Checked speedo accuracy today with a GPS and found it to be only about 3-4% optimistic. 

What say you, D?  Did you do anything special when you adapted the SV speedometer to the GS?
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: dgyver on August 04, 2008, 05:39:51 PM
Quote from: Paulcet on August 04, 2008, 04:35:09 PM
Dgyver put SV gauges on the '97 I bought from him.  Checked speedo accuracy today with a GPS and found it to be only about 3-4% optimistic. 

What say you, D?  Did you do anything special when you adapted the SV speedometer to the GS?

Nothing other than making a spacer for the SV speed sensor to fit on the GS axle. Differences in tire diameter will affect the indicated speed.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on August 05, 2008, 06:16:28 AM
I got side tracked last evening (I would rather take a beating from a young Iron Mike than to go grocery shopping) and did not get to tinker with the bike.  When/if I do get 'er dialed in, I will report on the settings and accuracy.

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: tripleb on August 05, 2008, 06:34:58 AM
Make sure you roll out your wheel diameter.  I tried the conversion method and it didn't work as well.

Check my thread for the diameter I actually used versus what my calculation said it should be.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on August 05, 2008, 08:24:35 PM
tripleb;

I reckon I owe you tuition because I have tried to learn from your posting.  I programmed mine when it came in the other day and I rounded up your figure to 1800mm for my initial testing.  I also followed your lead to use the round inexpensive magnet instead of the bicycle spoke clip-on provided.  I did the initial install this evening.  I used the provided handle bar mount and rubber "O" ring to place the unit next to the inner left grip (bud did not expose the sticky tape - yet).  The feed cable runs along the choke cable to the speedo cable and through the first cable loom.  I made two wraps around the post that holds my left reflector.  I drilled two small holes just fore and aft of the left fork slider tube and at a height to match the inner flat of the rim (where your nice photo shows your three stick on balance weights.  I had to use a larger "O" ring than supplied to go around the fork slider tube and through the holes I drilled to hook to the sensor (actually I just looped two of the supplied ones together).  Then I used JB Weld to coat the back of the round magnet (I actually took care to match polarity of the magnet to the that of the one supplied -- but I bet that makes no difference at all) and I glued it to match the heavy spot of the rim (or yellow dot of the tire), but that was likely folly too since the magnet only weighed 90 grains, but if it vibes out of balance I will stick on a matching tid bit of lead weight opposite or go with dyna beads.  JB should be cured by tomorrow evening for a test ride and calibration check/adjustment.

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: tripleb on August 06, 2008, 06:17:29 AM
sounds like you did a better and more thorough job than I did.  Good luck :thumb:
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on August 06, 2008, 07:41:03 PM
Well; I'm impressed!  The Signa BC 1606L worked tickie-boo.  I took the Garmin Zumo 550 GPS off of my Gold Wing and used its suction cup mount upon the bezel/lens of the GS500F's tach.  I went on a test ride with the bike calculator set as noted above (front tire diameter at 1,800mm for the new B'stone OE BattlAx tire).  At a steady travel rate of 70 mph on the Garmin unit, the BC1606 read 69.5 mph.  The OE Suzuki speedo was reading about 78 to 79 mph.  I made a stop and re-entered the front wheel circumference as 1818mm (a 1% change) and then the long term bike calculator indicated speed was right on with the GPS.  The Garmin went back on the Wing and the GS500 has an accurate speedometer, trip meter, clock, trip duration, and what not.  The price was very good on this easy project too.

I did make a blunder and those who follow can learn.  As I described above, I used JB Weld to set the round magnet to my rim.  That worked great; but my placement of the magnet relative to the induction pick-up did not allow the signal to register -- my gap was too wide and the orientation was 90 degrees wrong.  I used a small chisel and hammer to break the magnet loose from the wheel.  True to JB Weld's reputation, the glue did not break or peal away from the wheel, the paint on the wheel came off with the glue and magnet.  I then prepped the wheel again and re-glued the magnet with 3-M auto trim adhesive (fully sets in 10 minutes), the location was the outside surface of the rim's bead seats.  Then the gap was less than 5mm and the new speedo registered flawlessly.  A little Dupli-Color flat black wheel paint and no one will know the difference ;-).  I liked the handlebar location right up against the inner end of the left grip and I will prep the handlebar and pull the self stick adhesive backing off of the mount.  Much thanks to tripleb for the suggestion, pointers, and starting wheel circumference figure.  I was and may re-glue the magnet with JB again, but the 3-M stuff has it very well stuck right now - good 'nuff.

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: tripleb on August 07, 2008, 07:23:47 AM
if you use rare earth magnets, you can use 2 magnets (instead of one) to close the gap.  You only need to glue one to the rim and the other will stay on by itself since they're so strong.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: drowningbird808 on August 07, 2008, 09:23:36 AM
i got pulled over doing 55 in a 35 the other day and my speedo said 55 on the dot... :dunno_white:
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: dgyver on August 07, 2008, 09:36:39 AM
Quote from: drowningbird808 on August 07, 2008, 09:23:36 AM
i got pulled over doing 55 in a 35 the other day and my speedo said 55 on the dot... :dunno_white:

That is one way to check your speedo... not a good way though.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Pigeonroost on August 07, 2008, 11:37:39 AM
OOOOOOOOOOOOOO.......  20 over............. CHING!

