Why different lofts for irons? - physics/science questions

[Alohaed]

I finally learned how to "hit down" on the ball, taking a divot. I also am under the impression that I am now compressing the ball. My iron shots are now accurate, straight and getting farther than I've ever hit them. My question is... if compressing the ball is what is sending the ball in the air, and swing speed helps with distance, how is the different lofts then affecting distance?

[double_j]

It's not really rocket science. Throw a ball at a vertical wall and see how it bounces off. Now repeat the same exercise with a surface that's angled upward and watch the change in trajectory.

PS - I believe the compression of the ball affects overall momentum. The loft of the club (and the resulting backspin) play larger roles in determining general shot trajectory.

[Paradox]

If all your irons were the same loft, every shot you hit would be pretty much the same distance if you put the same swing on the ball.

Irons are designed with different lofts so that you can essentially make the same swing and hit the ball different distances(not the only reason, but A reason). The rate of backspin will be higher with more loft, as well.

[out_in_30]

If all your irons were the same loft, every shot you hit would be pretty much the same distance if you put the same swing on the ball.

well if your irons were same loft and different length then the distances would be different. length also plays a role in how far a ball goes. but yea.. to the OP.. the overall concept of lofts is pretty basic. double J made a pretty good analogy on how it works.. hitting down on the ball doesnt have anything to do with the loft on the club. higher loft, higher trajectory and shorter distance.

[zeg]

To add to what's already been said, the primary goal is to give you different distances. If you ignore spin and air resistance (which you can't do, but it illustrates the point; all the angles I'll quote are wrong as a result of this extremely faulty assumption), then for a fixed length club, a 45 degree loft at impact will give you the longest flight. At lower lofts, the ball will fly faster, but lower, and hit down early, at higher lofts, it'll fly higher and for a longer time, but travel less distance as well.

When you add in the air resistance and spin, things obviously change. The backspin adds lift, so you get longer shots with much lower lofts since the flight is no longer ballistic. But it's still the same principle, as you increase loft, you will give the ball more upward velocity and it will not go as far. Add to that the shortened shafts, and now the ball launch speed is lower as well, also adjusting the distance.

Having a choice of trajectory for the same distance is also important, which is why you see some overlap between lofts for high-numbered woods and low-numbered irons.

[David K]

If you ignore spin and air resistance (which you can't do, but it illustrates the point; all the angles I'll quote are wrong as a result of this extremely faulty assumption), then for a fixed length club, a 45 degree loft at impact will give you the longest flight. At lower lofts, the ball will fly faster, but lower, and hit down early, at higher lofts, it'll fly higher and for a longer time, but travel less distance as well.

Since "physics/science" is also included in the title I would just like to ask a question you might know. If the club has 45° of loft at impact will the launch angle of the ball be 45°? I guess how the ball compresses on the face of the club has a lot to do with it. I've just been curious about that but never had the chance to mess with a shot tracker to find out.

With less loft your imparting more direct energy into the ball to get higher ball speeds. Higher ball speed = more distance. When you have more loft the energy is being directed upwards instead of outwards which results in lower ball speed, higher flight and less distance. To get optimum distance with something like a driver you would need to have the right balance between trajectory and ball speed for your swing speed. Same goes for irons I would think. My Cobra FP II irons have 2 degrees less loft than most clubs. I have a high ball flight compared to most people so it works out perfectly for me. I do think having irons with less loft lets manufactures claim their irons are longer than others as a selling point though. Different lofted irons have the same purpose as different lofted driver in my opinion. You need to get whatever works with your ball flight, power or personal preference.