Things that make you go Hmmmmmmmm!

[fozcycle]

As I was reading the excellent Paderson Kinetix shaft reviews, I came across the discussion concerning Spin created off the Driver.  Thanks to Jason from Paderson for the following post:

 

 

Technical Time Out!

Relative to lesser of the oblique impacts, driver, fairway, hybrid:
1. Translating up the face, (sliding) will increase spin. The affect is linear in terms of compressive loading.
2. The greater the distance the ball slides prior to the point of separation, the greater it will spin.
3. Luberous coatings, lower the coefficient of friction! The lower the coefficient of friction, the less distance the ball will travel (compressively load) up the face. The rounder the ball will remain, the less it will spin. The greater energy it has to project = higher ball speed lower spin.
4. COR is a measurement of loss. Contrary to marketing, the "spring-like" affect is in fact, face compliance in the normal direction. IT IS NOT possible for a passive unsupported face (as found in all USGA compliant drivers) to rebound in time, during the secong half of the impact event, so as to trampoline the ball outbound. We do however tailor face compliance, to minimizing ball travel, reducing the quantity of deformation in the ball (compression / flattening) over the impact event. This will achieve a rounder golf ball, higher outbound ball speed at the point of separation. The higher the COR in a driver or HOT fairway metal, the greater the face deflection. The more the face complies, the less the ball will flatten.
5. Conversely, with oblique impacts, say wedges, whereby high spin is the desired affect. We tailor clubheads around material hardness. The harder the face (head) material, the greater the affective force load of impact, regardless of swing speed. The Harder the face, the more the ball will compressively load in the face normal direction, the less the ball will travel up the face, the greater it will spin. In conjunction with faces having inherently higher coefficient of friction and face and groove spec (latter within USGA' defined guidelines) work to channel moisture, affectively creating "rolling friction".

 

My question to be ponderd is this:  My old wooden driver had grooves on the face......Why don't the modern metal drivers have grooves on the face?  Would this eliminate slippage up the clubface thereby reducing spin and providing for more distance?

[fozcycle]

So maybe I titled this wrong? I read Jason's reply in another thread and wondered why the lines on the drivers disappeared. Just wondering, so anybody can chime in here and tell us your thoughts on this.

[BIG STU]

Yeah you got me thinking too on that. With persimmon I would say it may have something to do with just the opposite of what Jason stated about newer models. With the balata balls and compression at the time it helped the ball stay on the clubface a little longer for better control. Also in those days you had different insert material avaible I personally preferred the pressed fiber type over the plastic and aluminum type. remember in those days we did not know a bunch about spin rates with woods. I can remember though I had a Northwestern laminate 6 wood and had a clubmaker that I knew at the time put a fiber face insert on it so I could control it better over the stock plastic insert. He also grooved it out some so I could stop it better. there were no USGA groove rules on woods at the time. funny thing now that you mentioned it with my somewhat modern V-Steel 7 and 9 woods they do not have any real grooves either and with the modern ball I can stop them just as well as I did that old 6 wood with a balata ball. Man you got the old brain factory smoking early this morning

[fozcycle]

I had a set of PowerBilt Citation woods (1,2,3,4) and each had a plastic insert with grooves and two brass screws.......remember the expression "hit it between the screws". I wonder if anyone has made a metal wood with grooves. I have never seen one and just wondered why not?

[evershady]

The new Bridgestone J715 has a spin milled face like a similar to putter and it swings amazing. One of the Hack To Jack guys got it this my favorite driver I have test hit this year.

[fozcycle]

Thanks evershady, the VP of our club is getting new Bridgestone clubs this month. I'll check out the driver.