True Length Technology

[Lumlum]

I guess LowPost is probably the man with the know how here...

As you may have seen in my other post I recently ordered a bunch of Maltby components to have some clubs made. I also went for a fitting with a PCS fitter, who had me hit a whole bunch of different 7 irons. He determined that I needed stiff flex, 1 inch over, 3deg upright, and is currently building me my 7 iron to that spec.

I then, foolishly, started reading more and more into TLT and I am intrigued... Unfortunately, the only TLT fitter nearby is pretty expensive. As I understand it, the system uses basic trigonometry to achieve a constant height off the ground for the butt of the club, allowing one to use the same stance, posture and swing for every club in the bag. I assume this is done by using standard lie progression through the set (ie increasing by 0.5deg or 1deg per club) and then setting the lengths accordingly to achieve the ideal butt height above the ground. Does this sound about right?

What I am not so sure is what happens next. Does the builder need to play around with weighting etc? Will this automatically produce a MOI matched set, or is further work required for that? What are the benefits of MOI matching?

There are loads of other questions I have but probably should leave it at that for the time being...

Thanks very much

[LowPost42]

Re: True Length Technology

Indeed I seem to be the only visible TLT fitter on this board.

It's only foolishness as you'll learn that a little knowledge is dangerous!

TLT does not automatically MOI or SW match a set - weight needs to be modified (usually added) to do either.

MOI matching is the 'evolution of SW matching' in my opinion. It's a little more empirical, and focuses more on things about the club that make more sense to modify the feel.

The main departure from SW matching is in the grip end. We know we can change butt-end weight to fool the swingweight scale. It moves the balance point and now I can achieve whatever SW your heart desires. However, weight under your hands doesn't influence head feel nearly as much as weight at the head end or changing length - and MOI matching addresses and corrects for this. Certainly there is a feel change when you change the weight at the butt end, but not nearly to the degree that SW matching allows.

More or less, both SW and MOI matching are methods of 'heft matching' - that is, getting your clubs to feel the same when you swing them. MOI matching produces a 'incremental SW matched set' - so the PW will SW heavier than the 4i, but swing the clubs blindfolded, and you can't tell which is which (which is the point).

Before people argue that the ball position needs to move up and back according to the club so you want different feeling clubs, MOI'd clubs all play from the same position forward or back (due to the same feel and hence same release point), and TLT MOI clubs go even further as the distance from your toe line doesn't change, either.

This doesn't mean you can't hit high shots or low shots with a TLT MOI set - but that for your stock shots, the ball position is more or less the same.

Hope it helps!

[Lumlum]

Re: True Length Technology

OK, you've opened up a whole new can of worms.

What do you mean by "TLT MOI clubs go even further as the distance from your toe line doesn't change, either."? Surely you position the ball further away from you with the longer irons?

So, if you were to have a MOI matched set, and the MOI and overall weight of each club felt good then swing weight becomes irrelevant? How does one go about MOI matching? Is there anyway without fancy expensive equipment?

If it turns out the the 7 iron that I am having built feels really good and fits my ideal 'athletic position' could I then use similar trig as in the TLT system to work out the ideal lengths of the rest of the clubs? Once I've got this how do I go about sorting out the weights to get a good MOI match?

I really could get into this club building gig, really fascinating but a little on the expensive side.

Thanks again

[LowPost42]

Re: True Length Technology

OK, the distance does change, but from a playability standpoint, it's not noticeable.

Yes, MOI matching makes swingweight irrelevant. Now, I mean, you can still get the SW of your clubs, and record the data, but generally MOI matched clubs don't also SW the same. There are some variations, but by and large it doesn't happen.

As for the rest of it, yes, you could use the trig to figure out your lengths. And you'll want to google 'Dave Tutleman' and read his stuff, especially regarding MOI matching.

[Lumlum]

Re: True Length Technology

Thanks again.

I had a look at that Tutelman website, very interesting indeed. I have a lot of reading ahead of me!

I used the formulae that he provided for both swingweight and MOI in my spreadsheet and found some interesting results. Firstly I know that the formulae only give approximations and that I should take the results provided with a large pinch of salt.

That being said, I have estimated that the 7 iron being made is going to be somewhere in the low to mid range of the 'D' scale. The reason I cannot be more precise is that I don't know what length he is building the club to, only that it is an inch over 'standard'... What, in your opinion, is the standard length of a 7 iron? Once I have the club back it will be very interesting to find out what the measured swingweight and with the actual length I can compared measured to estimated to see how close they model is. The next thing to do will be to hit a bucket or two of balls with the club to see how it feels and to see if this represents my ideal athletic position as the majority of my calculations are based on this one club. If I hate it I definitely don't want to build an entire set around it.

I am now somewhat regretting not getting the KE4 Tours as my calculations show that in order to get a set of clubs that are built to my ideal length (somewhat similar to TLT) and that are also approximately MOI matched, I need to make some large headweight changes (the addition of upto 15g for the hybrid, and the reduction of 15g in the wedges). Obviously adding weight is a lot easier than removing it. The only way I can think of to reduce the MOI (and SW for that matter) is to increase the lie which will allow me to use a shorter shaft whilst still achieving the same butt height, but this has obvious playability issues, otherwise I need to start removing metal from my heads. The KE4s on the other hand would have been easy!

How do you go about MOI matching (or even SW matching) as set of TLT'd clubs when the lengths are so close together? Adjustable weight clubs obviously help. Or do you start with the wedges and work your way up?

Please help!!!

[LowPost42]

Re: True Length Technology

There are two main ways to MOI match - manipulate the length, or manipulate the weight. Since length is static in most builds, weight is the usual dynamic variable.

In my experience, you can either MOI match to the heaviest club (so generally, of 8 clubs, there are 7 with weight added), or you can match to the favourite and may have to grind hosel tops or soles to lose weight. As a strong guideline, your longest club will have the most MOI.

Sorry for the short answers today - today is busy!