I'm looking to build out my first-ever fixie, and because I'm broke and have never ridden fixed, I'm looking to do it on the cheap... but a friend has warned me that lockring conversions (you know, redishing a wheel from an old 10-speed and then threading on a track cog and securing it with a BB lockring) result in wheels dangerously prone to failure. How dangerous are they really? Is this a valid concern, or should I be able to get away with it?

Thanks!!

-chris