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

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.

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.\.

You might find this interesting... http://home.jtan.com/~joe/speedo.htm  cant say if it will work on the GS though.

Sledge; that is very interesting, but really tedious!  I guess a Zumo GPS is in this bike's future.

prs

Mole and Jack;

Thanks; I wuz bassackward fer shure.

prs

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,

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

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!    I guess it would be nice to have the precision though--especially if it doesn't cost much.

Tripleb;

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

prs

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

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! 

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?

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.

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

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.

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

sounds like you did a better and more thorough job than I did.  Good luck

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

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.