Effect of using two heavy weights in Driver????

I currently play a Cobra F7+ driver with the 12g weight back and 2g in heel and front of the head. I play it at 43" so I ordered in some extra weights to help increase SW some. But, I started wondering what effect this will have on ball flight. If I leave the 12g in the back, then go to a 4g, 6g, 8g, etc in the front, what will happen to ball flight and spin? My guess is ball flight will start to lower and less spin. If I add more weight to the back of club, I would guess higher flight and more spin. If I keep the ratio the same as now and go 16g in the rear and 6g in the front, will flight and spin stay same as it is now? Lastly, what about two heavy weights in the back and heel of the club? Our simulators around here aren't very accurate for measuring any of the above. Thanks in advance for any help.

The actual impact on ballflight and spin will be fairly minimal until you really start changing larger amounts of weight. What will change the most is obviously the feel of the club and subsequently how you deliver it, and to a lesser extent the flex of the shaft. Adding weight will soften the tip of the shaft slightly, noticeably if you add two heavy weights. But with regards to changing in smaller increments, I would be way more concerned about how it feels to you and your swing than the tiny ball flight changes it will create.

Rule of thumb:

- More weight back = Higher MOI (more forgiveness) and potentially more dynamic loft at impact which increases launch and spin.

- More weight forward = Lower MOI (less forgiveness) and potentially less dynamic loft at impact which decreases launch and spin.

This is all assuming you swing it the exact same way and strike the exact same spots which you likely won't (no offense, even the pros aren't perfect) so experiment until you find what feels good and produces the most consistent swings and strikes.

Forget about what you think might happen based on what you think the center of gravity of the head might be effected.

1) the difference between a single 2 gm weight and moving that up to even 10+ gm wont change the c.g. location significantly. It may have a small effect on the MOI of the head (and forgiveness and gear effect). But not really ball flight.

2) More importantly, the effect it has on the swing weight feel - and how you and your swing will respond to that change in feel (path, face control, release timing face impact location, etc...) will by far be the much more dominant factor in what will happen to the results and ball flight.

So basically you just have to go play around and watch what might happen to the ball flight. If you don't have a way to accurately determine that right now, it just may have to wait. Until then, just try to find the head weight fell that gives the best feel and good center face contact (use foot powder spray) and what level of consistency you are able to monitor. If you focus on that, than chances are you've found the best amount of head weight for you.

Edit... just saw Stuart posted. Just to elaborate on that.....

All The assumptions you listed in your first post are correct but the effects of small weight additions or movements are extremely subtle.

If you keep the rear the same and radically increase the heel and front weights I imagine you will see a modest reduction in height and spin.

Most of the tests I’ve seen with moving the weights around simply don’t make huge changes in flight or spin. It’s Fairly subtle. 200-300 rpms seems to be about the max change. It’s meaningful, but not huge.

I’d just get the weight to where you like it for SW purposes and not worry too much about the rest.. There’s certainly no downside for adding weight to the sole in general. Most makers struggle like crazy to get the weight out of the crown and into the sole and/or rear of the club.

At 2 inches short of the standard 45” you are losing about 10 SW points. (About 5 per inch on a driver). At 1.6 grams per point that’s 16 grams of weight you would have to add to get back to the factory swingweight. Of course you don’t HAVE to get back the factory SW. it’s all about feel and preference. Some guys like C-9 and some guys like D-5. The club will still “work” if it’s a bit heavy or light.

I play all my woods short and I take them back up to D-2 or D-3 with hot Melt or lead tape or different weights or some combination of all 3.

My LTD is 43.5” and I added back 12 grams with hot melt and lead tape to get it to D-3.

I’m ordering an F9 and I will probably use an 18 in front and an 8 in back instead of the stock 14 and 2. That will give me 10 extra grams and then I’ll fine tune with lead tape on the heel. Of course the F9 is 45.5” I believe, so I will need to use a bit more tape.

Interesting thread. This is something I've considered as well, especially after watching the TXG video where they had Matt swing a Tensei PO (counterbalanced) and added 2 heavy weights to the Rogue SZ with great results. I believe the ball speed could potentially be higher with more weight in the head, simply because of more mass behind the ball. But the 2 responses above really sum up the technical pieces.

I believe the ball speed could potentially be higher with more weight in the head, simply because of more mass behind the ball.

Yes, in theory that's true. But for a 100 mph swing speed, it takes about 10 gm of added weight to squeeze out just 1 more mph of ball speed. But that assumes the swing speed itself doesn't change and that the player can get the same center-face (max COR) impact. And both those assumptions holding true is rare. Most players swings do not hold up well under that much manipulation of the swing weight/head weight. So in the long run, it's best to just focus on the head weight that gives the best feel, consistency and face impact conditions - that's usually the best way to get the best (useful) ball speed.

Yeah not enough weight to do much, now maybe way it feels to you can change and swing can alter as result

But ballflight if it was on a robot nothing would change

All the above-mentioned info is dead on. Unless your adding 20g or more, you won't see much difference in ball flight. I play my F7 at 44.5 w/ Copper Mamba 70TX @ D4. Had to replace one of the 2g weights with a 15g to get where it felt right. IIRC, I have 12 back, 15 heel and 2g face. I am VERY happy with the results. Now, the Copper is a counterbalenced shaft, so you may not need much more to get you where you want to be if you're using a non-CB shaft.

BT