What are Quick Release Axles?

Quick-release axles are the most common wheel attachment system for most mountain bikes. They allow you to remove and replace the wheels quickly and without any tools.

Now all Rurui Bikes are using quick-release axles to replace the solid axles in the first batch of XT9 and XT10. Let’s take a quick look at the quick-release axle and the different with the solid axle.

A Bit of Quick Release History

While racing through freezing weather in the Dolomites in November of 1927, Italian cyclist Tullio Campagnolo was slowed down by a stuck wingnut on his axle. He needed to remove the wingnut so he could remove his wheel to change gears. (At that time, bicycles had a sprocket on either side of the rear wheel. In order to change gears, you would remove the wheel and flip it around.) The misbehaving wingnut on Tullio’s bike cost him precious time which ended up costing him the race.

bicycle racing

This experience inspired Tullio to develop a quick-release wheel locking mechanism. This invention allowed cyclists to remove and replace their wheels in seconds. The quick-release axle was patented in 1930 and became the standard for over 90 years. Tullio went on to patent numerous cycling and non-cycling inventions and founded the cycling company Campagnolo.

What are Quick Release Axles?

Quick-release axles are the standard wheel attachment system used on most bikes. They allow you to remove and replace the wheels quickly and without any tools. You don’t even need to remove the axle from the hub.

quick release axles

A quick release axle system is composed of a thin metal skewer that runs through the hubs. The skewer is held in place by an acorn nut on one side and a quick release cam lever on the other. Two small springs sit on either side of the hub.

The dropouts on a quick release frame and fork have u-shaped slots. The wheel secures to the bike by slotting the skewer into the u-shaped dropouts, slightly tightening the acorn nut, and clamping the quick release lever closed. A cam mechanism tensions the axle and holds the wheel in place with friction. The quick release axle stays in the hub when you remove the wheel.

Most quick release axes measure 5 mm or 9 mm in diameter. Various lengths are available to fit different hub spacing.

What are Bolt On Skewers?

Bolt-on skewers (solid-axles) work exactly the same as quick release skewers except they tighten with a bolt instead of a cam lever. They have the same diameter as QR. The bolt-on design allows you to tighten the axle tighter than you can with just your hand. Using a wrench or hex key to tighten the axle gives you more mechanical advantage.

 solid axles

Bolt on axles offer a few advantages over standard quick release. First, they make it less likely for your wheel to come off simply because they hold the wheel tighter. For this reason, many quick release disc brake bikes come with bolt-on skewers. They make it much less likely for the axle to loosen or the wheel to eject during hard braking.

Another benefit of bolt-on skewers is that they make it slightly harder for a criminal to steel your wheels. They would need a wrench to remove the bolt. They can’t just use their hand like they can with a lever. The bolt also looks a bit sleeker than the lever.

There are some disadvantages to bolt-on axles. First, you’ll have to carry a tool to take your wheels off. This adds a bit of weight to your tool kit. It also takes a few seconds longer to remove and replace the wheels. This can be annoying if you take your wheel with you when you park your bike to avoid theft.

Final Thoughts about Solid Axles, Quick Release, and Thru Axles

Thru axles are becoming increasingly popular these days. Over the past 10 years, they have pretty much become the standard on mountain bikes.

Some riders believe the thru axles provide better performance under stress and improve control. While others feel that thru axles are just a way for the industry to sell more bikes and components. There is probably some truth to this. The advantages they offer aren’t really noticeable for the average recreational cyclist.

Some riders persist on solid axles because quick-release skewers look weak and will bent/break easily. And others contradict it as a myth that violates the materials science theory. The solid axles are stronger than QR axles only when the skewer does not install into the axle.

So, what is the axle type of your current bike? Will you consider upgrading it to a thru-axle?


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