I broke the bearing cage in the top of my headset on my '95 M2. The headset was the original Aheadset, and was about 10 years old when it broke. The bottom bearing cage was intact. The bike was used for trail riding and killed several suspension forks (I'm currently on my fourth and need a new one), so I guess you could say that it has been abused. The new headset in a Cane Creek with sealed bearings and has not had any issues.