Suicide is not that risky - if you don't skid and run a brake
and get it on real tight with a BB lockring behind it.
Alternatively, If you don't really care about the current wheels why not just stick a fixed cog on with some Loctite - so that it will NEVER EVER come off.
If you later need to change cogs /wheels replace the Hub / Wheel then?
Suicide is not that risky - if you don't skid and run a brake
and get it on real tight with a BB lockring behind it.
Alternatively, If you don't really care about the current wheels why not just stick a fixed cog on with some Loctite - so that it will NEVER EVER come off.
If you later need to change cogs /wheels replace the Hub / Wheel then?
I'd say thats the cheapest option?