So, what’s the deal?
Basically, there has been a lot of discussion in the bike press and industry recently, about the safety of using front quick release hubs in conjunction with disc brakes.
For a lot more info on the theory, have a look at James Annan’s website, but the basics are this: Disc brakes produce a lot of leverage, because they have a smaller diameter than the wheel, and they only act on one side of the fork. Because of the position of the disc caliper and the alignment of the dropouts, there is a force acting to push the wheel out of the forks. The theory is that this force is either powerful enough on it’s own to force the wheel out under hard braking, or that it causes the quick release skewer to vibrate loose - either way, the wheel is ejected from the bike at speed. Why all the discussion?
Disc brakes have been basically added on to existing designs of fork and quick release - before James Annan brought this to the attention of the industry, this particular problem had not been considered in depth.
But it’s not that clear cut. There has only been one documented case of this effect - Annan’s own, which was a tandem with custom-made forks. There have been other possible cases, but they have not been verified.
There have been many discussions on online forums about the merits or otherwise of the theory, but no-one has performed any rigorous tests. Some companies have issued statements, but for legal reasons they do not say much. The CPSC in the States is investigating, but they have not been the most balanced cycling test body on previous occasions. Discussion of the theory... Click here for some more detailed theoretical thoughts on the theories. Practical experiments... Real world testing, and how you can help. Possible solutions... Worried? This is what can be done. Does this affect any Kinetics bikes? Not really. Although some bikes we sell do have disc brakes and quick releases (like the Speedmachine), since the wheel size is smaller, the resultant forces are much too low to be a problem. They are also not (usually!) used offroad... | 
