Jump to content
Note: This thread is 5015 days old. We appreciate that you found this thread instead of starting a new one, but if you plan to post here please make sure it's still relevant. If not, please start a new topic. Thank you!

Recommended Posts

I've seen many threads here and on other golf forums about whether modern titanium drivers can "go dead" or "lose their pop" even in the absence of obvious structural failures like cracks etc. So I was interested to receive the following email from Tom Wishon and thought you guys might get something out of it too. Whale away!

Quote:

Titanium Driver Face Fatigue - Fact or Fiction?

TWGT receives numerous emails from regular golfers through our consumer web site ( www.twgolftech.com ) asking questions about golf equipment. We make it a point to always answer because it gives us a chance to also advise golfers of the benefits of professional clubfitting as well as to point them to the Clubmaker Locator pages on our web site to find a Clubmaker near them with whom they can work to be custom fit.


Recently a golfer contacted us to ask if it was possible for the face of a titanium driver to fatigue over time and experience a drop in the COR of the face. In addition, we have also heard the stories of long drive competitors “wearing out the face” of their drivers. Since we felt this was an interesting question related to clubhead performance, we wanted to use this topic in an article in this month’s TWGT ETECHreport newsletter.


Metal fatigue is a weakened condition in which repeated stress causes the strength of a metal part to drop below the normal designed stress threshold of the part. Micro-fractures begin to form from a high level of repeated stress which upon further stress become larger and more populated until the yield strength drops well below the level of the stress being induced on the part.


It is highly unlikely a driver could ever be hit so many times that the titanium face could develop metal fatigue. The face is simply not flexed in and out far enough to create such a condition. In addition, few drivers are ever hit more than a few thousand times in their lifetime, with a high percentage of those impacts occurring off the center of the face. It is true that much higher clubhead speeds will push the impact stress higher on the face, but again, the face is simply not flexed in and out dimensionally to a point that fatigue could occur.


From previous Finite Element Analysis projects commissioned by TWGT, at a clubhead speed of 110mph, the face of a typical 0.830 COR titanium driver flexes inward approximately 1/16” for an on-center hit. For clubhead speeds below this level, the face flexes less and for impact speeds above 110mph, it flexes inward a little more. It is however possible that the COR and resulting smash factor could drop from other factors that can change in a driver head over repeated use which are not related to any form of metal fatigue.


Chief among the factors which can drop the COR and ball speed of a driver from repeated hits to falsely give the impression that metal fatigue has set in is a permanent change of the horizontal bulge and vertical roll radii on the face. If the clubhead speed is high enough, if the face thickness is less than its designed specification, and if the head is subjected to enough impacts, the bulge and roll radii can begin to flatten after repeated hits.


One of the regular and routine tests performed on any new driver head design before production is approved is an air cannon durability test. When TWGT designs a new titanium driver, or any thin face, high COR clubhead model, final clubhead prototypes with the face thickness, bulge and roll verified to be on spec are subjected to air cannon durability tests. One of the tests typically involves firing 5,000 shots at 120mph at the center of the face. After each 500 shots, the bulge and roll radii are checked to determine if they have changed. If the face radii flatten by up to 1 inch after 5,000 hits, the head is considered to pass. However, if the face radii flatten by 1.5” or more, the head is deemed to have failed. If that happens, an analysis of the face is done to determine the cause of the failure from which adjustments of the face thickness or the heat treatment of the face material may need to be done before new prototypes are made and re tested.


Face flattening can happen with production driver heads made after all durability testing is performed if a clubhead happens to be on the minus side of the +/- tolerances for factors such as the face thickness or the bulge/roll radii, and such heads randomly end up being played by a golfer with a very high clubhead speed. The very best face thickness tolerance that can be had in the clubhead production industry is +/- 0.1mm (+/- 0.004”). Only the very best of the best of the clubhead foundries can manufacture clubheads with a face thickness tolerance of that precision. Many foundries deliver a face thickness tolerance in the area of +/-0.2mm.


