MOI Balance Index

[Richie3Jack]

I saw MOI Balance Index (MBI) a while ago, but didn't pay too much attention to it. It's an additional way to better fit clubs. Not only finding the optimal MOI, but to match the balance between the clubhead/shaft throughout your clubs. So your clubs can be MOI matched, but not MBI matched.

The clubmaker has come up with a spreadsheet with a calculator for it. It can be found here:

www.agcpgolf.com/gcv2p5.xls

I'm very interested in this, but I'm sure it will take me a while to figure it out.






3JACK

[golfbaka]

As I've don't have a MOI machine (yet), I've been playing around with this spreadsheet for a while. I look forward very much to your analysis of it.

[Richie3Jack]

What's interesting to me is that before I started to read this yesterday, it came up over on Wishon's forum when I mentioned that I felt I found that while MOI matching and fitting is great, to go above and beyond with clubfitting you have to fit the golfer based on the weight of the main components of the club (shaft, grip, head). And that I found that my irons are best at 2,725 MOI, but with a 50 gram grip, a shaft that weighs about 110-118 grams and more weight in the head.

And that's what MBI is supposed to help with.

I also found it interesting in that it seems to help with distance. I have always had that weird short iron that for some reason I hit shorter than I should. I *think* that it is a MBI issue.

Ought to be interesting.





3JACK

[golfbaka]

I've been messing around with my R11 driver, where its easy to change the weights shafts etc. and the conclusion I've come to is that total club weight is vital to fit for first and foremost.

I was experimenting with a light total club weight but with a MOI that should fit me (irons + 150) but I found the light weight difficult to control and found I needed to increase the MOI to get to wear the club was more comfortable. Which obviously mean't increasing the weight of the club...

My fitter had mentioned to me before that if you have a club that is lighter (too light for you) then your prefered MOI will go up

[Richie3Jack]

Feb 13, 2013 10:21:47 GMT -5 golfbaka said:

My fitter had mentioned to me before that if you have a club that is lighter (too light for you) then your prefered MOI will go up

I guess I don't understand that statement.

If you don't mind, who is your fitter?


Anyway, I agree, total static weight is very important in equipment, yet almost always gets neglected by golfers, fitters, etc.

As I've learned more and more about equipment and clubfitting, the loyalty people have to swingweight matching makes no sense to me.







3JACK

[Richie3Jack]

Interesting. Although I would think that the static weight would be similar. And you have to add a boatload of weight (I would imagine)




3JACK

[golfbaka]

I actually MOIed up a 3 iron in this experiment so I didn't need to add so much weight. I think it might have been the SL so there was a good 25 grams difference.

[Richie3Jack]

I think it depends on the balance point of the shaft. I would imagine that if you go from a DG to a Dynalite and the balance point on the Dynalite is much lower than the DG, then you would not need to add as much weight to the head even though the static weight will be lighter and the the preferred MOI went up.





3JACK

[Richie3Jack]

Some initial thoughts:

- Really a well done Excel Spreadsheet, although the order is a little screwy. I'm an Excel expert (I've taught classes for people at my last 2 jobs on it) and this is very well done. Start with the Instructions tab first, which it opens up to if you download the spreadsheet. Then go to the tabs down to the right (App Notes, Theory, Tools, etc).


- Part of what this is attempting to solve is a common complaint of how the long irons can feel a bit head-light despite being MOI matched. I've never really run into that problem outside of the 3-iron and it's not too different and much better than swingweight matching. In fact, the 4-iron on 2 different MOI matched sets has been the best club in my bag. However, I think the bigger idea is it gives a better idea of how to find the right shaft weight, head weight and grip weight to go along with the MOI matching for the ideal fit.


- Really interesting in Doherty's bag that he uses different shafts throughout his IRON set. It's all SK Fiber graphite models, but some are 95 grams and some are 100 gram models. All in order to get the target Balance Index.

It appears that the shorter irons tend to have the heavier shaft models (9, PW and AW) are likely done to reduce the amount of weight put in the clubhead.

I'll have to fiddle around with this some more.






3JACK

[Richie3Jack]

From what I'm understanding now, the way this works is:

- You have to get MOI matched first.

- Then find the club(s) out of the set that you hit the best. Then you examine that club.

You then have to know the pertinent information like:

Head weight

Tip Weight

Ferrule Weight

Grip weight

Grip cap thickness

Shaft dimensions (i.e. trimmed weight, balance point, MOI of shaft with grip on (no head), etc.


Once you get that information, you can just simply plug it into the spreadsheet and that will calculate the MBI. Once that is done, you can either take your other clubs and re-work them to match the MBI or get new clubs and make them to that MBI.

The problem is that it's obviously a time consuming process. As it mentions on the spreadsheet, it may take too much time if you run an actually clubmaking/clubfitting business.

I'm going to try this out once I work a few kinks out in my swing as I'm looking to getting the 575MMC irons





3JACK

[Richie3Jack]

Small update.

I e-mailed the creator of the excel spreadsheet, Monte Doherty.

He told me that the only way to do MBI with a club you like is to either have all of the data calculated or to disassemble the club.

I can figure out most of it, but I can’t remember how much of a hosel weight I put in my 4-iron and 6-iron. Plus, I don't know what the balance point of the shaft with the grip is (no head attached). So I will have to remove it anyway.

Clubmaker David Hohnke says that you can take your best club and add a little lead tape to the balance point of the club. If you hit it more online, you probably needed a little more weight in the shaft. If you are missing it more to the right, you probably need less weight in the shaft.





3JACK