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Old 04-30-2007, 06:15 AM
Martin Levac Martin Levac is offline
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Re: What Driver and 3 wood

Try this:

http://www.franklygolf.com/PGASeminar/spring.html

Use the equation below to determine how much actual distance you would lose, if you do lose any, between your "max" model and the other "r7" model.

v = U * ((1+e)/(1+(m/M)))

v = velocity of the ball after impact
U = velocity of clubhead immediately before impact
m = mass of ball
M = mass of clubhead
e = COR (coefficient of restitution of the clubface)

Maximum CoR permitted by the USGA: 0.830. Maximum CoR of your driver: between 0.830 and 0.930. It can't be higher than 0.930 because that's just the way of things and it must be higher than 0.830 because it's non-conforming. It could be non-conforming for another reason and have a CoR of 0.830 or less but I doubt it since it looks exactly the same as the "r7" model so it must be the CoR. Maybe it's the MOI but who knows at this point.

Just for fun:

45 / 200 = 0.225

U = 100 * ((1 + 0.78) / (1 + (45 / 200))) wooden driver
v = 145
U = 100 * ((1 + 0.83) / (1 + (45 / 200))) USGA max CoR
v = 149
U = 100 * ((1 + 0.93) / (1 + (45 / 200))) absolute practical CoR limit
v = 157

As you can see, not much of a difference between them. 157mph ball speed is good for at least 250 yards with the right conditions. Daly does about 112-115mph clubhead speed with a very good smash factor of around 1.5. Woods does over 130mph clubhead speed but doesn't have such a good smash factor when he does, it's around 1.35.

Last edited by Martin Levac; 04-30-2007 at 06:17 AM.
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