Q: I have a GT BMX bike that uses ball bearings in the headset. Can I buy sealed bearings and just put them in or does the frame have to be made a certain way?
This is a great question we feel many people are too embarrassed to ask about Chris. When it comes to headsets, it is best to think of them as a complete package (cups, bearings, races, seals, centering cones…), not just the “bearings”, so if you want to replace the loose bearings with sealed bearings, this can be done on any bike, but you have to replace the whole headset, not just the bearings. All you need to know is what type of headset you have; 1” threaded, 1” threadless, 1 1/8” threadless or integrated. By the sound of things you will be looking for a 1 1/8” threadless, for which there are a ton of great brands and options available. Consider a broad price selection from brands like FSA, Chris King, Cane Creek or Ciari.
To answer a similar question that Chris didn’t ask, but is closely related and some of you are probably wondering about is; are bearings interchangeable from one sealed or unsealed headset to the next? For example, could you take damaged bearings out of one headset and switch them out for a good set from another bike, with possibly another brand of headset. The answer is no. While many brands do use the same bearings, even unsealed bearings operate under an extreme amount of precision and if bearings wear or get damaged, chances are the race that they turn on is worn or damaged as well, meaning you are only setting yourself up to destroy your bearings all over again. So when in doubt, swap it all out, keep it lubed and well adjusted for a long, smooth bearing life.