Spin

[st0wgolf08]

ok, so do we agree that you get spin from the ball sliding up the clubface? If we do, then it would seem to be the compression of the ball into the grooves would slow that, thus resulting in less spin.

[mjgraniero]

  st0wgolf08 said:

ok, so do we agree that you get spin from the ball sliding up the clubface? If we do, then it would seem to be the compression of the ball into the grooves would slow that, thus resulting in less spin.

I don't think we're in agreement there. The ball simply "sliding" up the clubface is not what creates spin. Its the friction imparted by the face and grooves which grab the ball and cause it to spin. Take a golf ball and spin it like a top (for example). To spin the ball out of your hand, you wouldn't want your hand to slide around the ball to create spin, you grab the ball to impart spin (use the friction imparted by your hand).

Hop onto youtube and look for some super slo-motion videos of a golf swing. You'll see that the ball doesn't slide up the face of the club. It may appear that way because the club is working at a downward angle. However, it is the friction created by grooves which grab the ball, thereby imparting more spin than if the face were completely smooth.

[denver_nuggs_15]

  st0wgolf08 said:

ok, so do we agree that you get spin from the ball sliding up the clubface? If we do, then it would seem to be the compression of the ball into the grooves would slow that, thus resulting in less spin.

Read my previous post. That is the physics of spin for the most part. Just read it.

[David in FL]

  st0wgolf08 said:

ok, so do we agree that you get spin from the ball sliding up the clubface? If we do, then it would seem to be the compression of the ball into the grooves would slow that, thus resulting in less spin.

I think I see where you're going wrong.....

The ball isn't sliding up the clubface, it's rotating up the clubface. That rotation becomes "spin" once the ball leaves the clubface. The grooves are what are gripping the ball and keeping it from sliding and thus, are contributing to the rotation.....or spin.

[golfire6]

Grooves are NOT the main factor in creating spin . Studies have shown that the relative flatness of the face is the main contributor to the spin of the ball . That is why so many wedges are being produced with CNC milled faces .

Grooves are only a factor in aiding the dispersion of water and debris when hitting the ball out of the rough . From the fairway , a perfectly milled clubface with NO grooves will actually impart more spin than a grooved face .

The facts are tough to hear , but that's what the studies have actually determined . Those new wedges of yours work and feel great from the fairway because they are extra-flat , not because of the extra grooves . -- K.

[David in FL]

  golfire6 said:

Grooves are NOT the main factor in creating spin . Studies have shown that the relative flatness of the face is the main contributor to the spin of the ball . That is why so many wedges are being produced with CNC milled faces .

Pls provide links to the studies to which you refer. I'd love to read them. Thanks.

[-BAMA-]

how bout this... take one of your old wedges and do a skim cut on it untill it's smooth with no grooves....

then take a new wedge out with square grooves, hit the exact same shot with the exact same ball at the exact same lie.. see what happens...

[golfire6]

"Research has shown that when the clubface is dry and no grass gets between the clubface and ball, a sand-blasted face does as well as a grooved face." -- Frank Thomas

[David in FL]

  golfire6 said:

"Research has shown that when the clubface is dry and no grass gets between the clubface and ball, a sand-blasted face does as well as a grooved face." -- Frank Thomas

a) I don't know what "does as well" means, but even if we assume that it refers to increasing spin, a "sand-blasted face" is rough, not smooth. As such a sandblasted clubface will have a higher coefficient of friction between it and the ball (as do grooves) and will also increase spin over a smooth clubface.

b) I'd still like to see any links to actual research that says that grooves don't contribute to spin.

[Fourputt]

  golfire6 said:

Grooves are NOT the main factor in creating spin . Studies have shown that the relative flatness of the face is the main contributor to the spin of the ball . That is why so many wedges are being produced with CNC milled faces .

This is what the USGA found in their testing over the last 15 years, the same tests that led to the upcoming groove change. Grooves only have a significant impact when playing from rough. The USGA used 3 wedges with identical face characteristics except for the groove. One had currently conforming square grooves, one had V-grooves, and one had no grooves at all. From fairway lies the performance differences were minimal.

See this web page and read the Second Report on Spin Generation. It should give you all you ever wanted about the subject. The other reports on that page are also interesting.

[misty_mountainhop]

Hmmm. The ball does not roll up the clubface to create spin; the length of time the ball and clubface are in contact is far too short a time for it to roll up the face. Groove size has to do with allowing you to get spin from the rough etc by channeling water and other crud away from the ball/club interface which would otherwise yield slippage; a flier. Square-edged grooves are giving more grip preventing any slippage up the clubface.

As someone else has said, a flat, but rough, surface which can grip the ball will spin pretty much the same.

Physics isn't my thing but how does this grab you:

Think about the typical wedge face as it strikes the ball. You're striking the bottom half of the ball and driving that part of the ball towards the target. The top half will rotate about the ball's centre of gravity in the opposite direction i.e. backspin. I wouldn't mind betting that some sort of momentum conservation is at work here. If you were to hit a ball at it's exact centre with a perfectly flat surface, rather than an angled wedge face, you'd get no backspin.

The same effect is happening with any spin on any ball such as tennis, table-tennis, football (soccer to you guys!)...you strike the ball a glancing blow on one side or another. Some of these have long impact times (relative to a golf ball strike) so I'm sure you'll get some roll along the impact interface.

Alternatively this could all be a load of bollox...!

Any engineers/physicists out there with an opinion?

[misty_mountainhop]

  Fourputt said:

This is what the USGA found in their testing over the last 15 years, the same tests that led to the upcoming groove change. Grooves only have a significant impact when playing from rough. The USGA used 3 wedges with identical face characteristics except for the groove. One had currently conforming square grooves, one had V-grooves, and one had no grooves at all. From fairway lies the performance differences were minimal.

Interesting USGA link that, thanks.