Speedometer inacurate

[Blutoy]

Hello, I recently purchased my first bike; it is an 82 vision. I purchased it from a board member and after doing a few searches I have one question.

The speedometer works fine, but it is not very accurate. I'd say it is off by about 35%  (Speedo says I'm doing 55, but it is closer to 85). I had a friend on another bike pace me and the problem is at all speeds. Any one have any suggestions for this? Thanks in advance.

[h2olawyer]

Welcome, Blutoy -

Congrats on getting - at least what we mostly think here - a great & interesting bike!  The Vision does have several annoying quirks.  Weak charging systems, finicky carbs, headshake, tank rust, electrical gremlins, etc.

The speedometer problem on 82s is very common.  They all read somewhat slower than the actual speed you're travelling.  The degree of error tends to vary among the bikes, though.  As far as I know, this is just a problem that you will learn to live with.  

One possible solution:  While pacing a vehicle with a speedometer known to be accurate, make a note of what your speedo reads.  You can then use small pieces of pinstriping tape to mark the most common speed limits in your area.  Just stick the tape @ the appropriate spot on the outside of the speedo cover.  There may be a way to have a speedo shop calibrate it but I don't know if anyone's looked into that option as yet.

H2O

[JoshNeff]

I'm going to have to second this problem, because I was doing 30mph in 3rd gear aroudn 7k.  In a 30mph zone, and I got pulled over because apparently, i was going WAY to fast.  

?

I took it out and should of been doing 55, it said 40.  I've just riden in it town now and mostly that's just keeping up with traffic and not paying attention to speed so much as making sure cars watch out for me and all that... you can also pick up some GPS systems for fairly cheap that could tell you speed, as well as a ton of other fun functions.   Cheaper then having it "fixed" most likely, but a higher cool factor then tape on the gauge

[coyote_killer]

My 82 speedo is off too...When mine says I'm doing 60 I'm really doing 68 and when it says 80 i'm really doing 90 because the faster I go the farther its off....I bought this bike new and I just figured out that the speedo was slow a couple of weeks ago thanx to this program....   http://www.virtualengine2000.com/Download.htm      .....I plan on memorizing a few common speeds and RPM's and then just go by the tach....

And for all these years I thought everyone else was afraid to ride....

[h2olawyer]

Just another thought.  Some folks here have been designing some new speedo face graphics.  There may be a way to change the design somewhat so your speeds are more accurately represented on the new graphics.

Coyote_killer is right -  the faster you go, the greater the error seems to be.

H2O

[Lucky]

Blake & others also add bicycle computers to their guages, these are highly accurate, cheap & easy to install

[silicon_toad2000]

The problem is that the magnetic disc on the back of the spedo looses its magnetism over time, it happens in all vehicles, just some more than others depending on the magnetic properties of the disc.
Here we have a few places that recalibrate spedo's. You should be able to find some near you.
The -plces here we can either deliver the spedo and they will set it back to factory or deliver the vehicle and they will calibrate. (havent had a speeding ticket since i got the spedo in the datsun calibrated, not sure why)

[George R. Young]

If I remember correctly, in 5th gear 5250 RPM corresponds to 60 mph.

[Brian Moffet]

I think this is only on the 82's, I believe the 83 had different gearing.  I believe the 83's had a slightly higher 5th gear.

Unfortunately, I'm not near my references.

Brian

[Blutoy]

Thanks for the help, I always seem to have vehicles that have slow speedo's so this is nothing new to me. I was just checking if there was a simple solution.

So far I love my bike, this board is great to be on; I will lurk more than post but the information is invaluable, thanks to all.

[Rick G]

Mine was reading  55 seconds at 60 mph , it should be 60 seconds, 70 mph was actually 82 and 85 was about 108.  

I solved the problem by installing a Canadian 220 kph/140 mph speedo . For some reason the US 140 and the canadian 220  are far more accurate. I ahve no information on the European speedos.
Some one should try getting one recalibrated.

[jasonm.]

My '82 reads similar to RickG. I have a digital bike speedo. Works great... My '83 is only about 2-3mph low at the higher speeds.

[PeteN]

You also have to take into account the tire sizes mounted to the bike.  An oversize front tire will increase the too low reading on the speedo.   An different size rear tire will change the tach reading at any speed.  My speedo is a little closer now that I've gone from a 110 front tire to a 100.  But it still reads low.

[Superfly]

Who makes a good speedo for this bike?

[Rick G]

JC Whitney sells a pair instraments  that are reasonable and look like they would fit . You will have to get  a suitable temp guage too.
I had thought of a set of Virago guages  as well, some look pretty good. but again you would need to look into a suitable temp guage.

[jasonm.]

I use a Sigma Sport BC800. This model can be calibrated for 2 different bikes. I have 2 Visions so for me it Works great. Speedo was $25 and the extended wiring was $10. But you really can make your own extension.