Perimeter weighted driver experiment

[Daeldalus]

I have been interested in whether or not modern golf physics could successfully be applied to pre-metal era woods. After some research that really didn't turn up much, I decided to test some of it for myself. The first thing I wanted to test was perimeter weighting. The plan I made for testing was as follows.

1. Find a cheap wooden driver that is in playable condition but that no one would be sad about if I accidentally ruined.

2. Test it as is for length, weight, sound, feel, playability, and head to head against another driver from the era that is well known for its performance( I decided on using a ping karsten II I had already) and record the results. 

3. Remove weight from the front, center, and top of the clubhead. Then redistribute it along the back, sides, and bottom. This would be accomplished by drilling out the front weight port and hollowing out the center of the head as well as drilling deeply into the sides of the head and capping the holes off. Weight would then be placed back where it is needed by gluing brass weights into appropriate holes. 

4. Retest the club using the same methods as before and record the results.

[Daeldalus]

The club I ended up finding for the experiment was a late 70s model Spalding Executive. Here are some pictures of its original condition except that I forgot to take a photo of the bottom until after I had already drilled out the front weight port.

[Daeldalus]

The test results for before altering the club:

Length: 43 inches

Weight: 367 grams

Feel average: 77 out 100 

The very subjective way I test feel is by hitting 50ish balls with it and assigning a score out of 100 for each shot based on feel, sound, shot direction, speed etc.

 

Sound: good, in line with my other classic persimmon and laminated drivers.

 

Head to head against Ping Karsten II: Ping wins 3 rounds to 2 by an average of 1 percent. 

The also fairly subjective way I test head to head. I hit alternating shots with each club 10 balls per club using distance, accuracy, trajectory, feel, and sound as the deciding factors. I also assign a 1 to 100 score for each shot in order to keep better statistics on the match.

I was honestly surprised at how well the executive did without any modifications. Pretty close to beating the Ping.

 

Also worth noting that I did not do the tests on the same day so I was fresh for both.

 

Edited May 6, 2022 by Daeldalus

[Daeldalus]

Now on to the modifications. 

I couldn't get the weight port screw to move so I just drilled it out. Between the screw and the lead in the weight port I removed 10 grams. I then drilled out wood around the weight port to hollow the inside of the head. I made sure to not go towards the face of the club in order to keep the strength. This removed an additional 5 grams. I then sanded off the clearcoat and sanded the paint enough to make sure of where I would be drilling to remove more internal weight. I decided on drilling in a rough honeycomb pattern on the toe of the club in order to keep as much structural strength as I could and remove as much weight from the middle of the club as possible. I drilled 28 holes in the toe, 3 holes in the heel, and 4 holes in the rear of the club. That plus the sanding took off another 12 grams weight. Total club weight 340 grams 27 grams removed total.

[Daeldalus]

After that it was on to the actual weighting. The holes that I was not going to put brass weights in I glued in caps of wooden dowel rod. The dowel rod was measured to be roughly 1/3 the density of the laminated maple. This added strength back into the club while leaving the inside of holes open. The other holes got precisely measured pieces of brass rod glued in and sanded smooth. I decided to put slightly more weight in the heel of the club (2 grams more) than the toe because I like a bit more heel weight but this method could be used to put the extra weight anywhere that suits you.

 

I hit the club because I was curious. The big open hole in the bottom made it sound very odd. I was planning to fill it with foam anyway but that sealed the decision.

[Daeldalus]

Then it was just a matter of making it look pretty. Absolutely not necessary but I wanted to given how much time I had spent on this. 

 

It got a fresh coat of black paint and took the paint back off of the brass weights to show them off. I got a bit sloppy there and had to paint back around them a bit. To be fair though, this whole project has been a bit sloppy but this wasn't being done for beauty. It was for performance(hopefully)

[Daeldalus]

I think at this point it is important for me to stop to talk about my expectations with this experiment. I wasn't going into this thinking that I could just slap together a club with a bit of high school physics and come out with something to rival modern engineering. 

 

I honestly have believed from the start of this experiment that it could likely end up with a shattered clubhead or with something that is noticeably worse than what I started with. But I just had to see where this took me. I had to see it through good or bad.

Edited May 6, 2022 by Daeldalus

[Daeldalus]

The test results for after altering the club:

Length: 43 inches

Weight: 365 grams (I chose to lighten by 2 grams)

Feel average: 79.5 out 100 

I was very surprised by this result. The club feels and sounds amazing. It is especially good on off center hits. It is enough better that I am pretty sure that even bias couldn't account for the difference.

 

Sound: good, in line with my other classic persimmon and laminated drivers. Maybe just a tiny bit better than before. Maybe. Could be wishful thinking but definitely not worse than before.

