Identifying the correct Birtley spring

Birtley canopy doors use a single overhead torsion spring mounted on a shaft across the top of the door frame. The spring specification is determined by the door width and the weight of the door panel. For a standard door width, the replacement spring is specified by:

• Door width: Measure the door opening width (typically 7ft, 7.5ft or 8ft for standard single-width doors)
• Wire diameter: Measure the wire thickness of the existing (broken) spring with callipers if possible
• Coil diameter and coil count: These can be measured from the broken spring or estimated from the door weight

If the broken spring cannot be measured, provide the door width and the door panel material (steel, GRP or timber) when contacting Northwest Garage Door Spares. We can recommend the correct spring specification for your door.

Replacing the Birtley canopy overhead spring

1. Open the door fully and clamp it securely in the open position on the track. This releases tension from the spring and cables, making the door safe to work on.
2. Photograph the spring shaft arrangement, the cone positions and the cable routing on both sides before starting.
3. The spring sits on a shaft spanning the door frame top, held at each end by bearing plates. The spring is tensioned by winding it onto the shaft with winding bars through the holes in the winding cone at one or both ends.
4. Release the spring tension carefully using winding bars, working in small increments of a quarter turn at a time. Never release the winding bars suddenly or work without winding bars in both holes simultaneously.
5. Once fully unwound, the spring can be slid off the shaft. The shaft may need to be disassembled at one bearing plate end to allow the spring to be removed.
6. Fit the new spring onto the shaft in the same position and orientation as the original. Wind tension into the spring using the winding bars to the same number of turns as the original (typically 7 to 9 quarter turns for a standard door, but this varies by door weight).
7. Lower the door and test the balance at the halfway point before using the door.