Do You Know How Zippers Work?!

If you’ve spent any time in endurance sports, you’ve probably had at least one battle with a zipper.

You’re halfway through a ride, overheating, trying to unzip your jersey with one hand while staying aero… and the zipper refuses to move.

Sometimes it slides perfectly.

Other times it feels completely stuck.

Most of the time, it’s not actually a zipper issue.

It’s operator error.

And honestly, once you understand how performance zippers work, the design makes a lot of sense for endurance sports.

Most Triathlon and Cycling Zippers Are Designed to Lock

Many performance jerseys, tri suits, and swim skins use what’s called a locking zipper.

The mechanism is simple:

• Tab down = locked

• Tab up = unlocked

  
  

Inside the zipper slider is a tiny locking pin.

When the pull tab lays flat—typically pointed downward—that pin presses into the zipper teeth and prevents movement.

Lift the tab upward, and the pin disengages, allowing the zipper to move smoothly.

That’s it.

Simple system. Extremely effective.

And once you know it, you suddenly realize why your zipper sometimes feels “stuck” during training.

It’s usually working exactly as intended.

Why Locking Zippers Matter in Endurance Sports

This might seem like a tiny detail, but small details matter a lot in triathlon.

In training and racing, you want control over everything you reasonably can.

Including your zipper.

In the Swim

When you’re swimming, you absolutely want your swim skin zipped up and secure.

The last thing you want is water catching your suit because the zipper slowly worked its way down during the race.

Then the second you exit the water?

You want that same zipper opening immediately and smoothly during transition.

Knowing how the locking mechanism works can make getting out of your swim skin significantly faster.

On the Bike: Aero Matters

On the bike, most athletes want their kit zipped and stable.

A zipper that slowly creeps downward during a ride is annoying at best and disruptive at worst.

Locking zippers prevent unwanted movement while riding, especially when you’re in an aero position for long stretches.

And when you do want to cool down mid-ride?

Understanding how to unlock the zipper properly makes one-handed adjustments much easier.

No awkward yanking required.

During the Run

Once you hit the run, comfort becomes even more important.

Maybe conditions heat up.

Maybe you want more airflow.

Maybe you simply race better partially unzipped.

The good news is that modern race rules are generally more forgiving about zipper position on the run than they once were.

But again, the key is control.

A properly functioning zipper stays where you want it.

Ready for Your Mind to Be Blown?

Go grab a swim skin or cycling jersey right now.

(Our NVDM team kits work perfectly for this test.)

1. Zip it all the way up.

2. Flip the zipper tab downward into the locked position.

3. Pull the neck apart.

   
   

Notice something?

It stays closed.

Now flip the tab upward and try again.

The zipper slides open immediately.

That’s the locking mechanism working exactly as designed.

Once you know this trick, suddenly:

• Getting out of your swim skin becomes easier

• Mid-ride jersey adjustments become smoother

• One-handed zipper control becomes way less frustrating

  
  

Tiny detail. Big difference.

The Best Gear Is the Gear You Don’t Notice

One of the funny things about endurance equipment is that the best-designed gear often disappears into the background.

You only notice it when something goes wrong.

A good locking zipper is one of those features.

Simple.

Functional.

Reliable.

And when you’re deep into a long ride, hard workout, or race situation, those small details matter more than most athletes realize.

Because in endurance sports, efficiency is rarely about one giant breakthrough.

It’s usually about stacking hundreds of small advantages.

Even the ones hiding in your zipper.

Endurance performance is built on mastering the small details.

At NVDM Coaching, we help athletes optimize everything from training structure to race-day execution so nothing gets left to chance.

Train smarter. Race smoother. Perform better. Apply for coaching today!