2-K Pulley Diameter

[Par71]

From 2-K:

When the Belt starts around the Pulley (Release) its MPH does not change (Constant Hand Speed) but the Clubhead goes into an Angular Motion and its Surface Speed becomes proportional to its: 1). Radius, 2). Belt Speed and 3). Pulley diameter. Increasing the diameter and/or the Belt Speed increases Clubhead MPH and vice versa.

Is this a typo? Why does increasing the Pulley diameter INCREASE Clubhead MPH? Shouldn't the Surface Speed of the Clubhead rather be inversely proportional to the Pulley diameter (the smaller the Pulley, the more Clubhead speed will pick up when the Belt goes around the Pulley) - as in 6-N-0 and 7-18?

Or am I missing something here?

[Daryl]

Appears to be a blunder.

[O.B.Left]

Is that from the 7th? Its not in 2K in my 6th I dont believe. Its an interesting quote.....but

Id say that if you were considering various sizes of pulley wheels and were given a certain rpm for an axel that was driving the pulley wheel (as opposed to belt drive with a given belt speed) , then the larger the diameter the greater the surface speed associated with any given axel rpm. But the endless belt analogy is not so constructed and in terms of CF throwout a larger pulley (earlier Release point) is actually associated with "the slowing effect", 6-C-2-B.

[BerntR]

If you have a an endless belt with a club attached, ref 2-K, the belt will have a constant speed of course, and the club will have the same speed during linear travel and greater speed in the curve. The smaller the pulley is, the more speed the clubhead will pick up.

However, if the belt carried no mass and the system were simply freewheeling, and the only thing that carried mass was the clubhead, the clubhead would have constant speed and the belt would slow down around the corner and pick up speed on it's linear travel.

There is no magic trick here that suddenly increases the clubehad speed. You have to do speed up the club with your hands. So what you're ideally looking for is a pulley size that lets you apply max force for as long as possible. Larger pulley will let you apply power longer, smaller pulley size will probably get you closer to your max power but not let you apply it for very long.

If you swing a shaft without a clubhead you will get max swing speed with a very small pulley. If you swing a very heavy club you will max the speed with a large pulley. How heavy a club feels depends on how strong the golfer is. Therefore I believe that the optimal pulley size is different from golfer to golfer.

[O.B.Left]

If you have a an endless belt with a club attached, ref 2-K, the belt will have a constant speed of course, and the club will have the same speed during linear travel and greater speed in the curve. The smaller the pulley is, the more speed the clubhead will pick up.

However, if the belt carried no mass and the system were simply freewheeling, and the only thing that carried mass was the clubhead, the clubhead would have constant speed and the belt would slow down around the corner and pick up speed on it's linear travel.

There is no magic trick here that suddenly increases the clubehad speed. You have to do speed up the club with your hands. So what you're ideally looking for is a pulley size that lets you apply max force for as long as possible. Larger pulley will let you apply power longer, smaller pulley size will probably get you closer to your max power but not let you apply it for very long.

If you swing a shaft without a clubhead you will get max swing speed with a very small pulley. If you swing a very heavy club you will max the speed with a large pulley. How heavy a club feels depends on how strong the golfer is. Therefore I believe that the optimal pulley size is different from golfer to golfer.

Thanks for this Bernt.

The Endless Belt analogy fascinates me. For me it lies right at the heart of the mechanics of golf, swing DNA, hitting vs swinging, whether we should attempt to look like Hogan or not , how do we best Delay Release if we're a Swinger or if we're a Hitter, why there is no one best way, why some component combinations are detrimental , which pressure points are we employing and why......etc etc.

That one little illustration is beguiling and worthy of its own separate place in the forum maybe.

[miji]

http://perfectgolfswingreview.net/endlessbelt.htm

This writeup shed some new light on the endless belt concept for me. The discussion regarding the incorporation of an initial (assembled) move away from the target and the effect that it has on the diameter of the pulley is very interesting. I've always thought that delaying release was the most logical way to decrease pulley diameter, but it seems like some of the longer hitters might spend the majority of the downswing trying to release (as opposed to retaining)the enormous amount of CF gained ,in large part, by that initial move down and away from the pulley (between 2&3). I also check out some of Sadlowski's swing videos and learned that he needs to make a notable move with his upper body away from the target at release to support the 140mph clubhead speed. It is amazing how he gets that club back up immediately after impact.

[12 piece bucket]

Havent read but will read jeff Mann on endless belt. But those pics with the points plotting the hand path of hogan eldrick and the other dude don't take into account the amount the hips go forward. Clearly the amount the hips go forward and turn are progressively different in that spectrum. That would certainly have an impact on the points plotted. Could it be that the hips are the motor that drive the belt assembly? Obviously the hip motion have a huge huge relationship to the pulley diameter and hand path. Also I think it is clear that Doyle is hanging on and tilting backward and Hogan is slinging the club and moving forward ..... Elidrick is in the middle of the extremes but favoring Doyle......of course this is what the man teaches....max your trigger delay and tilt your teacup. Paper could be an interesting read.

[BerntR]

Shoulders 12 pc, shoulders. But the hips help the shoulders though.

I like the hand path drawings in Jeff's paper. But not the technical explanation.

• Jeff seems to believe that CF creates swing speed.
• He seems to believe that you need a small pulley to release the club (ref Doyle)
• He confuces non automatic release trigger with non automatic release (Doyle).

I don't understand the relevance on the water skier and I certainly disagree that getting from B to C is easy. In fact I'm not sure you can get all the way to C.

[12 piece bucket]

Shoulders 12 pc, shoulders. But the hips help the shoulders though.

I like the hand path drawings in Jeff's paper. But not the technical explanation.

• Jeff seems to believe that CF creates swing speed.
• He seems to believe that you need a small pulley to release the club (ref Doyle)
• He confuces non automatic release trigger with non automatic release (Doyle).

I don't understand the relevance on the water skier and I certainly disagree that getting from B to C is easy. In fact I'm not sure you can get all the way to C.

Agreed . . . . not sure about this but would be interesting to see the relationship of the hips going forward and staying turned and the right shoulder staying "higher" . . . . Hogan stays "closed" for a long time but then he gets considerably more "open" than Eldrick to the ball . . . Eldrick's shoulder with the driver anyway works down more "vertical" than Hogan's . . . whereas Hogan's shoulder is staying high but working OUT to the ball . . . .

[wedgy]

Agreed . . . . not sure about this but would be interesting to see the relationship of the hips going forward and staying turned and the right shoulder staying "higher" . . . . Hogan stays "closed" for a long time but then he gets considerably more "open" than Eldrick to the ball . . . Eldrick's shoulder with the driver anyway works down more "vertical" than Hogan's . . . whereas Hogan's shoulder is staying high but working OUT to the ball . . . .

Wouldn't that( the shoulder movement) affect swing path and ultimately shot shape.