Shafts--How straight is straight enough?

[DB Golf]

This is my first hobby build on a set of irons. I pulled my True Temper Score LT shafts and would like to reuse what I can by soft stepping them 3x to convert from Stiff to Regular per the trimming instructions. I purchased new Score LT shafts for the longer irons. I rolled each shaft on a flat table to check for straightness. A surprising number of the old shafts have a pronounced wobble that I can see and hear on the table, and that I can see when I look down through the shaft from the butt end. Also, a surprising number of the new shafts have a slight wobble. I am wondering what is normal. How straight is straight enough?

 

I uploaded a video so that you can see and hear for yourself. Apologies for the 90-degree rotation on the video.

[gdb99]

I guess now we know why they are so cheap...

[Howard_Jones]

3 hours ago, DB Golf said:

This is my first hobby build on a set of irons. I pulled my True Temper Score LT shafts and would like to reuse what I can by soft stepping them 3x to convert from Stiff to Regular per the trimming instructions. I purchased new Score LT shafts for the longer irons. I rolled each shaft on a flat table to check for straightness. A surprising number of the old shafts have a pronounced wobble that I can see and hear on the table, and that I can see when I look down through the shaft from the butt end. Also, a surprising number of the new shafts have a slight wobble. I am wondering what is normal. How straight is straight enough?

 

I uploaded a video so that you can see and hear for yourself. Apologies for the 90-degree rotation on the video.

I would NOT use shaft in that condition, they are not suppose to end up on the marked, but in the  trash bin for failures, but with no quality control before the end user, this is not uncommon, also on graphite. 

Edited November 15, 2024 by Howard_Jones

[Socrates]

It depends on where they are bent.  Used shafts are commonly bent at the tip and once bent there, there are very few things you can do to fix it unless you have a lot of room to tip trim.   A lot of shafts might have a slight bend over the length of the shaft.  Not as critical as a bent tip.  Ideally, you would want all shafts to be straight and that is one reason why you pay more for better quality shafts.  You can mitigate the bend by orientating the shaft so that the bend is making the club more upright or more flat.  You can always bend the head to suit.  If I had to do it, I would set it up so it was more upright.  But only if that was my only option.

Edited November 15, 2024 by Socrates

[Stuart_G]

8 hours ago, DB Golf said:

 How straight is straight enough?

 

A gradual bend over the whole (or a large part of the shaft)  is called "residual bend."   Which is a bit different from a shaft bent only at one small part - more of what I'd call a discrete bend - which is a sign of damage.    Any shaft with signs of damage should not be used.

 

However, residual bend from the manufacturing process isn't dangerous.  But how does it effect the performance?

 

Interesting enough - Tutelman reports about a study done testing the effect of residual bend of shafts on performance.   Shafts with residual bend up to 1/4" were tested and found to have NO effect on the ball flight results or the golfers feel.

 

It's at the very bottom of this page:

 

https://www.tutelman.com/golf/shafts/allAboutSpines4.php

 

 

Now it's only one small study, so we can't really take it as gospel - but it does provide a good challenge to the preconceived ideas about how important it really is for the shaft to be perfectly straight.

 

It also lends some support to the idea that when we swing the club, we are really more swinging the head mass and than the shaft axis.

 

Edited November 15, 2024 by Stuart_G

[golferdude54]

The straightest and roundest shafts in the world used to be made by Seven Dreamers in Japan, they go under a different name and have their own website here https://www.imideandsuns.com/en/item/

[DB Golf]

8 hours ago, Howard_Jones said:

I would NOT use shaft in that condition,

@Howard_Jones, to clarify, were you referring to the pulled 8i shaft, the new shaft, or both? Thank you.

[Howard_Jones]

19 minutes ago, DB Golf said:

@Howard_Jones, to clarify, were you referring to the pulled 8i shaft, the new shaft, or both? Thank you.

Any shaft that wobbles, (tip is not centered)
I did not study the video, i just saw a wobbling shaft

[gvogel]

5 hours ago, Stuart_G said:

 

A gradual bend over the whole (or a large part of the shaft)  is called "residual bend."   Which is a bit different from a shaft bent only at one small part - more of what I'd call a discrete bend - which is a sign of damage.    Any shaft with signs of damage should not be used.

 

However, residual bend from the manufacturing process isn't dangerous.  But how does it effect the performance?

 

Interesting enough - Tutelman reports about a study done testing the effect of residual bend of shafts on performance.   Shafts with residual bend up to 1/4" were tested and found to have NO effect on the ball flight results or the golfers feel.

 

It's at the very bottom of this page:

 

https://www.tutelman.com/golf/shafts/allAboutSpines4.php

 

 

Now it's only one small study, so we can't really take it as gospel - but it does provide a good challenge to the preconceived ideas about how important it really is for the shaft to be perfectly straight.

 

It also lends some support to the idea that when we swing the club, we are really more swinging the head mass and than the shaft axis.

 

That is interesting stuff.

 

I once had a hickory brassie that had a curve in the shaft - the head was closer to the target than the grip.  I was surprised that I could actually hit good shots with the club.

[Jeff58]

2 things. First, without some critical verification, at least some of this could be your table rather than the shafts.

 

Second, while Howard may not be a metallurgist, he is absolutely correct that shafts that have been permanently deformed should be trashed. They have been stressed beyond their fatigue limit and will not behave “normally” when put in flex.

