Absolutely this is not normal. A torsion spring should always be straight and not curled when it is fully loaded. The first thing you need to know about torsion springs is that there is always a left or right hand wound springs this is kind of confusing but it is marked by color of paint at the direct end of the spring cone where you wind it. It will either be red or black or red. Anytime there is red paint sprayed on a part of a garage door usually it means danger do not remove this screw or bolt or it means red is left and if it is painted black then black means right side of the garage door. These things are important if you ever try to fix or adjust your garage door on your own without a professional. If you have a bolt or a screw on a garage door and it is painted red never mess with it – This will cause major problems, major injury or in the worst case scenario, death. Most garage door manufacturers but not all will paint the screws or bolts that tie the bottom bracket at the bottom left hand or right hand side of your door. Now as far as the torsion springs go when they move along on the torsion pole there are only two things to cause this one is that the spring may be not put in the right position in other words if your right hand spring is curling up then somebody may have put a left hand spring where the right hand spring should be.
spring did not have the ability to slide along the pole
The other reason for this effect would be that when the spring was wound up it did not have the ability to slide along the pole as it was wounded. A spring when it is wound is going to be about 2 inches longer than when it is unwound. For example if this spring that is curling up is on the right hand side of the garage door in the right side cone should be painted black do not confuse the right or left hand color with the color of the spring that is actually spray painted on the actual wire part of the spring. This color will determine the wire size and gauge of the spring that you have. It can be any color from white, yellow, red, gold, green, blue or Brown. If the spring is correct as being on the left or right hand side due to color code and it is still curling up then usually this means that when the spring was wound and could not travel along the pole correctly. This is usually caused by a distortion to the torsion tube in other words there is either too much of a dent in the tube from tightening down the lockdown screws and it has distorted so much that the spring does not move freely across the torsion tube poll. If somebody was to wind the spring and it does not move along the tube when they wanted it then this will have the effect of curling up the spring. To correct this problem most of the time you can use a metal file and file down the area where the spring does not move across the pole if this does not work then replacing the torsion tube is the only way to correctly get the spring to wind. In most cases you will have to call a professional garage door technician to deal with this problem if you have no experience with garage door torsion springs than you need to leave it alone and leave it to the professionals.