Speedometer weirdness
 

Greetings -

Wondering if anyone else has experienced this - speedometer readings bounce around a bit. Seems OK up to about 40 mph but after that it's no longer steady. For instance, I can be doing what I know is 75 mph or so but the speedometer will display like this: 60, 64, 60, 62, etc. It's always lower than actual speed and changes about every second. Hoping someone can shed some light. Oh, it's a 2005 SV650S. Thanks for any input.

Re: Speedometer weirdness
 

Check the speedo ring on the front wheel. They get damaged / wear.

Re: Speedometer weirdness
 

It might be corrosion on any of the connectors between the sensor and dash - it sounds a bit like electrical "noise". You would need to locate the connectors, disconnect them and spray with a contact cleaner or ACF50.

Is your forum name your email address? You might want to change that or you may get a whole lot of new friends trying to sell you stuff. :rolleyes:

Re: Speedometer weirdness
 

The speedo rotor sometimes chews itself to pieces.

Re: Speedometer weirdness
 

Mine was like that. Quite fragile. I assumed it was me being cack-handed when refitting the front wheel.

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Re: Speedometer weirdness
 

Thanks to all for responses. One mentioned connectors, which makes me ask another question - how does data get transmitted from the speedo ring to the speedometer? I haven't had a chance to look at the bike but I have been looking at the service manual. It doesn't show any kind of wire or cable to do this and I've never seen anything like that on the bike so how does the speedo get its info? Thanks again for input.

Re: Speedometer weirdness
 

It's hard to find a picture but here is the speedo parts diagram:
https://www.fowlersparts.co.uk/parts...r-sv650ak7uak7

Part #22 is the speedo sensor and it sits on the left side of the front forks.
This picture, for an "N" model unfortunately, shows the speedo sensor within the headlamp and a (basic) method of testing the sensor.
https://www.manualslib.com/manual/80...age=408#manual

The bit that breaks that people have referred to looks like this:
https://www.manualslib.com/manual/80...age=289#manual

Showing installation:
https://www.manualslib.com/manual/80...age=292#manual

The part changed over the years from a 4 segment to an 8 (?) segment rotor - not sure when it changed (Bibio knows).

Re: Speedometer weirdness
 

Have you had the front wheel off recently? It has to be refitted very carefully or it breaks the rotor which can cause exactly the symptoms you describe.

Re: Speedometer weirdness
 

Once again, thanks to all who responded for some very helpful info. The front wheel was off recently when the shop replaced the front tire. I think I will get a new speed sensor and have them replace the old one.

Re: Speedometer weirdness
 

OK, it took a while to get the speed sensor and then get it installed. It got installed today but it only fixed half of the problem. The good news - speedo display is now smooth, doesn't jump around like it used to. The bad news - speedo now always displays about half of the value it should. Seems pretty consistent - if I'm doing what I know is about 50 mph it displays 25; if I'm doing what I know is 80 it displays 40. Anyone?