In a rational world it would be the distance from bearing center to bearing center. We live in this world so it could mean anything. I mean, after all, UDC redundantly calls cranks crank arms and calls aluminum alloy while not specifying steel as an alloy.
Thanks for the clarification… only now I’m more confused than ever Not sure if that was the real answer, or an American version of irony. I think if I lived in a rational world, I’d ride a bike just like everyone else… but then again…
I took off the bearing caps, and measured 112 mm from outside to outside of the bearings, using a mechanics caliper. Since they are 12 mm wide, that makes them 100mm from center to center.
M understanding was always that it was from bearing centreline to centreline. Of course you could have saved that half hour by just phoning Roger, who would have told you in about 15 seconds.
I thought it should have been centre to centre, however, I measured the width of my Schlumpf hub, and it was 101 from outside to outside. I though the hub was standard, so then began to wonder what ‘standard’ was. Hence the post. Turns out it’s not quite standard, and is on 89mm centres.
Phew! I’m glad someone else has noticed this too… call me a stickler for detail, but ferchrissakes, if you’re going to call something an alloy, you better start naming ingredients!
Put simply, “alloy” means “mixture”. What good does “alloy” do for someone who’s shopping for, say, a set of steel cranks?