As indicated above, normal technique is to start raising the nose - a little -at around 55-ish, and let it fly off when ready. The only reason I can think of for not doing that is if you're in a crosswind takeoff, or expecting significant windshear of turbulence airborne. In such a case it would be normal to hold the aircraft nose-level to about 65-ish, maybe a little more depending on type/weight/severity of the weather, and then rotate positively to the climb attitude. 'Holding it on' to a much higher speed risks wheelbarrowing, and excess tyre loading. Wheelbarrowing in a gusty crosswind- or at any time, really - is quite undesirable.