From the speedo itself down to the wheel; the entire cable and sheath. Sounds like yours may be dry, and the cable is rubbing against the sheath, causing the "jump' you are seeing. I use wheel bearing grease, but you could also use silicone spray, like the guy in the video, or chain lube. If you use grease, run the cable through the sheath, rotating it as you go, to coat the inside of the sheath with grease. Then remove the cable and wipe off any excess grease and install.