A longshot.. but have you checked the big plug that goes into the speedo housing?

Another longshot: when putting in the raceratb corrected face plates you have to pop off the needle. It fits on using friction. Is it possible the needle is loose? (I can't see how this could match your symptoms...)

..Tom

 

... As soon as I hit the throttle the speedometer drops to zero.
...

Could there be too little slack in the wire so it is getting pulled when accelerating?

..Tom

 

Apperntly I zip-tied something to the speed sensor wire (oops) and kinked it. They replaced and re-routed the wire so no zip-ties were in the way and now it works.

In the process they also managed to get my throttle cable to stick on the tab coming in front of the radiator so I had to manually adjust the throttle back to idle. I took it back after a very short ride and they found/fixed that too.

Long story short....Bike is ready to ride again!

 

My digital speedo display is just today doing this too. Just sitting on zero or bizarrely fluctuating between a couple of speeds. All the zip ties for heated grips an a USB power and voltage indicator are mine. I noticed the issue right after a hard acceleration. And then came and went a bit but mostly zero. The pinched speedo sensor cable seems a very likely culprit. I literally have my service manual coming via ups today, just wild timing, but if anyone has a description or pic of the speedo sensor cable for a 2013 vstrom I would aoppreciate it. Will check to see if I am strangling it somwhere. If a kink has set in I have likely killed mine too. Will let you know. Thanks for posting!!!