[Socrates]

1 hour ago, Jeff58 said:

2 things. First, without some critical verification, at least some of this could be your table rather than the shafts.

 

Second, while Howard may not be a metallurgist, he is absolutely correct that shafts that have been permanently deformed should be trashed. They have been stressed beyond their fatigue limit and will not behave “normally” when put in flex.

Not entirely correct.  I've seen videos of the TT plant and one of the steps before the shaft is finished is to straighten any shafts that have a bend to them.  A machine physically identifies the bend and it is bent by force until straight.  I guess if it is really bad, it is rejected and scrapped.  A slight bend in a shaft really doesn't make them something that you would trash.  Out of the 10's of 1000's of shafts I've seen from TT, only a few ever had any noticeable 'wow' to them.  Anything really bad was rejected and a credit would be issued - eventually.

[Stuart_G]

41 minutes ago, Socrates said:

Not entirely correct. 

 

Yes.  It completely depends on how the bend occurs and the actual deformation that occurs.   A shaft with residual bend will be (in practice) just as strong as one without.    It typically needs to have generated wrinkling, buckling, dents, kinking or such before the strength is significantly effected.    If it was an inherent result of the manufacturing process, it's unlikely to be a problem (of safety).  If it happened while using (or abusing) the club, or in transit, or some other accident then I would start to question the safety of the shaft.

Edited November 15, 2024 by Stuart_G

[svlido]

30 minutes ago, Socrates said:

Not entirely correct.  I've seen videos of the TT plant and one of the steps before the shaft is finished is to straighten any shafts that have a bend to them.  A machine physically identifies the bend and it is bent by force until straight.  I guess if it is really bad, it is rejected and scrapped.  A slight bend in a shaft really doesn't make them something that you would trash.  Out of the 10's of 1000's of shafts I've seen from TT, only a few ever had any noticeable 'wow' to them.  Anything really bad was rejected and a credit would be issued - eventually.

 

This is correct.  I wouldn't recommend playing a shaft that has a gradual bend, but it won't have any noticeable fatigue in a bend like the one shown in the video.  True Temper probably uses something like 1566 that has a high fatigue strength, so like @Stuart_G said, the real danger for failure would be a discrete bend or dent. 

 

[svlido]

33 minutes ago, Stuart_G said:

 

Yes.  It completely depends on how the bend occurs and the actual deformation that occurs.   A shaft with residual bend will be (in practice) just as strong as one without.    It typically needs to have generated wrinkling, buckling, dents, kinking or such before the strength is significantly effected.    If it was an inherent result of the manufacturing process, it's unlikely to be a problem (of safety).  If it happened while using (or abusing) the club, or in transit, or some other accident then I would start to question the safety of the shaft.

Case and point.  The DST Compressor

 

 

[Jeff58]

1 hour ago, Socrates said:

A machine physically identifies the bend and it is bent by force until straight.

From a strength and cold hardening standpoint, that is making it worse.

If you feel ok with accepting defective manufacturing, that’s your choice I guess. Doing so with eyes wide open would be a prerequisite, at least to me.

[DB Golf]

2 hours ago, Jeff58 said:

some of this could be your table rather than the shafts

I wondered the same and so tested again on a quartz countertop with the same results.

 

8 hours ago, Stuart_G said:

Interesting enough - Tutelman reports about a study done testing the effect of residual bend of shafts on performance.   Shafts with residual bend up to 1/4" were tested and found to have NO effect on the ball flight results or the golfers feel.

Thank you for this reference. I will go back and study up on Tutelman before proceeding. Interestingly, the very wobbly shaft in my video above is from my 8i which has been my least inconsistent club 😂

 

[Socrates]

14 minutes ago, Jeff58 said:

From a strength and cold hardening standpoint, that is making it worse.

If you feel ok with accepting defective manufacturing, that’s your choice I guess. Doing so with eyes wide open would be a prerequisite, at least to me.

Almost every steel shaft TT makes goes through this machine.  I would think nearly 100 years of production and millions of shafts (and personal contact with their production team) tells me there is nothing to worry about here.

[Stuart_G]

36 minutes ago, DB Golf said:

I wondered the same and so tested again on a quartz countertop with the same results.

 

Thank you for this reference. I will go back and study up on Tutelman before proceeding. Interestingly, the very wobbly shaft in my video above is from my 8i which has been my least inconsistent club 😂

 

 

I'm not pointing fingers but just realize, with less expensive shafts there could be the potential for other inconsistencies (such as stiffness) that could also be to blame.  And I'm assuming you're using a swing weight scale to match swing weight in the set.  If not, that's another possible source for inconsistencies among the set.

[DB Golf]

6 minutes ago, Stuart_G said:

 

I'm not pointing fingers but just realize, with less expensive shafts there could be the potential for other inconsistencies (such as stiffness) that could also be to blame.  And I'm assuming you're using a swing weight scale to match swing weight in the set.  If not, that's another possible source for inconsistencies among the set.

I very much appreciate the guidance. Yes, I plan to use a swing weight scale once I've dialed in my favorite club using @Howard_Jones's DIY tune-up method. I also have a FLO laser but no CPM tool to differentiate spine and NBP. Tutelman says not to worry about shafts with less than 3cpm difference. That's led me down a path of considering forgoing my current shaft model and researching the more expensive models I've been fitted into in the recent past. I just now renewed my membership on golfshaftreviews.info to get info on radial consistencies.

 

And back down the rabbit hole I go...