my new hed aerobar won't stay put in the stem. if I hit a bump it will take a nosedive. I've been increasing the torque on these bolts, and while it's better, it's still not rock solid. any advice? I'm currently using a syntace megaforce and thinking about planning to get a syntace F99 once I'm sure what length I want. any chance that the 4 bolt vs 2 bolt design would help out there?

aside from this, the hed bar is great. elegant design and very adjustable.