Discussion in 'Tennis Tips/Instruction' started by drakulie, Sep 19, 2006.
Yea! Serve without any balls and see if it would pick up the speed of your racquet hahaha.
Do those radar guns (looks more like a box than a gun that the cops use) in the video measure the speed as the ball goes past it or do those radar guns measure the fastest moving object in front of it that is within range?
It picks up the speed as it is approaching the radar.
so would you not recommend getting the SpeedCheck then? Because I was about to get my hands on one.
This is getting out of hand. Drak's serves are well into the 100MPH range. If you can hit 100+MPH, then post it, with radar. That goes for all of the haters out there. Drak, nice serves man, they look good on the video, I'm glad that someone posted serves with radar. So let's see....70lb kevlar in a PS 85. Try a PDR + with gut at 55lbs and see if you can't hit 150.
Good work man, Peace,
Actually, I thought it was well worth the price I paid ($100 in 1999). Unfortunately I don't have it any more because a friend of mine accidentally left it on top of his car and drove. It was never seen again.
I think anyone who can afford multiple rackets will find it worthwhile, if he is curious about speeds.
I felt it understated speeds, but I am not 100% certain. Consistency is more important than calibration error, and this device IS consistent. You can see that in drakulies videos. It is not like it randomly displays 80 mph or 125 mph.
The only drawback was that it had to be placed in close range unlike the more expensive guns that operate from a distance of 300 feet.
Also it picks up the speed of the first object in its range that moves faster than its cutoff(20 mph or 35 mph depending on the mode you set). This makes it bad for measuring bat or racket speeds, The racket will be continuosly accelerating while being in range the whole time. I am guessing it will show 20 mph regardless of how much faster you swing.
I think the manufacturer should have given this to drakulie for free He will probably generate at least 10 sales for them!
I think that I serve around 115.
Damn, I should thought of that!
Thanks, I appreciate support from some of the non-haters.
Your post is ironic in that I actually posted these because I[/] find it ironic that "everyone" on this board could hit 100 +. Much easier said than done. And although it might not look like it is travleing fast----it is.
Oddly enough I've hit with a Pure Drive a few times, but felt the swingweight was heavier than the 85. It was flying off the strings but absolutely no control.
Yup, that's exactly what I thought. I had seen tons of kids and adults using those racquets so I decided to try it and see what everyone was raving about. So, I take the first 10 swings with the racquet and every ball flies a mile out. I think those racquets suck. Now, what I'd like to see you serve with are some of the old Wilson Hammers. I bet you could serve abou 120 using those things. Hahahaha.
Well most people string incorrectly and use the wrong strings.
IMO you should give the LM Prestige Mid a try, if you want faster and faster serves just add more lead to the tip.
That will increase your speeds
Funny thing is that I have served my best with LMP+ but when I changed to my 13.5oz tnt-90 I did not hit as well but the opponent would say the ball was just a fast but way heavier and sometimes faster.
It did not look that way to me, look like it would be slower and less effective.
This is a really nice service motion.By the way Drac ,what is the string that You use in Your racquet?
Ashaway Kevlar Crossfire II, 16 gauge strung @ 70 lbs. Here is the link:
Have you tried poly/synth gut hybrid string jobs as well?
If so, how did it compare to the kevlar? I never considered
kevlar before. isn't it much stiffer than even poly?
Now you need to lobby Ashaway to give you free string!
A few TT members love you; a lot of them love to hate you; no one can deny you are a minor celebrity around here.
Now that you have shown, with your 100+ mph serve videos, that you can walk some of your mighty talk, your fanbase can only be growing
Thanks for the input! I might be able to get my hands on that particular model, but it's still around $100 and used, which kinda sucks, but I'm a bit strapped for cash and that's my max spending limit for this device.
Yeah no problem. I find it ironic as well that everyone here can serve 100+. Hence my call for video with radar to anyone who thinks they can (and who consequently says: "those are 100MPH??? Mine must be 246MPH then.")
By the way, I can't control those damn pure drives either...
So if I beat Drak, can I be a minor celebrity too?
I agree, but at the same time you have to appreciate that not everyone has access to or is willing to purchase a radar gun simply to prove a point to someone he doesn't even know over the net.
A) you look like a doosh (lol jk)
B) Great videos and pictures.. someone really like their serve
First you have get some skillz, which you admit to not possessing.
That would probably still leave you short of the women, the cars and the charisma
Yeah, I was playing with that combination immediately before the switch to Kevlar. It was fairly similar, but not as much feel (at least for me), and had a little more pop.
The way I started playing with kevlar was through a "freak accident'. I was playing in a tournament and my strings broke while I was warming up. I had a second racquet so I started warming up with the second racquet. Since I knew the director I asked him if he could string my racquet, and he agreed but told me he only had a Kevlar hybrid. I had never tried Kevlar but told him fine (beggars can't be choosers .
Anway, I told him to string the racquet at 70. He freaked out but agreed as long as he could string the crosses a little looser.
I haven't looked back since. Only change is that I string mains and crosses at 70. They are a little stiff but I feel like I get awesome feedback on all the strokes, especially the volleys.
Too funny! Goes to show you some of us "old farts" could still swing a dinosaur like the PS 85 and still get some fairly decent results.
