Club head speed measurement | Golf Monthly

Does anyone know how ball speed relates to club head speed?
I had a fitting at American Golf the other day and my ball speed was 156mph with ~260 yards of carry, however the stated clubhead speed was only 97mph which doesn't make a lot of sense as that's giving a smash factor of 1.6 but I thought that maxed out at 1.5?

It was on a trackman but not sure which one it was.