At 08:22 AM 4/7/2007, [EMAIL PROTECTED] wrote:
A recent example was a guy with a LA of 17.4 and spin of 4,800 and
I'd be stealing from him if I sold him a shaft with the idea that he
could reduce his LA and spin rate without changing his swing.
What sort of swing fault would tend to produce these sorts of
numbers and do you have advise on correcting?
John,
You didn't say anything about ball speed or clubhead speed. It's hard
to say much without knowing this. Yes, 4800rpm is too much spin for
almost any ball speed. But what is causing the problem and how to
solve it will vary depending on the ball speed producing those numbers.
Let's take an example. Suppose, in addition to what you've already told me:
___* The guy is getting a ball speed of 140mph. That's a
bigger-than-average hitter, but still not a big hitter. (We're
talking real numbers here, not ego-inflated numbers.)
___* He's hitting the ball near the sweet spot to get those numbers
-- whatever the sweet spot for that club is. (If he's hitting the
ball off-center, THAT is the thing you have to work on first.)
___* We're talking "normal" 200g driver head weight.
For those launch conditions, I get impact conditions that tell me two things:
(1) He's already got an upwards angle of attack of 2.6 degrees.
That's actually pretty high. I would NOT want to cure that for a
driver swing if he's hitting the sweet spot; that's actually a
low-spin swing. (Though, if he uses the same swing for irons, he hits
a lot of tops or fats.)
(2) He's got an "effective loft" at impact of almost 18 degrees.
That's a combination of the loft built into the clubhead and the
forward bend of the shaft. That's what would be needed to produce the
spin we're talking about at 140mph ball speed.
SO THIS IS AN EQUIPMENT PROBLEM. (Given my assumptions about the rest
of the numbers.) There's about 30 yards more of carry, and also more
bounce and roll, to be had by getting the effective loft down.
- Lower-loft head.
- Less face roll (that is, higher radius). This could help if he's
hitting it high on the face, because there is a shocking difference
in loft between high and low on-face strikes.
- Lower-launch shaft (probably more tip-stiff profile).
I haven't seen him swing, so I don't know if the assumptions are
right. That's why fitting should be done in person, not by email or
computer. But a computer can sure help.
WHICH BRINGS ME TO...
If you are a user of the Wishon/GolfMechanix trajectory
software, please email me off-list. Thanks.
Cheers!
DaveT
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