Top critical review
COMPARING ZEPP 2 GOLF WITH A PROFESSIONAL SWING MONITOR
June 28, 2016
I did an initial review when I first got the Zepp 2; I have since removed that review and downgraded my score based on this more comprehensive evaluation of the Zepp 2. I have now owned my Zepp 2 for about a month. I have compared it to the professional GC2 Launch Monitor while wearing the Zepp 2 during the Launch Monitor session. The results of my evaluation are itemized below.
Before doing this evaluation, I carefully entered all my club specifications including length. I also carefully entered my grip orientation. The instructions indicate this is very important to get results as accurate as possible.
You should know that I am a super-senior golfer who has been playing golf for many years. I have had numerous golf instructors, including the Butch Harmon School of Golf. Naturally, my swing speed has degraded over the years. I also noted in my previous review that I am a Ph.D. in physics, so data is very interesting to me.
I use an iPhone for the app so I cannot answer any questions concerning using the Zepp 2 with an Android based phone.
DO NOT EXPECT ZEPP 2 TO MATCH EXPENSIVE SWING ANALYSIS TECHNOLOGY. However, I do recommend the Zepp 2 if the user understands its limitations.
1. Zepp 2 is an inexpensive alternative to swing analysis.
2. It makes work on the driving range more fun and productive.
3. It contains many useful instruction videos and tips.
4. It allows you to adjust the goals for the five swing metrics. This is a positive since we all do not swing like pros. Nevertheless, the metrics do allow you to work on specific areas of you swing to make improvements.
5. The Zepp 2 technical support team responds quickly to your email questions; however, they are not always accurate in their response. See CONS: Other Issues below.
Swing Speed Accuracy:
1. Zepp 2 is not accurate for shorter clubs. For the SAND WEDGE, it registered 23 mph FASTER than the GC2 Launch Monitor. This is slightly more than a 50% error and therefore not a useful measure of club head speed!
2. The Zepp 2 becomes more accurate as club length increases. For the 6-IRON, Zepp 2 registered 5 to 9 mph FASTER than the GC2. This is only a 13% error for a 6 iron swing speed of 70 mph.
3. For the DRIVER, Zepp 2 registered 2 to 6 mph SLOWER than the GC2. This is only a 9% error for a driver swing speed of 75 mph. Hey, I said I was a super-senior. It starts out being much faster than the GC2 for shorter clubs but crosses over to being slower by the time you get to a driver length. Insufficient time did not allow finding the exact crossover club.
1. The Zepp 2 over-the-top indication is not always born out when directly comparing to the video on the GC2 Launch Monitor. If your over-the-top amount is only a few percent, I would take that with a grain of salt. If it is more than 20% you might want to work on that metric using the instruction videos provided.
2. When charging the Zepp 2, just unplugging the charger and storing away the Zepp 2 will cause it to lose charge within just a few hours. It seems to act as if it remains on. However, if you deliberately turn it on and then turn it off after charging, it will remain at full charge for some time (days). The Zepp 2 technical support team does not seem to be aware of this quirk in the sensor. Perhaps it is just my sensor.
3. The calibration process needs some adjustment to its voice instruction. It is almost impossible to hold it still enough while addressing the ball to get a successful calibration. However, the Zepp website notes that you can simply place it on a flat surface and then initiate the calibration. This results in successful calibration every time. The Zepp 2 app should be updated to give this alternative calibration process.
4. On practice swings without a ball, the maximum club head speed in the metric does not agree with the maximum club head speed in the swing speed graph. See attached pictures. This may be due to the fact that when no contact is made with a ball the software must estimate when the contact would have occurred. Alternatively, it is probably due to the loss of club head speed when an actual ball is contacted due to conservation of momentum and energy. The software must be attempting to estimate this loss of club head speed at impact. I told you I am a physicist. The support team gave an explanation that did not make sense to me. They also gave me a long list of things to do to make it more accurate, all of which I had already done.
5. Zepp 2 does not register club face angle at impact. It seems to me that the sensor algorithm could be monitored to register this metric by assuming the face angle is square at setup. Other inexpensive swing monitors do register face angle; however, the others have their own issues that led me to purchasing the Zepp 2.
6. Zepp 2 does not register launch angle; I would not expect this from such an inexpensive device. It is not a radar launch monitor like Trackman and it is attached to the glove.