i was riding in town about 35-40 km/h....and all of a sudden an old lady crossed the street....i had an extra passenger...and was about 8 feets away from her.....fortunetly had the time to brake.... after that, i noticed that my speedo needle was going up till 30-40 km/h then started going down to 0 and back up again.....very unstable i was jumping all around... once back home, i unscrewed my cable from both sides, and checked it, no visual damage was made, i also pulled the inside cable out, it was fine, and was able to spin it from one end, and it did the same from the top.... i put it back in again, thought maybe something was loose....the needle worked fine, until i drove on a road bump (have a lot of these here in lebanon due to people driving like crazy) then it started doing the same thing again.... i unplugged the top (speedo plug), and started moving the bike forward, as i had my fingers on the cable, and it was spinning....then i plugged the top to the speedo, unplugged the buttom near the tire, and spinned it with my hands, the speedo needle moved too....i'm very confused what's going on here... by the way, 2 days ago, i had my front tire off, (had to replace my fork seals rubber and changed oil too)... i really don't know how to troubleshoot this issue, any help would be much appreciated !!
Sounds like a problem with the drive gear at the front wheel, perhaps slipping. Pull the front wheel off and check it is all OK..
Finally it works!!! turned out to be the drive gear as you said, when i was working on my front forks, i didn't tightened the wheel enough ! so the drive gear moved a bit out of it's place, that's why it wasen't working anymore !! thank you !
Great news... <!-- s:Biker1: --><img src="{SMILIES_PATH}/th_Biker_1.gif" alt=":Biker1:" title="biker_1" /><!-- s:Biker1: -->