Maybe I'll try it out. 70 seems high! I like the poly /synth gut hybrid
(at about 60lbs) but what happens is that after only a few times of playing
it begins to feel a little dead.
that serve didnt look soo fast, looks kinda like mine and i dont think mine is that fast
For the record, the few times no skillz and I have played everyone knows him. he is like a social butterfly or politician. I feel like a leper. LOL
Just Kidding No Skillz
Silentgunz, have you seen these?
how do you like that radar gun?
seems like it would be fun to get!
Where did you get it and how much?
You can get a very good estimate(may be as good this radar gun) of your serve speed if you can step through the video frame by frame and count them. Each frame is 1/30th of a second.
Because the ball slows down in the air and after the bounce, and the amount it slows is different at different speds, converting the frames to a speed can be tricky.
But a book I have, The Physics and Technology of Tennis by Howard Brody et al, says that a
102 mph serve takes .71 sec(21.3 frames),
110 mph serve takes .65 sec(19.5 frames),
120 mph serve takes .59 sec(17.7 frames),
to get to the receiver's baseline.
These numbers are for fairly deep serves down the middle.
You will need a side view where you can see the ball being struck as well as the ball passing the opposite baseline.
Nice MAn. I am not doubting you. You have clear evidence.
my fastest is 104mph and mine seems alot faster than that !
estimates are just that though....estimates. And that also becomes a problem because as many have pointed out, the quality of videos are pretty low which makes it very difficult to come up with a decent estimate. I'm not doubting that your method is the best alternative given what we have to work with, but in the end, a radar gun (a good one, anyway), is the only way to know for sure.
Well, you said you might not be able to afford a radar gun, and I gave you a sure way of estimating your serve within 5 mph with equipment you already have. Most people can't guess their own serve speeds within 20 mph.
I think you have too much faith in a low end radar gun if you think you will "know for sure" just because it flashes a number at you. As has been mentioned already, there are at least two sources of errors in the radar. It won't get the right speed unless the ball is coming towards it, and it only picks up the speed when the ball enters its range, by which time the ball has slowed down. Even the fancy Radar guns at US open some times pick up bad speeds or no speeds and they don't display a speed.
I tried this method today after my earlier post. I had no problem seeing the ball in the frames, though it is often a streak of yellow. The fastest of those I looked at was about 90, and the slowest about 70. The numbers are pretty reasonable for my serve.
nice. can you give estimates to some of the serves posted in this forum? if it's too time consuming, n/m.
I'm still gonna try to buy that low-end radar gun (if I can) since I'm not spending $800+ to get a higher end one.
yeah, it is pretty interesting using it to hit a bucket of balls, checking the speed on the topspin, kick, slice, etc.
I got it on the interenet. I put a link in one of the posts.
Thanks, glad you like it. Hopefully it will give people an understanding that you don't really have to swing "hard", rather with good technique you get decent results.
I'm starting to figure that out for myself too. Even though it doesn't feel like I'm hitting with much pace, it seems opponents are having a much harder time returning my serves (if I can actually get them in). My serves probably aren't as fast as they used to be, but they're kicking up like crazy now and forcing quite a few errors.
Yeah, the more spin you put on a first serve without losing pase the better off you will be in the end. And again, you don't have to muscle the ball or be a power lifter. I'm 5'9" and weigh about 165-168. I always advocate good technique and placement. The pace will come the better and smother you get.
No because as far as I know, Youtube doesn't let you step frame by frame.
Does your book give you and estimate on how much the ball will slow per foot before the bounce? Assume no wind and a no angle.
I would add that having a hefty racquet has a lot to do with it also. You can swing really fast with a low inertia racquet and it still won't go any faster than if you swung relatively slow but with a heavy racquet.
Dunno if this is what you're looking for Mike, but according to this experiment: http://wings.avkids.com/Tennis/Project/speed-02.html , serves slow down by more than 25% (at least Pete's serves anyway) before the bounce.
No, but "per foot" won't make sense because the it will slow down more in the first foot than in the second foot, and so on.
"drag" force on the ball is propotional to the square of the ball speed.
The faster serves will be slowed by a greater percentage before the bounce. I am at work and the book is at home, but boojay's figure of 25% seems about right for a 120mph serve. There another big change at the bounce and then some more in the air after the bounce. Ultimately the 120mph serve ends up at 55mph when it is returned. That is an overall slowing of 54%.
A 90 mph serve will be slowed by something less than 54%.
i forgot to post the link and edited it AFTER maverick posted, and he was right on the money
Maverick, just to make sure I am following you:
A slower hit ball slows down less than a faster hit ball? Is that correct?
Ineteresting, any reason for this?
There is a Physics explanation for this.
The change is speed(deceleration) is proprotional to Force and the force in this case is the drag force from the air. The "drag" force is prorportional to the square of the speed.
This same drag force applies to cars as well. It is much more fuel efficient to drive at 55 mph than 85 mph.
Basically, when the ball is going faster it has more drag. Therefore it slows down faster at those higher speeds, once it reaches the other serves speed (down to 90 mph from 120mph), it slows at the same rate.
Edit: Good analogy with the cars, maverick, although most people still don't seem to heed that rule. I hadn't refreshed to see your explanation.
When tour players inspect balls before serving, they are looking for balls with the least fraying of the fuzz. A smooth ball will have a much smaller drag coefficient, and therefore will be slowed less by the air at any speed.
What about if they want to hit a giganto kick serve? I would suppose that they go for the ultra frayed balls.
I actually look for less frayed balls when I want to hit a big kick serve. I just figure you get a better bounce with a less frayed ball.
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