Heavy drag. Sanding sound in rear. Metal on metal. Electrical problem I think

[Hud]

I have a periodic heavy raspiness coming from the rear end which causes heavy drag sounds like metal on metal and it's a sanding sound sometimes you can hardly push the pedals any ideas

 

[Bruce Arnold]

Motor problem? Doesn't sound electrical to me. My next guess is, check the brakes. If they're not opening properly, you might get something like this.