How accurate is the speed on monitor? (video included)

[KYDave]

One of the centers I practice has the newer AMF with the speed on the monitor. I like it because I can see how consistent I am and can practice speeding up or slowing down. But how accurate are they? It usually shows about 14.5ish on my normal shot. I feel like it is a little faster than that, but people have told me that is probably mid 15 out of my hand so pretty normal.
I'll include a video for people that know more about what they are looking at than I do. I found a vid that is lane level and playing fairly tight line so to take hooking half the lane out of the equation.
Note: The color dots I use to help me see ball motion/transistion easier. The commentary are from a group of kids that came over to watch me bowl for a bit. It wasn't that busy and bouncing the 5 pin off the rack a few times was noisy enough for them to come see what was going on lol.

http://vid1029.photobucket.com/albums/y354/kjmike95/pics/speed%20test_zpsqgjpnqb2.mp4

[bowl1820]

The speed monitors are notorious for being inaccurate at a lot of places.

When their working they are pretty accurate for the speed at the pins (For your "off hand" speed the rule of thumb is to add about 3 mph to the monitor speed.).

The thing to really use them for is to watch for changes in speed. Even if they don't tell the correct speed, they will still show you if your varying your speed from shot to shot.

[bowl1820]

Using my ball speed app , your video and assuming a 15lb ball, I'm getting :

release velocity:19.7mph
pin contact velocity: 16.4mph

average speed: 18.6 mph

So 16.4 - 14.5 so it might be off 1.9 mph at most

With more shots, we might get a more accurate estimate. But would need to see the moment of release better to time it better.

[KYDave]

Thanks for the reply!
So even if the speed itself is wrong, it is consistently wrong. That's good to know. So speed is off, the people that told me 1mph difference from hand to pins were wrong, but atleast when I'm practicing speed adjustment the variance is right.
And this app, what is it called? I recently got the PinPal app and love it. Just wish there was a spot to make notes on the shots.

[bowl1820]

The App I have is for a IPhone/Ipad it's .99¢ app called "Bowling ball Speed" (aka:Bowl Speed) you need someone to work it while you bowl. But it's surprisingly accurate.

It gives you release speed, pin contact speed and impact momentum.

https://itunes.apple.com/us/app/bowling-ball-speed-calculate/id538355430?mt=8

I've used it with videos and it's been pretty accurate.

http://a2.mzstatic.com/us/r30/Purple6/v4/68/34/83/683483f6-7ef5-41de-b704-94a22c44f703/screen568x568.jpeg

[KYDave]

Android user, I'll have to see if it is on that platform.

I found another vid that is lane level with release. This is several months ago because I was using the mongoose to help train my wrist and I was still coming around the ball pretty bad, and turning real early. Yet another thing that video has helped me improve! This shot I have notes of and know the speed is different than the 1st vid. Curious to if the differential is the same.
Thanks!

http://vid1029.photobucket.com/albums/y354/kjmike95/pics/speed2_zpss9b7cjhm.mp4

[foreverincamo]

Where I bowl it seems like the ball shape changes how it reads the speed. It only reads at the pins, and an arcing hook reads lower than the hockey stick pocket entry.

[bowl1820]

Okay, I tried it with that video several times so I think I have a good average.

release velocity:18.5mph
pin contact velocity: 14.9mph
average speed: 16.6 mph

[bowl1820]

Where I bowl it seems like the ball shape changes how it reads the speed. It only reads at the pins, and an arcing hook reads lower than the hockey stick pocket entry.


Yes, it depends on the angle the ball goes through the sensors. A ball going through at a angle takes slightly longer going through the sensors and shows a slightly slower speed the bigger the angle the slower the speed.

A ball going straight down the lane through the sensors will show the most accurate speed (Like a plastic ball thrown straight down the lane).

[KYDave]

Okay, I tried it with that video several times so I think I have a good average.

release velocity:18.5mph
pin contact velocity: 14.9mph
average speed: 16.6 mph

Interesting. Notes say 13.8 Maybe lane to lane is a little different as well. I had expected maybe it to be a little more linear. Either way, as long as it is consistent (right or wrong) I can atleast count on that. Thanks again for your help.

[bowl1820]

Interesting. Notes say 13.8 Maybe lane to lane is a little different as well. I had expected maybe it to be a little more linear. Either way, as long as it is consistent (right or wrong) I can atleast count on that. Thanks again for your help.

Well 13.8 vs 14.9 that's only about a 1 mph difference. Depending on the +/- margin of error that's pretty close.

Take 13.8 +3mph gives 16.8mph compared that with the average speed: 16.6 mph I had.

That's less than .25 mph difference there.