If a driver head is designed such that its threshold for bulge/roll flattening is 120mph, were a golfer with a 125mph clubhead speed to happen to use a driver which comes out of production 0.1mm thinner than the face thickness design specification, within 200 hits the face radii on that head would start to flatten. Upon repeated center face hits it would continue to flatten out until very likely at around 400-500 hits, the head would no longer perform properly.


Driver and wood faces will continue to perform perfectly well when the face radius is only slightly flattened from repeated hitting. If the face radii change substantially, the face will no longer perform properly – the ball speed will drop, distance will drop and the feeling of impact becomes more “dead” – all factors which can make a golfer believe the fatigue has set into the face.


Excessive flattening of the bulge or roll is the number one reason long drive competitors experience a drop in the performance of a driver head. While some drivers built for these players with clubhead speeds as high as 150mph are made with a thicker face to begin with, some of the long drive players do not want the face thickness of their drivers increased too much because they know this drops the COR of the head and can rob them of getting the most distance possible in a competition. In those cases the competitors use a driver with a normal production face thickness and simply live with the fact their incredibly high impact speeds will most definitely flatten out the face and require replacing the head on a frequent basis.


The other way a titanium driver can give the golfer the impression the face has fatigued is when micro-fractures begin to form on the welding lines that secure the face to the body of the head which are not yet visible on the outside of the edges of the face to the eye. This can happen for several reasons – a welding defect or repeated high speed impacts near the welding lines on the face are the two predominant reasons for the beginning of a welding line failure which can affect the face performance enough to drop the COR and distance of the shot.

So the bottom line is metal fatigue in the face of a driver is highly unlikely, but most definitely changes in the bulge, roll and welding lines can happen occasionally from very high speed impacts which can reduce the performance of the driver.

Stretch.

"In the process of trial and error, our failed attempts are meant to destroy arrogance and provoke humility." -- Master Jin Kwon

Awards, Achievements, and Accolades

Wishon is the expert, for sure.  What a great write-up.  And while he said that the face would probably not show signs of fatigue, the welds  are the area where problems can occur.  I've had a couple of drivers develop cracks along the top edge, where the face is welded to the body.  I hadn't had them for very long, and I don't generate that much clubhead speed (105 mph max) so it had to have been a defect. I've also had a buddy's driver have one of the internal frame supports crack, giving him a nice rattle when he drives.  He does hit it long, so chances are the metal inside the head cracked. And we've all read about tour players who routinely break their drivers. So they can go bad through overuse, especially at higher clubhead speeds.


When a driver feels or sounds dead, it's going dead. Sure it's possible the slight muddiness doesn't really affect a player's distance. BUT, if the player swings different because of it, then it's time to move on.My G10 felt dead(ish) and if you'd seen the face you'd say it looked corpsey too. I took a chance and got it reshafted and a different style grip this time. It's alive again!

Now I know it's purely mental, but I've seen enough zombie movies to know the recently undead are not trustworthy, so the X-Tour I picked up off ebay (looked to be unhit) is going to be my driver going forward. The G10 is waiting in the wings though, because I'm a nice person.

Mizuno MP600 driver, Cleveland '09 Launcher 3-wood, Callaway FTiz 18 degree hybrid, Cleveland TA1 3-9, Scratch SS8620 47, 53, 58, Cleveland Classic 2 mid-mallet, Bridgestone B330S, Sun Mountain four5.


As an aircraft mechanic I have been aroud a lot of metal fatigue.  In my opinion though I do not think a driver will be effected by metal fatigue unless it is played as often as tour pros or people who play a lot of golf.  I am no expert, but that is just what I think.


Driver:  Ping G15 9* with Talamonti 70x shaft
3 Wood/Hybrid:  Taylormade Rescue TP 17*
3-PW Irons:  Ping G15 Green Dot KBS 90 shafts
Gap Wedge:  Cleveland 588 RTG
Sand Wedge:  Cleveland 588 RTGLob Wedge:  Cleveland 588 RTGPutter:  OdysseyBall:  Bridgestone 330-RXS or 330-SBag:  Generic


Note: This thread is 5015 days old. We appreciate that you found this thread instead of starting a new one, but if you plan to post here please make sure it's still relevant. If not, please start a new topic. Thank you!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Want to join this community?

