How Each Spring System Actually Works
Torsion springs sit on a steel shaft above the door opening, mounted to a center bracket and wound with tension. When the door closes, the springs wind up and store energy. When it opens, that energy unwinds and lifts the weight. The force stays even because the spring rotates on a fixed axis.
Extension springs run parallel to the horizontal tracks on each side of the door. They stretch as the door closes and contract to pull it open. Each spring carries half the load. The force curve is not linear — it pulls hardest at the bottom of travel and drops off as the door rises.
That difference in force delivery changes everything downstream: cycle life, safety, headroom needed, and what fails first.
Lifespan and Cycle Ratings
A standard torsion spring rates 10,000 cycles — one cycle is a full open and close. At four cycles a day, that is roughly seven years. High-cycle torsion springs (25,000 to 50,000 cycles) are common on commercial doors and available for residential shafts that have the room.
Extension springs typically rate 5,000 to 10,000 cycles. The stretching action fatigues the wire faster than torsion’s twisting action. In a damp coastal climate, the exposed coils on extension springs also corrode quicker because they lack the protective powder coat that many torsion springs carry.
If you open your door six times a day — two cars, kids coming and going — a 10,000-cycle spring lasts four and a half years. A 25,000-cycle torsion spring lasts eleven. The math is that simple.
Safety When Things Break
A torsion spring fails by snapping on the shaft. The energy releases in a loud bang. The broken ends stay on the shaft, contained by the winding cones and center bracket. It scares you. It rarely injures you.
An extension spring fails by whipping. The stored energy flings the broken coil across the garage. Without a safety cable threaded through the center of each spring and anchored at both ends, the broken piece becomes a projectile. I have seen a broken extension spring punch through drywall on the opposite wall. With safety cables, the spring stays restrained. Without them, it is a hazard every time the door moves.
If your extension springs do not have safety cables, install them today. It is a ten-minute job with aircraft cable and two cable clamps per side.
Headroom and Sideroom Requirements
Torsion needs headroom — typically 12 to 18 inches above the door opening for the shaft, drums, and spring assembly. Low-headroom kits exist (as little as 4.5 inches) but they use a different drum geometry and cost more. You also need a few inches of sideroom on each side for the bearing plates.
Extension springs need almost no headroom. They live in the horizontal track space. They do need sideroom — about 4 to 6 inches on each side — for the pulley forks and cable runs. In a tight garage where the door opening brushes the side wall, extension may be the only fit without reframing.
New Westminster’s Queens Park homes often have 6-foot-6 headroom and non-standard opening widths. Torsion fits, but the spring sizing is custom every time. Surrey’s Newton garages from the 1970s often have standard 7-foot headroom and 8-foot-wide single doors — either system works, but torsion lasts longer on the same hardware.
Cost Drivers, Not Prices
Torsion parts cost more upfront: the spring (or pair), shaft, drums, bearing plates, and center bracket. Labor is higher because winding torsion springs requires winding bars and a specific procedure. Done wrong, the spring unwinds violently.
Extension parts cost less: two springs, four pulleys, two safety cables, and the track hardware. Labor is faster — no winding, just stretch and hook.
But the total cost over ten years favors torsion. One torsion spring change at 10,000 cycles versus two or three extension spring changes in the same period. Add the safety cable retrofit if it was skipped originally. The cheaper install becomes the expensive one if you stay in the house.
How to Tell Which You Have
Look above the door. A steel shaft with a spring (or two) wound tight on it, center bracket anchored to the header — that is torsion.
Look beside the horizontal tracks. Long springs stretching back from the door, pulleys at each end, cables running over the pulleys to the bottom brackets — that is extension.
Hybrid systems exist. Some older doors use a rear-mounted torsion spring (Wayne-Dalton TorqueMaster) inside a tube. It looks like extension from the outside but winds like torsion. If the spring is hidden inside a tube, do not guess. Call a tech.
What a Technician Checks Before Recommending
Door weight. Sectional steel doors weigh 130 to 250 pounds depending on insulation, gauge, and width. Wood doors run heavier. The spring must counterbalance within 5 to 10 pounds. Over-sprung doors fly up. Under-sprung doors crash down.
Track radius. Standard 12-inch radius tracks work with both systems. Low-headroom 6-inch radius tracks change the drum size on torsion and the pulley geometry on extension. Mixing parts across radii causes binding.
Cycle history. If the homeowner does not know the spring age, the tech checks the winding cone paint marks (torsion) or measures the relaxed spring length (extension) against the door height. A stretched extension spring that does not fully relax when the door is open is already fatigued.
Cable condition. Frayed cables on extension systems often mean the pulley bearings are seized, adding drag that overloaded the spring. On torsion, cable wear at the drum groove means the drum is misaligned or the shaft is bent.
The DIY Line — And Why It Exists
Extension springs: a competent homeowner with two winding bars (not screwdrivers), a ladder, and a helper can swap them. The springs are not under tension when the door is fully open and clamped. You unhook, measure, order exact replacements, reverse the steps. Safety cables go on at the same time.
Torsion springs: do not. The spring is under full tension when the door is closed. Winding and unwinding requires steel winding bars inserted into the winding cone holes. If a bar slips, or the cone cracks, or you lose count of turns, the spring releases its energy into your face, hands, or arms. Broken bones, lacerations, and fatalities happen every year. This is not a “be careful” job. It is a “wrong tool, wrong training, wrong outcome” job.
If you have torsion and the spring is broken, the door will not open. Do not try to force it with the opener. Do not pull the emergency release and try to lift it manually — a 200-pound door with no counterbalance will crush fingers or trap you under it. Call a tech.
Preventing the Next Failure
Lubricate the coils (not the track) twice a year with a non-silicone garage door lubricant. Silicone dries to a powder that accelerates wear. White lithium or PTFE spray works.
Check balance once a season. Disconnect the opener. Lift the door halfway. Let go. It should stay. If it drifts down or shoots up, the spring is out of adjustment or the wrong rate. Adjustment on torsion means adding or removing quarter-turns. On extension, it means moving the S-hook to a different hole on the track hanger. Both change the preload. Do not adjust torsion yourself.
Replace both springs (or all four on extension) at the same time. The mate has the same cycles. It will break within months. Mismatched spring rates unbalance the door and burn out the opener gear.
In coastal Metro Vancouver, wipe salt residue off springs and hardware after winter storms. Corrosion pits the wire and starts the crack that becomes the break.
Quick Comparison Table
| Factor | Torsion | Extension | |——–|———|———–| | Typical cycle life | 10,000–50,000 | 5,000–10,000 | | Headroom needed | 12–18 in (standard) | 4–6 in | | Sideroom needed | 3–6 in per side | 4–6 in per side | | Break containment | Shaft retains pieces | Requires safety cables | | DIY replacement | No | Yes, with caution | | Cost per cycle (10 yr) | Lower | Higher | | Best for | Standard to high-headroom garages | Low-headroom, tight sideroom |
Choose the right spring system for your garage door
If you are buying springs, weigh the door first. Bathroom scale under the center, disconnect the opener, lower the door onto the scale. That number, plus the door height, track radius, and drum size (torsion) or pulley diameter (extension), determines the exact spring. Guessing by “it looks like the old one” is how you get the wrong rate.
If you have torsion and it is broken, or you are not sure which system you have, call 778-873-7282. We will identify it, weigh the door, and install the correct spring with the right cycle rating for how you actually use the garage.