This post contains nine tips that can help you get a stuck axle out so that you can replace the wheel/tire or fix a flat.
Breaker Bar + Quality Allen Socket
Sometimes the only problem is the lack of mechanical advantage.
Additional leverage can easily be obtained by purchasing a breaker bar (essentially a long socket wrench) and a 3/8th Allen socket (the usual size of thru-axle bolts).
The longer bar will multiply the effort a multitude of times. Make sure that the Allen sock is made of quality steel or else it will be easily stripped.
Penetration Oil + Tapping
A classic method would be to soak the axle’s parts sticking out with penetration oil such as PB Blaster and then lightly tap the axle with a rubber mallet or an equivalent.
Another option is to put an Allen key into the axle’s head and tap it even harder.
This method is fairly cheap and has a decent success rate when the axle isn’t brutally stuck.
DOT Brake Fluid + Blow Dryer
One method of releasing a stuck thru-axle involves the usage of DOT brake fluid and a blow dryer. The procedure is as follows:
- Put DOT brake fluid on the threaded frame or fork dropout. Let the fluid sit for 15 minutes.
- Heat the threaded side with a blow dryer (don’t use an open flame). DOT brake fluid is flammable so be careful.
- Try to untighten the thru-axle with a high-quality Allen key.
Two mini bonus tips:
- To increase your leverage, you can slide a steel pipe onto the Allen key and lengthen the handle.
- Cut a small piece from a rubber glove and place it at the tip of the Allen to make the fit snug.
Use An Extractor Bit
This method should only be used as a last resort as it will completely ruin the thru-axle. Nonetheless, it can also save the day.
An extractor bit works as follows:
- Drill a pilot hole for the extractor bit into the Allen slot of the thru-axle.
- Hammer in the extractor bit.
- Grab the extractor bit with a wrench/socket or a set of vise grips and try to loosen the axle.
This method is a bit “savage”, but it can work fairly well when the axle screw is completely stripped.
Use An Internal Pipe Wrench
Another aggressive method similar to the extractor bit would be to use an internal piper wrench.
Internal pipe wrenches are designed to grab a pipe from the inside. In our case, they can do the job of an extractor bit.
It’s first necessary to drill a hole into the axle. Then a small pipe wrench is inserted into the entrance and rotated in the direction that loosens the axle.
Obviously, this method will ruin the axle completely.
Use The Correct Side To Loosen The Axle
In general, thru-axles are loosened from the non-drive side in an anti-clockwise direction (the Allen key moves towards the front wheel).
Sometimes, however, the axle has a key slot on the drive side too. In that case, it’s still recommended to use the non-drive side. It’s possible, however, to accidentally use the drive side in the wrong direction and make the axle even tighter.
When that happens the recommended solution is to place two Allen keys in each slot and then turn them both in the direction that untightens the axle from the non-drive side.
Do not turn the Allen keys against each other in two opposite directions. This practice won’t work as you would be essentially trying to tighten and loosen the axle at the same time.
Prevent the Spreading Of The Frame Or Fork With a Luggage Strap
If the threads on the dropouts are partially damaged, it’s possible to experience the following – you keep unscrewing the thru-axle from the non-drive side, but it just clicks and doesn’t come out.
Sometimes that happens for the following reasons: 1) the dropouts spread when the axle isn’t holding them together 2) the threads are partially damaged and hold the axle in.
One of the options is to re-tighten the axle to its original specifications and then wrap nylon luggage cargo straps around the frame/fork so that the dropout cannot spread when you try to loosen the thru-axle.
Then, try to remove the axle normally.
If The Allen Key Gets Stuck In The Slot
Another issue that you may experience is a stuck Allen key in the thru-axle slot. Sometimes that happens because people use the wrong socket (e.g., a Torx wrench instead of an Allen key).
One of the options is to grab the shaft of the key with a set of pliers and slowly wiggle it out. The downside of this method is that it can strip the thru-axle’s slot.
Another way would be to heat the area with a hairdryer and then try to get the key out.
Go Back To The Bike Shop
From a time-saving perspective, one of the most effective solutions is always to pay someone else to do the job for you. Thus, if you don’t want to bother with the methods above, you can just take the bike to a professional mechanic.
Apply Anti-seize Compound Or Grease
At the end of the day, prevention is the best cure. The recommended method to prevent the thru-axle from remaining stuck inside the hub is to apply a thin film of grease or an anti-seize compound on the axle’s body and the threads.
This practice is very important if the bike is going to be used during the winter when corrosion is much more common due to moisture and the chemicals on the road used to prevent the formation of ice.