There really isn't any inherent reason a conversion is more or less likely to fail than a bike designed for fixed-gear use (barring the rear wheel falling out of the front of horizontal dropouts, which is easily avoided). The most important thing is that your bike is well maintained- bolts are tight, threads aren't stripped, chain tension is correct, drivetrain parts aren't worn, brake pads are functional. The reason conversions can be dangerous is that people pull bikes from the 1970s out of their damp garages, Loctite themselves a suicide hub, and then take off into traffic. Not long after, any number of simple things goes wrong (a loose crankarm falls off, they realize the brake pads are dry rotted and do not contribute to stopping the bike, a rusty or worn chain snaps, a rusty frame breaks in half, etc.). These are all also things that can happen with a brand new bike, they are just less likely because some of them take time to develop into a real issue.

If you are good with bikes, do an exhaustive once-over before you build it, checking and lubing threads, looking for rust, etc. If you don't feel qualified, bring it to a shop for a once-over by a mechanic (but make sure you have a good shop, because there are a lot of mechanics I wouldn't let touch my bikes).

The last thing is be smart. "Suicide hubs" are called that for a reason. A functioning fixed/free wheelset can be had for close to $100, and no matter how zen meditative voodoo you are in traffic, no amount of skidzzz will stop you if a chain snaps. If safe is a priority, use a front brake and learn to use it.


If you do these things, your conversion will be safer than most fixed gear bikes out there, whether brand new or from 1972. That looks like a sweet frame- looking at it makes me think polished silver should be added liberally.