Is there any way to calculate arrow speed without a chro?

I am shooting a Bear Takedown 50# at 28" drawing 28". Shooting a 29" XX75 500 arrow, fletched w/ 3 - 4" parabolic feathers, 125gr ft's or snuffer 2 blade broad heads. Split fingers w/ a tab, off the shelf.

Thx PeteA

Nope.

Actually, I guess there is, but you'll need two really good friends, 2 very accurate stopwatches, about 50yards of flat land & lots & lots of time to shoot a lot of arrows & take an average.

Or don't bother.

Are you happy with how the bow shoots?
Are you happy with your arrow's trajectory at hunting distance?

If so, don't worry. The worst thing I've ever done was to chrono a bow that I thought was shooting about 170fps. Turned out to be just over 140. Sold that bow the very next day because I thought I 'needed' a faster bow & I've regretted it ever since.

Here's my guess.

Capture a shot of 100 feet on video, maybe using a cellphone.  Upload that to your computer using Bluetooth.  Import the video into an editing program like iMovie.  You can use the timeline to get the time that elapses from release to impact.  Divide 100 by time of the arrow's travel.  If it takes 0.5 seconds to travel 100 feet, your arrow is traveling 200 feet per second.

Find your point-on, with your form, that will give you a clos idea.  Anyway, numbers can vary quite a lot from cronograph to cronograph if they are not calibrated regularly.  I don't worry about numbers other than how my bow performs with my form at a certain distance.

Yes, high speed camera with a large grid/scale in the backround. (they do it on Myth Busters all the time)  If you don't have the high tech equipment,  it would be cheaper to go pick up a chrono anyway.

Well there is a way that involves shooting two groups of arrows at two different distances but not changing your aiming point, You then measure the gap between the centre of the groups and look up on  a table to find the approximate speed.
This method is obviously not perfect and loose groups will not help in the accuracy of the test. Another problem is that the only table I have found on the net starts at 220 fps.... maybe some maths guru can work out the lower speeds from this table?
Me, after using this method for a while I bought a chronograph some 15 years ago and it was well worth the investment.

here is a link with the table I am talking about:
  Arrow drop and speed

Anytime I shoot mine and there is no chronograph around,  I always shoot over 200fps.

That's a fact
ChuckC

most archery shops have a chronograph.

If ya shoot dark feathers, your bow will seem to be faster than shooting bright feathers.   :rolleyes:

* Using trad gear you might want to let go of the speed thing. But... That's just me.    

... mike ...

mcgroundstalker, well there might be another bow out there a few fps faster 8^).   I'm quite contented to know that my bow shoots plenty fast without knowing numbers.

I just bought a chrono for myself,it would be hard.I paid $80 for mine,I guess you could but it would take alot of calculations with an accurate way of timing an arrow between two points.Get a chrono,shoot through it and it will give you the speed instantly.

I bought a chrono  two year's ago best thing I could have done to tune my bows, you can find the sweet spots with it, (brace height) check your release,the differnce between feathers or vanes, arrow weights, and rest set up. I think I paid about $130.00 for it to my door.

Get your mate in a really quick car or on a really quick bike, have him gun the engine, and drop the clutch just as you drop the string; get him to keep up with the arrow and take a glance at his speedo.

Ben,  speedo is something quite different up here;  and I would want to see any of my "mates" in one 8^).

I shot one of my bows through a chrono once and was so disappointed in the number I never check again. I don't care how fast a bow shoots. All I care is how well I can shoot it.

Yeah, you shoot at 60yds. Just start counting upon release of the string and then times the number of seconds it takes for the arrow to hit the target by the number of days in the month, divide it by the moon phase, and there you have it!

I sure wish I could remember the formula, I have done it and it's pretty close. The part I don't remember is how many inches different is how many FPS.

   I used a match stick as a sight and adjusted to hit at 20 yards. When that is dialed in, you move back to 30 yards and use the same 20 yard pin. Then you measure the difference in inches.

   Since I can't remember the formula, this is all worthless. Like the rest of my memory also. What were we talking about!

You could calculate the arrow speed very accurately using calculus, if you shoot the arrow from a known distance with the arrow exactly level at the time it was shot.  Measure the drop (e.g. if the arrow was shot from a height of 5' and impacted the target at 2', the drop would be 3') and you have all the factors you need to calculate average velocity.  The nice thing is that the weight of the arrow doesn't matter, just the velocity, since under Newton's law, heavy objects drop at the same rate as light objects.

Course, it probably wasn't average velocity you wanted, was it?  Can't help you with muzzle velocity, unless the target is really close to the bow, and then the drop is likely to be too small to accurately measure.

Funny Z-Man. Sometimes I feel like a pencil with just the eraser part.

Arrow speed is relative. Sure would hate to find out mine are slower than I think.