Does my garage door need one spring or two?
Weight decides, not preference. Single doors under roughly 120 pounds run fine on one torsion spring. Anything heavier, which includes virtually every 16-foot double door and most insulated singles, should carry two. A pair splits the workload, lifts evenly, and leaves a working spring to slow the door if its twin fails.
What each setup looks like in the wild
Drive through any OKC neighborhood and you will find three configurations. Older or budget single-car doors, common in Warr Acres and The Village, run one torsion spring centered on the shaft. Most modern double doors carry two springs meeting at the center bearing plate, one wound left and one wound right. And builder-grade homes from certain years, especially early-2000s developments in Moore and south OKC, sometimes have a single oversized spring on a 16-foot door because it shaved a little off construction cost.
That last group is where the trouble lives. The door works, but one spring is absorbing every cycle of fatigue alone, and when it breaks there is nothing holding back 150-plus pounds of door.
Why pairs win on heavier doors
| One spring | Two springs | |
|---|---|---|
| Load per spring | 100% | 50% each |
| Lift symmetry | Torque enters at one point | Balanced across the shaft |
| If a spring breaks | Door is dead weight | Survivor slows the fall |
| Hardware wear | More stress on center bearing | Distributed |
| Replacement pricing | Driven by spring size and cycle rating | Modestly more for the pair, sized to share the load |
The safety line in that table deserves emphasis. When a lone spring lets go with the door overhead, the opener is suddenly holding everything, and openers are lifters, not brakes. With a pair, the surviving spring keeps the door controllable, which protects whatever, or whoever, is under it. It is the same philosophy behind safety cables on extension springs: assume steel fails eventually and design for that day.
Converting from one spring to two
If your double door runs a single spring, converting to a pair during your next spring replacement is straightforward. The shaft, drums, and cables usually stay; we add a second spring, size both to share the door's weight, and rebalance. In the OKC market the conversion adds only modestly to a like-for-like single-spring swap, and it roughly doubles the fatigue life of the system since each spring now works at half stress. For households running 6 or more cycles a day, pairing that with 25,000-cycle springs is the set-it-and-forget-it option; the math is in our cycle rating answer.
When one spring is genuinely correct
No need to oversell two springs where one belongs. An 8x7 non-insulated steel door weighing 80 to 100 pounds is well served by a single properly sized spring, and adding a second means two smaller springs doing the same total work for more parts cost. The judgment call is weight, headroom, and usage, which is exactly what a tech settles in the first ten minutes of a free estimate. If you are unsure what is on your shaft now, snap a photo and text or send it over; identifying a setup takes us seconds.
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Related Questions
What does a 10,000-cycle rating on garage door springs actually mean?+
A cycle is one complete open and close, and the rating estimates how many the spring steel can take before fatigue failure. Four cycles a day exhausts 10,000 in about 7 years. High-cycle springs use thicker, longer coil to multiply that life. Read the full answer →
Can I convert my extension springs to a torsion spring system?+
In most cases yes, provided the header has 10 to 12 inches of clearance for the shaft and springs. Conversions are a moderate, worthwhile job around OKC and buy smoother travel, better balance, and a big safety upgrade over aging stretch springs. Read the full answer →
Why are my garage door cables loose and hanging slack?+
Slack cables usually mean the spring tension that keeps them taut is gone, most often from a broken spring. Other causes include a cable that jumped its drum or a door that was forced down onto an obstruction. Stop using the door until it is inspected. Read the full answer →
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