This is concerning, but not very if you buy your parts from a good trustworthy shop that you know deals with "real" manufacturers.
A note on total crap brakes...they're total crap. Shouldn't be a surprise but it is to some. It's not always knock-offs but just some of the cheap brands that get a lot of plugs here on the boards and other places. Here's a good example:
http://forums.evolutionm.net/evo-tir...-shacking.html
Dude is Romanian so forgive the english in that thread.
Basically, you have the fairly obvious problem of no real R&D (rotors and piston sizes too big --> horrible bias and front tires that lock up way too easily). But beyond that is where it gets interesting.
The youtube links in there show ridiculous caliper flex and a ton of variance in rotor thickness. Also, the force needed to turn the wheels. Terrible.
Unsafe? Well maybe, maybe not. But if they got all of that wrong there's no reason I would trust the brakes to hold up safely when you need them to work correctly. Certainly not worth it to me.
- Andy