Well look and learn. I was looking at various cranks tonight* and was studying a 1968 set of Campagnolo Record cranks that had been crudely radiused. Not very deep and leaving a rough surface. These cranks were ridden plenty by a serious racer. What I gather are new cracks extend 1/16" down from the spider joint.
So as Chuck said, there is a right and wrong way to radius. Do a good job.
* I was studying how Sugino made improvements- wider arms move the joint further up the arm and then a straight cut through the joint to eliminate the sharp edge.
Off to get the file before I forget those cracks.
Joe Bender-Zanoni Great Notch, NJ
Joe Bender-Zanoni
Great Notch, NJ
>
> As to radiusing, this is not rocket science. Any sharp 1/8" or 3/32"
> chainsaw file will do and and just a few light strokes at the end to get a
> good finish. How large a radius you put in is not very critical.
>
> Joe Bender-Zanoni
> Great Notch, NJ
> "Spent a lot of time arguing and calculating expensive radii on aircraft
> parts"