The Compatability Of Quick-release Skewers and Horizontal Dropouts

Quick-release skewers can be used with horizontal dropouts when the frame is made of steel. Getting a model with an internal cam is recommended as it provides more clamping power.

If you’re running a fixed-gear bicycle, it’s better to use bolt-on axles because they can resist more torque and make it easier to tension the chain via standard techniques.

Steel Frame = Good Clamping Power

Quick-release skewers were invented by Tullio Campagnolo in 1927 after he experienced extreme frustration when flipping his wheel to switch gears during a brutal winter race.

At the time and until the late 80s, dropouts were forward-facing and horizontal. The quick-release skewers were adequate to hold the rear wheel in place.

Forward-facing Horizontal Dropouts with Shimano Internal Cam Levers

I have a steel road bike from 1987. It has forward-facing dropouts and its original quick-release skewers. To this day, they hold the wheel just fine.

One of the reasons for the superior holding power is the frame material, steel.

Steel frames are not as slippery as aluminum and carbon models. Thus, there’s greater friction between the dropout faces and the quick-release skewer’s retention nuts.

Furthermore, steel is a harder material than aluminum and can face more external stress without showing signs of fatigue. Consequently, the serrations found on the hub’s axle and the quick-release skewers have a harder time removing material from the frame and bite better against it.

Note: Chrome steel is an exception as it is the most slippery surface that a set of dropouts can have.

Wheel Security Is Critical

It’s of utmost importance to have your wheel maximally secure. Otherwise, you’re risking an accident.

It’s unlikely that a wheel will drop out during normal riding even if the skewer isn’t maximally secure because the weight of the rider will prevent that outcome.

However, if a wheel gets loose it can move off-center and jam against the fork/frame or the brake shoes.

If it’s the front wheel, a fall is almost guaranteed. In most cases, the rider will be immediately thrown over the handlebars.

The rear wheel is a bit more forgiving. If it locks unexpectedly at slow to medium speed, it’s very realistic to prevent an accident by remaining calm and carefully bringing the bike to a stop.

Another issue you might face if you run a fixed-gear drivetrain is the loss of braking power via the pedals.

If the rear wheel moves forward, the chain tension will drop and it won’t be possible to effectively lock the wheel via the cranks to slow down the bicycle.

Examine The Hub Too

The quick-release skewer is only one part of the equation. Even if it’s in perfect shape, it may fail to secure the wheel if the hub’s locknut doesn’t have serrations.

Cup and cone hubs (the most common type) have a locknut that keeps the axle secure to the bearings. The locknut is threaded onto the axle and has a serrated outer face helping hub retentions from the inner side of the chainstays.

Locknut Serrations

If the serrations of the locknut are gone, then the quick-release skewer will have difficulty securing the wheel.

The solution is to replace the locknut by taking one from a broken hub or purchasing it separately.

Internal vs. External Cam Lever Skewers

Quick-release Skewer With an Internal Cam

Based on the closing mechanism, quick-release skewers are divided into internal and external cam models.

What’s a cam?

A cam is a rotating piece used for transforming rotary motion into linear motion.

Quick-release skewers have a cam controlled by a lever. When the quick-release lever is closed, the cam pushes the serrations of the quick-release into the dropout and simultaneously pulls the serrated nut on the other side.

When the lever is fully closed both dropouts are pressed into the locknuts of the hub.

This clamping motion secures the hub’s axle into the dropouts of the frame or fork. The axle remains stationary while the hub is rotating around it.

The quick-release skewer doesn’t support anything. [The axle supports the frame.]

Quick-release Skewer With an External Cam

Quick-release levers with external cams have two major weaknesses. First, they can’t match the clamping force produced by a quick release with an internal cam. Second, the cam of the lever is exposed to the elements and subject to corrosion.

Even the cheapest quick-release skewers are good enough for vertical dropouts, but when we’re talking about horizontal dropouts, the best option is to get a quality quick-release skewer with an internal cam.

A quick-release skewer with an external cam can work too, especially if it has a brass rather than a rubber washer, but for safety and best performance, it’s wiser to go with an internal cam.

Quick-release Skewers vs. Track Nuts

Bolt-on axles with track nuts provide the greatest clamping strength. For that reason, they’re consistently used on track bikes and fixies.

The table below sorts wheel securing mechanisms by clamping strength:

Clamping MethodClamping Force*
Quick-release skewer with external camapprox. 550 kgf
Quick-release skewer with internal camapprox. 550-800 kgf**
Axle with Track nutsapprox. 2450 kgf.
*The clamping force is measured in Kilogram-force
**The number depends on the quality of the skewer

Summary: What You Need To Know

Quick-release skewers can be used on horizontal dropouts when:

  • The skewers have an internal cam.
  • Aluminum frames are too soft and the serrations on the quick-release skewers often remove material and fail to form the needed indentations for maximum friction and grip.
  • If you have a track bike or a fixie, it’s recommended to stick with bolt-on axles and serrated track nuts as they provide the greatest clamping force and can therefore withstand the pulling force of the chain when braking via the pedals.

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