    We'd love to have you!

    Sign Up
  • TST Partners

    PlayBetter
    TourStriker PlaneMate
    Golfer's Journal
    ShotScope
    The Stack System
    FitForGolf
    FlightScope Mevo
    Direct: Mevo, Mevo+, and Pro Package.

    Coupon Codes (save 10-20%): "IACAS" for Mevo/Stack/FitForGolf, "IACASPLUS" for Mevo+/Pro Package, and "THESANDTRAP" for ShotScope. 15% off TourStriker (no code).
  • Posts

    • I figured it was questionable as well. I too thought it was funny when he said how easy it was to set up compared to ‘more expensive devices.’ Yeah, it’s a real mess turning on my Mevo and setting it down. Maybe it’s ‘useful’ for someone who doesn’t want to spend a dime on a monitor and only wants to know distance, on a clear day.😗
    • Is all about the balance between calories consumed / digested vs calories burned though the day. The best way to lose weight is to keep your mouth shut! eat less. Consume less calories than your body needs and you will loose weight eventually. Slowly but surely. Off course you can ad extra workout to your day to burn more calories but it's a lot easier to avoid eating that 2nd burger than going out to run an hour or more to burn it. I went from 75 kilos down to 63 in 1 year just because I wasn't able to eat without pain. In that year I didn't exercise at all in that period, I was feeling bad every day. It was all about not eating enough.  2 years later I regained all my weight, just because I started eating more because I was feeling better. Also in that period I started to hit the gym and play more golf. Burned a lot more calories but also eat a LOT more food.  Fast and slow metabolism is a thing but is just an excuse to quit. If you have a slow metabolism and you want to lose weight is going to be harder for you to lose weight than a person that have fast metabolism, but is possible if you really commit to it.  Bonus track... the bigger the muscles, the more calories they burn during the day even when they are resting. So lifting weight while dieting is better than dieting with cardio.    What is real in a diet? The ideal number is to eat 500 calories less than you burn per day. In 2 week you will be 7000 calories down. That equals to 1 kilo or 2 pounds. So the idea is to loose 2 kilos / 4 pounds a months... it seams to little but over a year is a whopping 24 kilos / 48 pounds. Remember... if you commit to loose way Slowly but surely you will lose weight. Never believe when someone try's to sell you, that you can loose 20 pounds in one month. Is not possible or healthy.  Another thing when you start to diet is don't get discouraged if after a week you stop going down in weight, even you start to go up. is normal, when you start to diet, you normally loose a couple pounds in water, yes that water is from water retention from your previous diet.  Just keep on grinding and you will keep loosing weight eventually. Also worth pointing out, the body always tends to stay the same. If your weight is 100 and you start a diet, you body is going to notice that the calories intake is been dramatically reduced, so in order to keep you at 100 kilos is going to slow down your metabolism in order for you to burn less calories. Eventually this is not going to be enough and you will start to loose weight but your body is not going to make it easy on you.     
    • I feel like that video was an incredible waste of time. Because the guy kept saying carry and clearly the device is saying total distance. With carry distance also on there, but he's not calling that out. They when he's comparing it to the Trackman he continues to say "carry", when again the device says total. With his being so inexact in the use of the terms carry and total distances I literally have no idea how accurate or inaccurate that thing is.  I will say the putting was kind of neat. 
    • I watched that video a few days ago. I chuckled at him saying it is so much easier to set up than plopping a GC3 down and turning it on. I love how he did his test hitting AlmostGolf balls, too. 🤦🏼‍♂️ Do I think this is remotely accurate? No. It's measuring ball speed. It's not getting spin or anything like that. Certainly not in dim conditions outside at night.
    • Has anyone tried this? Just came across it. 
×
×
  • Create New...

Important Information

Welcome to TST! Signing up is free, and you'll see fewer ads and can talk with fellow golf enthusiasts! By using TST, you agree to our Terms of Use, our Privacy Policy, and our Guidelines.

The popup will be closed in 10 seconds...