Originally Posted by repechage

6 Speed Campagnolo was throwing me too, I do not recall one, but they did make a 6 speed freewheel. It had space for two notch puller, but use a regular one and you tear up that valuable freewheel body.
The later Freehubs all used a coarse spline, which I vaguely recall changed dimension when 11 t cogs arrived.
Not relevant here.

My hunch now is there is a 6 speed freewheel on the bike, if one has not been around long enough... they are all "cassettes".