There are a number of reasons why your wheels may detention or come out of true.
Newly built wheels have an initial "break-in" period where loading the wheel during the first few rides can cause spokes to settle, wind-up to detention and in some cases spoke nipples loosen. Many bike shops and wheel builders will offer an initial check-up to be done after the first few rides, when the tension is checked and adjustments are made to return the wheels tension and trueness. The need for an initial check up is the same when the wheels come stock on a new bike and tension/trueness should be checked after the first few rides. This positively impacts the long-term reliability of your wheels and is strongly recommended.
My wheel is out of true.
Wheels become out of true if the rim is overloaded and deformed from a heavy impact or repeated impacts. It is normal to need to true up your wheels from time to time over the life of the wheels. Wheels with lower end rims will require more frequent trueing and tensioning than higher end rims which resist dents and deflections better resulting in less stress placed on spokes and nipples.
My wheel has fully detensioned
Wheels can fully detension if a set of spokes begin to loosen and they are not brought back up to correct tension before extensive riding or if tension was not consistent when they were brought back up to tension. If you experience a full detentioning of your wheels, we recommend removing the tire, bringing the wheel back up to tension (verify using tension meter), and applying Spoke Freeze (made by DT Swiss™️). The wheel should not be ridden until the Spoke Freeze is fully set - generally 24-48 hours in normal environmental conditions.
Here are 2 critical tips for anytime you are working on your wheels:
Tip #1: Tension spokes properly using a spoke tension meter
If you are regularly having to retension your wheels, or find your spokes won't stay tight, this could be due to the starting tension being too low (we recommend 110-130kgf) or nipples slowly loosening each time the spoke detensions slightly when it's facing towards the ground while you are riding. Measuring spoke tension as you tighten the spokes is critical. If you plan to do the work yourself you should invest in a quality spoke tension meter, such as the ones made by Park Tool™️ or DT Swiss™️.
Tip#2: Apply thread-locking compound to spokes before tensioning and trueing
The nipples we spec are precoated with thread-locker. However, repeated truing and/or retensioning can cause this thread-locker to become less effective over time, and potentially result in repeated spoke loosening.
The solution is to bring your wheels up to tension (110-130kgf) and then use a product called Spoke Freeze, made by DT Swiss™️. Drip the Spoke Freeze at the end of the the nipple near the wrench flats where the small gap exists between the spoke and nipple. 1 small drop per nipple and then spin the wheel for a few minutes allowing the centrifugal force to pull the drop outwards toward the threads. Let the compound cure for 24-48 hours before your next ride.