What are the disadvantages of a thru axle?
Thru axles have become the standard on many modern bicycles, from sleek road bikes to rugged mountain bikes. They offer a stiffer connection between the wheel and the frame, leading to better handling and braking. However, like any piece of technology, they aren't without their drawbacks. For the average American cyclist, understanding these disadvantages can help in making informed decisions about bike maintenance, upgrades, and even bike selection.
Complexity and Maintenance
One of the primary disadvantages of thru axles is their increased complexity compared to traditional quick-release (QR) skewers. While QR skewers are remarkably simple – a lever that opens a cam mechanism to loosen and tighten – thru axles involve a threaded bolt that screws directly into the frame or fork. This means:
- Requires Tools: Unlike QR skewers that can be tightened or loosened by hand, thru axles almost always require an Allen wrench (hex key) to remove or install a wheel. This means carrying tools on rides, which can be an inconvenience if you're used to the tool-free operation of QR.
- Thread Stripping Risk: Because thru axles are threaded, there's a risk of stripping the threads on either the axle itself or the corresponding threads in the frame or fork if they are overtightened, cross-threaded, or if dirt and debris get into the threads. This can lead to costly repairs.
- Specific Torque Settings: For optimal performance and to avoid damage, thru axles are often recommended to be tightened to a specific torque value. This usually requires a torque wrench, an additional tool that many casual riders may not own or be familiar with using.
Weight
While not a massive difference, thru axles are generally heavier than their quick-release counterparts. The solid metal rod of a thru axle, along with its threading mechanism, typically weighs more than a hollow QR skewer. For competitive cyclists where every gram counts, this can be a consideration. However, for the vast majority of recreational riders, this added weight is negligible and the benefits of stiffness and security often outweigh this minor disadvantage.
Compatibility and Standardization Issues
This is a significant pain point for many cyclists. While thru axles offer a more robust connection, the world of thru axles isn't as standardized as one might hope. There are various:
- Diameters: Common diameters include 12mm and 15mm for front wheels, and 12mm for rear wheels, with different widths.
- Lengths: The length of the thru axle needed depends on the specific frame and fork dropout width.
- Thread Pitches: The distance between the threads on the axle can vary.
This lack of universal standardization means that if you lose or break a thru axle, you can't just grab any old one from your LBS (Local Bike Shop). You need to know the exact specifications of your bike's thru axle to get a replacement. Traveling with multiple bikes, or lending a wheel to a friend, can become complicated if their thru axle dimensions don't match yours.
Cost of Replacement Parts
Due to the specialized nature and varying standards, replacement thru axles can be more expensive than generic quick-release skewers. If you damage an axle, you'll likely have to purchase a specific replacement from the manufacturer of your bike or fork, or a specialized aftermarket supplier, which can add up.
Wheel Removal and Installation Nuances
While the process of removing a wheel with a thru axle is straightforward once you have the correct tool, it can be a point of frustration for those accustomed to quick-release levers. The need to unscrew the entire axle, and then carefully thread it back in, can feel slower and more involved. Furthermore, some bikes have internal cable routing or hydraulic brake hoses that can make wheel removal and reinstallation slightly more fiddly with a thru axle.
When are Thru Axles a Problem?
Thru axles are most often a disadvantage in situations where:
- You need to fix a flat quickly on the trail: Not having the right tool readily available can turn a quick tube change into a more time-consuming ordeal.
- You need to transport your bike frequently: Constantly removing and reinstalling wheels with a thru axle can become tedious.
- You are sharing or lending wheels: The strict compatibility requirements can make this difficult.
For the vast majority of riders who keep their wheels on their bikes and only remove them for maintenance or transport, the disadvantages are often outweighed by the benefits. However, understanding these potential downsides is crucial for proper bike care and a smoother cycling experience.
Frequently Asked Questions (FAQ)
How do I know if I have a thru axle or a quick release?
Look at your wheel's hub. If you see a lever sticking out that you can flip open to release the wheel, that's a quick release. If you see a bolt head (usually requiring an Allen wrench) that you need to unscrew to remove the wheel, that's a thru axle.
Why do some bikes still use quick releases if thru axles are better?
While thru axles offer advantages, quick releases are simpler, lighter, and faster to operate for wheel removal and installation, especially for casual riders or those who frequently need to take their wheels off. For entry-level bikes or certain types of cycling where extreme stiffness isn't paramount, QR can still be a practical choice.
What happens if I lose my thru axle?
If you lose a thru axle, you'll need to identify the exact specifications (diameter, length, thread pitch) of your bike's axle to purchase a correct replacement. This information is often found on the axle itself or can be obtained from your bike manufacturer's website or manual.
Can I convert my quick release bike to thru axles?
Generally, no. Converting a bike from quick release to thru axles is not a simple swap. It requires compatible frame and fork dropouts, and often new wheels with thru-axle compatible hubs. It's usually a significant upgrade that involves replacing major components.
