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Date: 13 Apr 2007 08:30:13
From: Sandman
Subject: Source for driver specs?

Has anyone (or any agency, sanctioning body, independent testing lab,
etc.) compiled stats for drivers? I'd like to compare the stats for
drivers manufactured and sold in the last few years; in particular,
I'd like to see coefficients of restitution and moments of inertia
(and it may be that these days all of the COR values are pretty much
up at the maximum allowed of 0.830). I'm primarily interested in the
numbers for the driver heads; if you were to work in all the specs for
the various shafts available on each driver, you'd have quite a load
on your hands. I've performed some searches without much success so
far -

It would be greatly appreciated if someone could point me to such a
table -

B





 
Date: 14 Apr 2007 11:08:32
From: david s-a
Subject: Re: Source for driver specs?
Sandman wrote:
> Has anyone (or any agency, sanctioning body, independent testing lab,
> etc.) compiled stats for drivers? I'd like to compare the stats for
> drivers manufactured and sold in the last few years; in particular,
> I'd like to see coefficients of restitution and moments of inertia
> (and it may be that these days all of the COR values are pretty much
> up at the maximum allowed of 0.830). I'm primarily interested in the
> numbers for the driver heads; if you were to work in all the specs for
> the various shafts available on each driver, you'd have quite a load
> on your hands. I've performed some searches without much success so
> far -


In the absence of such a comprehensive table there is much anecdotal
evidence out there on typical COR values accorded to different eras.

Typical wooden headed drivers COR'd about 0.74, early steel headed
drivers COR about 0.78, early titanium headed drivers about 0.80, 'COR'
designed titanium headed drivers now range upto a thoretical maximum in
the region of 0.90. R&A/USGA rules limit COR design to a figure
(characteristic time) that *correlates* with a COR of 0.830 when struck
with a clubhead speed of 109mph. Unfortunately a clubface 'designed' to
have an optimum 0.830 COR at a much lower clubhead speed (typical for
most hackers) will exceed the new 'characteristic time' limit test
imposed by the R&A/USGA. Such a clubface would probably collapse with a
109mph clubhead speed anyway. (This will most likely improve over time
subject to improvements in useable alloys and their heat treatment).

Swingweight matched clubs are a reasonably close emulation of MOI
matched clubs except they do not take account of overall clubweight,
which is a necessary feature when matching the clubs to the player. 'D0'
to 'D4' has been a fairly standard range for mens clubs since the mid
1920's, with 'C4' to 'C8' being the preferred range for womens clubs.

cheers
david


 
Date: 13 Apr 2007 19:21:11
From: BAR
Subject: Re: Source for driver specs?
Sandman wrote:
> Has anyone (or any agency, sanctioning body, independent testing lab,
> etc.) compiled stats for drivers? I'd like to compare the stats for
> drivers manufactured and sold in the last few years; in particular,
> I'd like to see coefficients of restitution and moments of inertia
> (and it may be that these days all of the COR values are pretty much
> up at the maximum allowed of 0.830). I'm primarily interested in the
> numbers for the driver heads; if you were to work in all the specs for
> the various shafts available on each driver, you'd have quite a load
> on your hands. I've performed some searches without much success so
> far -
>
> It would be greatly appreciated if someone could point me to such a
> table -

Some wise man said a while ago "just hit the damn ball!"


  
Date: 13 Apr 2007 23:03:14
From:
Subject: Re: Source for driver specs?
On Fri, 13 Apr 2007 19:21:11 -0400, BAR <screwed@you.com > wrote:

>Sandman wrote:
>> Has anyone (or any agency, sanctioning body, independent testing lab,
>> etc.) compiled stats for drivers? I'd like to compare the stats for
>> drivers manufactured and sold in the last few years; in particular,
>> I'd like to see coefficients of restitution and moments of inertia
>> (and it may be that these days all of the COR values are pretty much
>> up at the maximum allowed of 0.830). I'm primarily interested in the
>> numbers for the driver heads; if you were to work in all the specs for
>> the various shafts available on each driver, you'd have quite a load
>> on your hands. I've performed some searches without much success so
>> far -
>>
>> It would be greatly appreciated if someone could point me to such a
>> table -
>
>Some wise man said a while ago "just hit the damn ball!"


Amen, brother!

Craig

"Nothing matters but the weekend, from a Tuesday point of view."