Distance issues

[Chmiller]

I know this is a perennial topic. I've read all the advice but still having issues. One thing I just figured out is that changing golf balls makes a huge difference. I went from a Prov1 with a good dark line marked on it to a Bridgestone. 20 yards difference with an 8 iron. Switched back, right back to 20 plus yards short. I hit many shots with each so it's not a small sample.

The remaining problem I'm having is that even when the unit is reading the 8 iron well the 6 iron is way short. Only about 10 yards longer than the 8 iron and a good 10 to 15 yards short of what I average on the course. I use a Shotscope watch so I really know my distances. It's not indoor swing syndrome because I'm getting good distances with the 8 iron.

Any advice would be appreciated.

[SkyTrak_Jordan]

Hello Chmiller. - Make sure your golf balls are up to date. Switching the old ones out every month will help maintain your averages. In Session Settings, make sure the elevation and temperature match the environment you normally play in.

[Chmiller]

Should I always use new golf balls? Does it help to put a line or other mark on the ball? Why would the distances be off only for longer clubs. Haven't really tested hybrids or woods yet.

[bubbtubbs]

Because balls lose their elasticity over time and don't transfer energy as efficiently.

The longer clubs generate more speed and compress the ball more so you'll see a more drastic drop-off in ball speed and distance at the top of the bag if you're hitting beat-up ones.

[Chmiller]

How many strikes would you expect a ball to last? I am getting VERY frustrated at the short distances. I was hitting a 7 iron absolutely flush as hard as I can and going 130 yards. Should be 150 for an average golf course shot, not swinging for the fences. A crushed 5 iron was going only 145 to 150. Drives me nuts. I’ll try a new ball later today and see if that changes things. If so, I”m going to go through a lot of golf balls this winter! They seem to be shot after a day of practice.

[bubbtubbs]

Depends on a bunch of factors, mainly swing speed. I can get 600 or so hits out of a pro V1 if I stick to mid and short irons. Wedges cut up the cover a fair bit with repeated hits so I change the ball out sooner if I'm hitting a lot of pitch or full swing wedge shots. With driver, they only last about 200-300 hits.

There's an average in there somewhere for mixed club practice or sim play but no idea what it might be. I know my smash factor averages for each club and if the smash is much lower than expected and it wasn't a thin or flippy hit (high VLA) then the ball needs to be changed.

[Ronsc1985]

All camera launch monitors simply use the ball flight parameters to compute distance

You are concentrating on distance without paying attention to ball speed, launch angle and spin rate and azimuth. If you would keep track of those parameters and compare them you might figure out what is going on.

In round numbers your ball speed should be separated by 4 mph or so from club to adjacent numbered club. The launch angle differential is roughly equal to the loft differential between clubs. Your spin should be increasing as the loft increases club to club. How much has to do with club head speed.

[Chmiller]

I do monitor launch and spin. I check the shot optimizer and my parameters are all in the green for most shots.

[wbond]

Do you have the ability to take it to a range? if so it will quickly rule out an issue with the device. Take a couple spare balls you don't mind donating, laser a target about 150 out and see what it shows for shape and distance.

[Chmiller]

I will try taking it to the range next time I go. I have a range nearby that has trackman range so I can get ball data on every shot. Launch angle, carry, total distance, etc. It's my data from many range sessions plus my Shotscope watch that tells me the Skytrak is reading way short.

[Chmiller]

BTW I tried several different golf balls yesterday and they showed only small differences between a new ball and well used but not destroyed ones. I'm getting to the point where I'm just going to forget about accurate distances. At least I can see ball flights and direction. Still pretty frustrating.

[Ronsc1985]

I do monitor launch and spin. I check the shot optimizer and my parameters are all in the green for most shots.

You say your 8 iron goes the correct distance but the 6 iron does not. The LM uses the same ball ballistics calculation for both. Compare the parameters for the 8 iron with the 6 iron. There is something out of whack with your 6 iron parameters. Post the numbers for both and try using a ball ballistics calculator like Trajectoware Drive which is a free download.here https://en.freedownloadmanager.org/W...rive-FREE.html or at Dave Tuttleman's web site

[wbond]

Data from there is irrelevant in regards to you using a different piece of hardware in a completely different setting. If you actually want to prove to yourself the device is inaccurate, then taking it outdoors and hitting a few good balls (not range balls) to a lasered target is the only way.

I will try taking it to the range next time I go. I have a range nearby that has trackman range so I can get ball data on every shot. Launch angle, carry, total distance, etc. It's my data from many range sessions plus my Shotscope watch that tells me the Skytrak is reading way short.

[Chmiller]

A little bit of insight from today's session. 9 iron went about the right distance but as soon as I switched to the 7 iron it barely went past the 9. I went on to 5 iron and 5 hybrid. They went farther but still well short of normal, about 20 yards. When I looked at the spin numbers I could see immediately that the numbers for the wedge and 9 iron are crazy low. This would account for the more normal distance for the 9 iron. There's no way I was spinning a 9 iron at 2900 rpms. See attached screen shot. The 7 and 5 iron and hybrid are a bit low also but closer.

There is definitely an issue with reading spin. I'd like to check the spin numbers on previous sessions but my Skytrak software is not uploading or downloading shot histories recently. Tech support is looking into it.

I faced the logos toward the unit but I did not put any additional markings on the ball. I often put a good dark line on the ball but didn't this time. I changed balls several times and saw no substantial change. Do you guys add markings to the ball to help with spin readings?

Ultimately I'm getting used to the idea that I can't get accurate distances from the unit. I'm glad I can see ball flights. I can easily tell when I strike the ball well. I can usually predict distance direction and curvature when I strike the ball. But it shouldn't be so hard to get reasonable distances.

