mini CHRONO experiment part 2

[Hoytail Hunter]

PART 1 if interested
http://www.huntingnet.com/forum/tm.aspx?m=2026213&mpage=1&key=&#202629 2

PART 2
The bow:

Vectrix, 26" draw, 60lbs, 5/16 g5 meta peep (with a cut up upperhalf of the old 1/4 inch peep used asa tube aligner), ripcord drop away, 326 grain CX maxima 3-D selects, string loop, and nothing else on the string

TEST 1
65% let-off = 252 fps

TEST 2
75% let-off = 254 fps

TEST 3
80% let-off = 256 fps

So to summarize, taking the 1/4 inch peep off and replacing it with a g5 and aligner,plus removing 3 brass nocksnetted a gain of4 fps. Notice from test one of the previous thread that 3 brass nocks and a big honkin' 1/4 inch tube style peep tripped the chrono at 252.Keep in mind the previous tests were all done at 80% let-off. This time they were done at 3 different let-offs so the only one really relevant for comparison is test 3 of this thread.

Considering that each brass nock weighs about 3-4 grains and half the 1/4" peep that I cut off is probably10 grains, this means I gained 4 fps for a stringweight loss of about 20 grains.

[TFOX]

You might want to add that with this style cam,the 65% letoff is actually a shorter draw than the 80%.that is the reason for the higher speeds at 80% letoff.

[Hoytail Hunter]

Something else I learned while shooting through the chrono too:

You have to stand back far enough so that the arrow doesn't trip the sensors of the chrono before it leaves your bow. If you don't it'll read about 10fps slower than the speed of the arrow when it actually leaves the bow. I suppose you can think of it in terms that the power stroke hasn't completed yet and the chrono is already capturing the speed.