chiromikey

I'll hit you up the next time I'm in town! ;)

What part of NorCal are you? I visit the northern Bay Area often and would love to play with a TSGer!

How are we expected to snatch up your hand-me-downs...AND save up for our own SD shafts??!!

Wow, now that's a letter of endorsement if I ever read one!

Japanese sports cars are special but I've yet to see a design team rival anything from Italy...until now!

Good review mp! I forgot, was your shaft built through the questionare or fitting?

How's the distance? Are they a club short like the P1's?

VERY cool!! Is this the kind of plating options you will soon be offering?

I have a FEX and FEX WBQ and both are great. The WBQ is meant to be played a bit longer in length and it seems the harder I go after it the better it performs! It's my gamer over several Crazy shafts right now.

Using SD's equation, a good estimate appears to be that every 10g head weight roughly equals 1mph swing speed. So if you give up 20g head weight you need to gain 2mph to get the same distance or at least 3mph to achieve an overall gain. Another bit if applicable info for anyone that wants to estimate what this means for actual distance: According to Trackman's chart of 2010 data, using 90-110mph swing speeds, each mph yields approximately 2.6yds total distance.

I can agree with that. It was the launch monitor results with a Ping i15 that initially got me curious about head weight. I have a very flat swing that can cause the head to not stay down at impact so I wondered if adding head weight would help me not have to concentrate on keeping my swing on plane. Besides achieving my initial goal we discovered that as we added more and more head weight my swing speed didn't decrease like we expected and I was gaining a few yards. I really don't have any specific questions for SD but when I finally make it to Japan I hope you and SD can make time for me!

I do the math later to figure out the relationship between head speed and mass and what the trade off/gains are.

I think you're right that in theory most people are capable of swinging a lighter club faster...when they give 100%. On the course I wouldn't be surprised if most people swing within a comfort zone which yields a similar swing speed for both. My assertion is, and I stated this in my very first post in the original thread, is that we should swing the heaviest head that doesn't decrease swing speed by more than 1mph for maximum distance.

Here's the math using a 190g driver head vs a 220g head. I used .83 for COR and the USGA's maximum allowable weight of 45.93g for a golf ball.

As soon as you perform the equation you'll understand...

In the real world I might swing the lighter club faster for the first few swings until my body gets used to it then I go back to my comfort zone. Since I never swing 100% on the course I tend to maintain a comfortable and similar swing speed with a heavy or light head. In my case that means I get more distance with the heavier driver. Forget F=ma if you don't think it applies to golf and use the Sevendreamers equation (which is a golf specific derivative of the same equation btw). They BOTH prove the same thing...increasing head mass or head speed equals higher ball speed (distance). The ONLY way SD can assert a lighter club equals higher ball speed is if they are also using a higher value for swing speed and their equation proves this. Lower weight alone is physically impossible to achieve this.

I think we have to isolate it to head weight rather than overall weight because it's mostly just head weight that transfers momentum during the collision with the ball. And yes, I think a robot test would prove this. This is why I think we may see future marketing towards heavier heads. As shaft technology continues to advance, ultra light shafts will allow companies to re-position that unused weight back in the head, therefor offering players the theory that they can maintain their current swing speed while also having more mass behind the ball. I never expected to be arguing the merits of a heavy head when I started my experiments but I'm amazed at how much swing speed was unaffected (in my swing) as I kept adding more and more weight to my driver.

Nothing is constant when you add the human element so a debate involving those variables becomes muddy very quickly. However, physics does remain constant and that's the area I'm debating. If a player swings the heaviest head that they can consistently find the sweet spot with AND they don't give up any swing speed over the lighter head, they WILL hit the ball farther. Plug the numbers into the Sevendreamers equation for initial ball velocity that you posted in the other thread and you'll understand what I'm talking about.

C'mon C...quit teasing us with these washed out pics with plastic on them. Let's see what these really look like! ;)

They're going lighter because they're selling the theory that people can swing the lighter club faster which also offers more distance. Either increase mass or speed, both offer more distance.

Physics absolutely proves heavier equals more distance...as long as swing speed remains constant. If you consider COR, ball mass, and launch conditions as constants, Head mass and head speed are the only contributing factors that influence ball speed (acceleration). Increasing either one of those two variables equals more distance. Imho, brands are going lighter because technology is allowing them to do so. Lighter can, for many, equal higher swing speed so you have brands able to sell the theory of more distance. This could be considered a gimmick as much as any other since lighter doesn't magically help you hit the sweet spot even if you are able to swing faster. And don't be surprised when companies start going back to added mass behind the ball for more distance after they wear out the lighter is better campaign.

Just proving the fact that, swing speed being equal, more mass equal more distance. However, nob makes a very obvious and valid point, the human element adds many variables.

I understand the direction golf is going...but I also understand it's because (in theory) a lighter club is supposed to allow the player to swing faster. Just know that whether it's F=ma or the Sevendreamers equation, physics proves that a heavier club head equals more distance.

I just saw your edit...I'm not at an airport but I'm bored and can't sleep.In your example, you're correct in that there is no acceleration...BEFORE contact. Knowing Newton's 3rd law we know there's an equal but opposite force applied to the truck and your body when they do contact. We can either multiply the mass of the truck by it's minimal negative acceleration as it smashes you into it's radiator or we can multiply your mass by your nearly instant acceleration from 0-60mph. Either way, it's going to be a lot of force due to significant mass or significant acceleration, respectively. Newton's 2nd law is definitely F=ma, not sure why the site you found shows something different.

I'm still calling out the assertion that a lighter weight equals higher ball speed (unless it increases head speed) but other than that I want to go to Japan more than ever now.