You can, but unless you are an aggressive mountain biker riding rocky hilly single-track, the vast majority of bent rotors occur when you are off the bike rather than when riding. To help in troubleshooting, we should define the different root causes that can cause a bike rotor to “get bent” and likely action required for each. They are listed from the most likely to least likely. You can also contact us at Arch Design Work to prevent bent brake rotors.
Bent Rotor – The rotor is bent by a concentrated force contacting it at any random location. The further away force is from the point the rotor is attached, the greater the tendency for bending. If you bent your rotor while riding, you will almost certainly be aware of it at the time it happens.
Misaligned Rotor – The rotor may be perfectly flat and still contact the brake pads if it is not aligned relative to the brake caliper. There can be a number of root causes, but it is generally due to misalignment during initial assembly or to loosening / damage afterward.
Warped Rotor – Rotors are very thin relative to their diameter, which increases the tendency for bending, but also for warping. What’s the difference? Bending is caused by an external force, while warping occurs from the heat generated by the pressure and relative motion of the rotor relative to the brake pad. In an ideal world this would not occur because the rotor is symmetrical and the heat is applied evenly, but part, assembly and even material variation within the rotor can cause the rotor to warp slightly. This issue is generally isolated to very aggressive/experienced riders.
With these definitions out of the way, we can better define the cause of the damage and the best course of action. This of course depends on whether you have already “Got Bent” and are looking for a fix or are reading for information.
If Your Rotor is Already “Bent”
First check that the wheel is properly seated in the frame or fork and that there are no loose fasteners (rotor misaligned rather than bent). If the rotor passes through the pads without much resistance, it likely can be straightened to the point it is usable, though it will not be as good (flat) as new. There are specialized tools (Rotor Truing Fork) for this purpose, though an adjustable wrench works in a pinch. More important than the tool is the experience, technique and patience needed for success. There are many videos on-line that will walk through the process. In my opinion the best one-stop location for bike repair and maintenance is the Park Tool video library on YouTube.
If Your Rotor is not Yet Bent
The vast majority of bent bike rotors occur when the bike is in storage, being transported or during maintenance. Damage is most likely to occur when the wheel is removed, as the rotor is fully exposed. A device designed for bike rotor protection in these instances must be effective, inexpensive and easy to install. Rotor Protect will protect all 12/15 mm thru-axle rotors with one-hand installation for less than $30. See the video where Rotor Protect resists multiple hammer blows and still allows the wheel to spin freely!
Thanks for reading. Feel free to drop me a note with your questions or comments.
Dave Archer
President
Arch Design Works
darcher@archwerx.com