drilling a DIY fixed cog
cold wet weather is getting to me...
I read a DIY article on 63XC about making fixie cogs for your disc hub and thought I should try it. I went out and bought a cobalt bit today to drill out a 16t cog from a 7-speed cassette to fit on my disc hub to fixie-ize it. I nailed the cog to a work bench so it would not move, dripped a little oil on the cog to serve as cutting oil and went to town. after ten minutes of pounding at the cog at varying speeds, i barely scratched the cog.
so what am I doing wrong here? is the bit crap, or is it my technique? I would just buy a Tomicog but I don't know what size I would want and I don't know if i'll even like riding fixed offroad. I don't have $35 to just toss out the window on a gamble.
Riding fixed offroad is fun for certain trails and for scenery riding. Give it a whirl. For gearing, do one or two cogs less than you would do on a SS.
As for technique. You'll ruin your bit soon, don't worry. Hand drills will absolutely not work. I've tried multiple times with multiple cobalt bits. I've been told that a drill press with a really low RPM setting might get the job down with the same cobalt bit.
Word of advice? Just buy a TomiCog or cog from VeloSolo and sell it later if you don't like it. It'll save you a lot of time, it'll be perfect and it'll have resell value.
damn. I'll see if I can find someone with a drill press or just save my pennies for a Tomicog. or does anyone want to sell me one?
What kind of bit did you use? I've drilled through some tough stuff with some ti bits.
it was a Hitachi cobalt bit. it was about $4 at Home Depot.
It has been suggested that I try starting with a center drill bit, but if i spend more money on tools, i might as well cut my losses now and just buy a Tomicog. that would have happened by now but I am unemployed and bored. it was a struggle to justify springing the $4 for the drill but. I have a job interview next week, wish me luck, for my sake and the sake of my more mutilated bike.