I think that Campagnolo changed the early cranks which had a circular cross section at the arm spider junction to the design with the thin webs to simplify manufacture but also to allow an easy indicator of accumulated fatique damage. Failure does occur there but it is more common at the pedal eye and mid-arm. I even once saw a failure around the bottom bracket axle mating surface away from the local compressive forces. If you have NOS cranks, I recommend pedal washers to protect the surface finish around the pedal hole. Keep an eye on the webs and if the crack exceeds 0.1 inch the crank is long on tooth and so careful periodic inspecions around the pedal area. Why Campy changed the web area in 1984 to prevent the web cracks, I am not sure because but they also eliminated the arm flute which without beefing up the pedal eye. Brian Blum In Berkeley.