 

Head to head against Ping Karsten II: Experiment wins 3 rounds to 2 by an average of 3 percent. Another surprise, the experiment was much more on line than before and had fewer big misses both directions than it did before. Trajectory and distance were similar enough before and after that I can't tell a difference. 

 

In the end this experiment is good enough that it has knocked my gamer persimmon out of the bag and I will be playing this for my vintage rounds. I am personally kinda shocked by this. I really like my current gamer. Powerbilt citation. I didn't come into this thinking that it would be better than my current favorite. 

[Daeldalus]

Any questions? 

 

Would you like to see me test it in any other ways?

I have access to a cheap launch monitor that can show me CHS and ball speed. If anyone wanted more solid data. 

I could do head to head against a modern driver with the same shaft length.

 

[AdamMH]

Fun experiment! I had an idea of doing something like this with bent brass bar around the back of the head, but never really got around to putting the effort in. I'm fairly surprised that you preferred the experiment driver over real persimmon though.

[Daeldalus]

22 minutes ago, AdamMH said:

I'm fairly surprised that you preferred the experiment driver over real persimmon though.

Me too. Though only time will tell if it is just a honeymoon phase.

 

Or if it is just because I want it to be better since I put all that work into it.

[Valtiel]

Pretty cool overall! 27g of weight freed up is pretty significant, especially since 15g of that came from the weight port which is forward in the head. Replacing 25g of that lost weight around the head would have definitely increased MOI so mishits should perform better. If you wanted to do a "maximum" MOI test then concentrating as much of the redistributed weight as far away from the face as possible would take it even further. Perimeter weighting (heel/toe) isn't as effective at increasing forgiveness as backweighting on woods, although how much you could actually cram in the rearmost portion of the head might be limited. Tungsten dowels would probably have to be used over brass for increased mass. Thanks for sharing though, looks cool too!

[Daeldalus]

1 hour ago, Valtiel said:

 If you wanted to do a "maximum" MOI test then concentrating as much of the redistributed weight as far away from the face as possible would take it even further. Perimeter weighting (heel/toe) isn't as effective at increasing forgiveness as backweighting on woods, although how much you could actually cram in the rearmost portion of the head might be limited. Tungsten dowels would probably have to be used over brass for increased mass.

 

I thought about using tungsten but decided against it because it is expensive, very hard to cut, and brass looks cooler/more appropriate. 

 

I had read that back weighting is more effective so all of the more forward weights are pretty thin. The front 6 weights on the toe side are about 1/8 of an inch each for a total of roughly 1.5 grams. The rear weights are much larger overall. 

[Swingingk]

Neat experiment, I'm glad you shared it.  I just wanted to add something on the tungsten weight idea.  You might consider visiting a local machine shop and ask for some worn out 1/4" carbide endmills.  You'll get them for free.  The carbide would be much heavier than brass in comparable sizes.  You won't be able to saw them to length but they will break readily when clamped in a vise and struck with a hammer.  You could insert the broken end into the wood to hide the jagged edges.  Don't forget to wear your safety goggles when snapping them off!

[weakputt]

 

1965 Sylvain F. "Steve" Biltz Jr. – Centurion set.

1w, 3w, 4w, & 5w laminated wood set.

1965 Pat. #D206888 for the first woods that had field adjustable weights.

Custom made for Jerry Helit. 

Blitz was from Scottsdale, Arizona.

[Nels55]

That's a pretty cool build!  I guess that if the ruling bodies had outlawed metal and composite clubheads by specifying wood only for material aside from sole plate and face insert your build is something like what we would all be playing now.  It would be interesting to see how far wood could be taken in the hollow body foam filled or whatever direction...

 

Nice work!

[No_Catchy_Nickname]

On 5/7/2022 at 2:45 AM, Daeldalus said:

Me too. Though only time will tell if it is just a honeymoon phase.

 

Or if it is just because I want it to be better since I put all that work into it.

 

Really interesting read. I can't believe I missed this when you first posted it. 

 

Are you still playing the club, and are you still getting better results than your Ping?

[Daeldalus]

On 6/22/2022 at 8:55 AM, No_Catchy_Nickname said:

 

Really interesting read. I can't believe I missed this when you first posted it. 

 

Are you still playing the club, and are you still getting better results than your Ping?

I have been quite busy since I made this but I have played 2 9 hole rounds with my vintage clubs and this driver has performed well. I had 4 drives over 300 yards. One was 324. I generally don't get that kind of yardage even with my modern driver. To be fair though it has been exceptionally dry recently and the fairways are hard. The ball rolls and rolls. I estimate my carry to be like 240-250 on the flushed ones. 

 

All in all, this club is staying in the bag for the foreseeable future.