Next stop is the range but right now it's snowing here. The range I use is covered and somewhat heated but I'd like to wait for a decent day.

[Ronsc1985]

A little bit of insight from today's session. 9 iron went about the right distance but as soon as I switched to the 7 iron it barely went past the 9. I went on to 5 iron and 5 hybrid. They went farther but still well short of normal, about 20 yards. When I looked at the spin numbers I could see immediately that the numbers for the wedge and 9 iron are crazy low. This would account for the more normal distance for the 9 iron. There's no way I was spinning a 9 iron at 2900 rpms. See attached screen shot. The 7 and 5 iron and hybrid are a bit low also but closer.

There is definitely an issue with reading spin. I'd like to check the spin numbers on previous sessions but my Skytrak software is not uploading or downloading shot histories recently. Tech support is looking into it.

I faced the logos toward the unit but I did not put any additional markings on the ball. I often put a good dark line on the ball but didn't this time. I changed balls several times and saw no substantial change. Do you guys add markings to the ball to help with spin readings?

Ultimately I'm getting used to the idea that I can't get accurate distances from the unit. I'm glad I can see ball flights. I can easily tell when I strike the ball well. I can usually predict distance direction and curvature when I strike the ball. But it shouldn't be so hard to get reasonable distances.

Next stop is the range but right now it's snowing here. The range I use is covered and somewhat heated but I'd like to wait for a decent day.

For the ball parameters you posted the flight numbers are correct. I never look at flight plus roll since the roll is a guess at best. I would also note the differentials between clubs for launch angle appears to be off. In general they should change by about the difference in club loft for closely adjacent club numbers, Since a whole lot of people seem to get correct flight numbers on their Skytrak your problems are not inherent to the machine design. I'd try reloading the LM firmware if this is possible or send it back if you can.

[preludesam]

It’s unfortunate but I don’t see anything wrong with this data. I know you are potentially seeing something slightly different on the course but we have to remember where your ball ends up and the distance it carried are two totally different things.

Carry distance is basically decided by three parameters. Ball Speed, Vertical Launch Angle, and Spin.

It would be one thing if the Club Speed was off compared to Ball Speed but you’re getting pretty a good Smash Factor. You’re Ball Speed just isn’t high enough for that Launch Angle and the Ball Speed is not increasing enough for the lower lofted clubs causing very close carry distances.

Not sure about your age and strength ability but if I was fitting you for clubs you would be in an 11 wood through 5 wood. It would help you getting the ball in the air.

[Mirek_62]

To check the distances of individual shots you can use this .

https://trajectory.flightscope.com

You can also find out what is the optimal launch angle of the shot for your ball speed.

For all LM's ALWAYS follow the CARRY distance only.

[Chmiller]

A lot of good points above but I have to say I’m not really convinced these distances are correct. In the end, I’ll test it at the range to see but this is why I’m skeptical: I understand that roll out distances are approximate, but then so are all of the distances. They are extrapolated from a few inches of data so are all approximations. The distance numbers I have that are most reliable are season long averages of distances from the golf course from my Shotscope watch. I don’t play on hard or fast fairways and Shotscope discounts especially long and short shots to get their Performance Average, which is what I’’m using. They only show total distance so I don’t have carry numbers. I also have data from many range sessions with Trackman range, which does measure carry.

My season long performance average for my 6 iron is 157 yards total. On the SkyTrak I can typically only barely reach 150 yards most days on my best shots. I believe that those especially strong shots would go well above my performance average, maybe 170 yards again based on shots I see on the course. I am swinging out of my shoes to get the distances I’m getting on SkyTrak and I’m absolutely crushing the ball on enough shots that I know I’m reaching my absolute limit in distance on the Skytrak. I don’t swing like that on the course so I think the performance average is a conservative measure of my typical decent shot. It’s not my best of the day. I will say that despite the distances, my ball striking has improved a lot over the last few weeks.

It is true that my swing and ball speeds are not particularly high. I’m 67 years old and I’m relatively long for my age, but those numbers are about right. I do see compression of distances when I get to the 5 iron and beyond due to the lack of ball speed and the consequent reduction of spin with low lofted clubs. I wouldn’t be surprised if the launch numbers are pretty close. Without the speed to generate spin my launch and peak heights get low with the longer irons. However, my gapping is really good at least through the 6 iron and actually all the way up to the Driver (again from the Shotscope watch.) I usually switch to hybrids at the 5 iron and then to a 7 wood and 3 wood, which fly higher and carry better than the hybrids.

I did do another session last night with a dark line on the ball and the spin numbers I got were much more consistent than earlier. I think I’ll use the line in the future. Anyway, I’ll stop complaining here until I’ve tested at the range. I will eat my words if I’m wrong, which will be quite a meal based on all my posting here! I will say though that even if the Skytrak is measuring correctly, it’s not correlating to what I see in the real world and is of no real use in measuring distance performance for gapping or anything that has to do with distance. I am getting shot shape and direction, which is useful for practicing but it’s not what I was expecting when I spent this much on the unit.

[jpotas]

Edited to make a separate post,

[Mirek_62]

To calculate the carry distance, a quite complex equation is used, which is also verified by knowledge of aerodynamics and airflow. These calculations come from university professors and NASA personnel. They are by no means estimates or mere extrapolations.
Skytrak is a photometric system, and all it really needs to calculate is a short segment of ball flight where it takes two photo images and uses them to calculate everything needed to calculate carry distance (i.e. ball speed, launch angle and backspin).