Time for radar detection and pealed eyeballs.

prs
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: DoD#i on August 07, 2008, 11:52:03 AM
Quote from: Pigeonroost on August 07, 2008, 11:37:39 AM
Time for radar detection and pealed eyeballs.

There is another method.  :laugh:

Cheap, easy, immune to RADAR, VASCAR and LIDAR.

Look up and to the left just a touch for this shocking secret.  :o
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: tripleb on August 07, 2008, 12:14:50 PM
sorry, I got the need....the need for speed!

I know that was corny, but I couldn't resist
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: kitten_mittons on August 26, 2011, 08:17:49 AM
So. . . I've been searching the forums for this topic as I would like the speedometer to just show correctly rather than use a GPS or a bike computer (because I'd like the odometer and trip to read correctly as well.)  If I take it to get it calibrated, will it fix this, or is it just always going to be off?
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Yuri. on August 26, 2011, 12:25:12 PM
Quote from: kitten_mittons on August 26, 2011, 08:17:49 AM
So. . . I've been searching the forums for this topic as I would like the speedometer to just show correctly rather than use a GPS or a bike computer (because I'd like the odometer and trip to read correctly as well.)  If I take it to get it calibrated, will it fix this, or is it just always going to be off?
Then you don't need to do anything.
I've installed a sigma bike computer, and while the speedometer is about 8% over the real speed, the odometer and trip meter are pretty accurate.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: kitten_mittons on August 26, 2011, 12:41:02 PM
Quote from: Yuri. on August 26, 2011, 12:25:12 PM
Quote from: kitten_mittons on August 26, 2011, 08:17:49 AM
So. . . I've been searching the forums for this topic as I would like the speedometer to just show correctly rather than use a GPS or a bike computer (because I'd like the odometer and trip to read correctly as well.)  If I take it to get it calibrated, will it fix this, or is it just always going to be off?
Then you don't need to do anything.
I've installed a sigma bike computer, and while the speedometer is about 8% over the real speed, the odometer and trip meter are pretty accurate.
Oh, it seemed my odometer was off, maybe it's just me.  I'll have to go test it over the weekend.  Thanks for the help.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: crzydood17 on August 26, 2011, 06:23:44 PM
this might be hard but why not use a GPS to get accurate readings and mark them on the speedo window... then design a augmented speedometer gauge. This can be customized and adjusted for whatever % off you are...
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: mister on August 27, 2011, 12:56:42 AM
My ODO is accurate, speedo reads higher than actual. So if I do a tad higher than speedo I am still Probably safe, and doing what speedo says means no way can I get booked for speeding. I don't see this as a big issue - now if it read lower than actual, then yeah, you got problems...

Michael
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: runabout879 on August 27, 2011, 01:45:19 AM
I was wondering if this might be the case after following my wife and getting onto her for doing 80 down the highway. She said she was only slightly over 70 on her speedo, which I know shows a few miles higher than actual, checked against 2 different GPS units.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: kitten_mittons on August 27, 2011, 06:39:42 AM
Quote from: runabout879 on August 27, 2011, 01:45:19 AM
I was wondering if this might be the case after following my wife and getting onto her for doing 80 down the highway. She said she was only slightly over 70 on her speedo, which I know shows a few miles higher than actual, checked against 2 different GPS units.
Yeah, I'm assuming it's the same issue. I was driving about 75 on the interstate and was getting passed by everyone.  Needle gets pretty jumpy after about 65 as well.  I'm pretty new to motorcycle riding (got my bike around a month ago) so I really do not know a lot about my bike yet.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: runabout879 on August 29, 2011, 05:59:44 PM
Quote from: kitten_mittons on August 27, 2011, 06:39:42 AM
Quote from: runabout879 on August 27, 2011, 01:45:19 AM
I was wondering if this might be the case after following my wife and getting onto her for doing 80 down the highway. She said she was only slightly over 70 on her speedo, which I know shows a few miles higher than actual, checked against 2 different GPS units.
Yeah, I'm assuming it's the same issue. I was driving about 75 on the interstate and was getting passed by everyone.  Needle gets pretty jumpy after about 65 as well.  I'm pretty new to motorcycle riding (got my bike around a month ago) so I really do not know a lot about my bike yet.

I did a follow-up check using my GPS unit, and it seems to be about 15% off. Or, if you have to adjust it down from indicated to actual, it's a 16% adjustment. At 80 indicated, I was actually running 75. I almost lost my GPS in the process of checking this, as the suction cup let go of the tach lens running at 75mph. Luckily, I still have fairly good reflexes from time to time. My wife would have killed me had I lost it, since I haven't even had it for 2 weeks yet.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: numus on August 29, 2011, 09:50:54 PM
My speedo read 0 the other day.. granted that was because i forgot to tighten the cable down and it came undone...
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: grader on August 29, 2011, 09:51:31 PM
your math just aint right. 80 indicated and 75 actual is just over 5%, not 16%. your speedo is actually pretty close close compared to many others on here.
Title: Re: Speedometer greatly over estimates - can I calibrate it?
Post by: Phil B on August 30, 2011, 07:07:59 AM
Do it "old school". no money expenditure required, other than gas:

Find a place where they have "odometer check" markings on the freeway.
(you know, "1 mile, 2 mile" thingies)

Go drive 1 mile at "60 miles an hour".

Tweak speedo, until "60 miles an hour" takes you exactly 60 seconds.