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View Full Version : Low Power New Cheetah



jumptolive
01-02-2009, 07:35 PM
I just got my new Cheetah today. 08 Model, 65#, 28" Draw, 80% Let off. I was expecting this bow to shoot somewhere around 270 fps with KE in the 60 to 65 ft lbs. I have custom arrows with a total mass of 400 Grains. I know these arrows are a little heavy but not that heavy. The Chronograph report shows this bow shooting a mere 240 fps and 51.6 ft lbs in KE. This seems real low to me with this set up. Am I missing something?

razorjack
01-03-2009, 06:18 AM
That seems slow,i would hope it would be in the 270's+,i have a similiar setup and it seems pretty fast allthough i have never chroned mine.
That chrono must be off,with a bow that shoots 320ibo i would expect a lot more speed.

bfisher
01-03-2009, 09:03 AM
We get a lot of posts saying the same thing. I haven't shot a bow with the MPro cam on it so can't really say what is possible. However, your arrow is 75 grains over what IBO specs might call for so that would account for 20-25 fps which would put it at 260 fps or so.

Add to that arrow weight is anything on the string, which drags down the speed. I expect to have my Moab in a few weeks so I'll play with it and try to get some ide of what is possible with the bow. I am getting this for a hunting bow and don't consider speed much of a priority for hunting distances, but I'll still work with the bow and see what it's capable of.

Just as a matter for future reference, if you want speed then you need to look at one of the bows with Cat cams on it. For comparison, I'm shooting a FireCat at 26.5" draw and 45#, 267 gr arrow (6 gr/lb) and it's doing 278 fps. And I haven't tweaked the bow yet to see if I can get more.

jumptolive
01-03-2009, 08:47 PM
I am really not so hung up on the speed as i am the total performance. When ordering the bow and doing all the reasearch I really thought the bow would shoot in the 270 fps range with 65 ft lbs or so of KE. I feel the KE is the more important part of the equation but speed can be an issue at the longer ranges as well. All the techs i spoke with, the forums, calculators, etc. pointed to the bow performing in that range. So for it to chronograph so much lower i feel I may have a problem with the bow that is under the surface. Even with the 400 grain arrows I should be getting 260 fps and much better KE. There just has to be something in the set up and tuning that I am missing?

jumptolive
01-03-2009, 08:56 PM
Based on this calculator, http://www.bucklemke.com/ke/ke.php , I would have to have 100 Grains of stuff on my string to make the bow shoot at such low numbers. I don't know what the stuff weighs but all i have is a Knock point, String Loop and 2 Bowjax silencers. Other than that the string does have serving at the Cam, Wheel, and Knock Point. I also switched out the cable slide for a Teflon Model. I was told that String Serving does not affect power? :confused:

razorjack
01-03-2009, 09:59 PM
Based on this calculator, http://www.bucklemke.com/ke/ke.php , I would have to have 100 Grains of stuff on my string to make the bow shoot at such low numbers. I don't know what the stuff weighs but all i have is a Knock point, String Loop and 2 Bowjax silencers. Other than that the string does have serving at the Cam, Wheel, and Knock Point. I also switched out the cable slide for a Teflon Model. I was told that String Serving does not affect power? :confused:

What about your peep sight,do you use a tube and peep,that may make a difference...........

jumptolive
01-04-2009, 07:46 AM
Yes RAD true peep

razorjack
01-04-2009, 12:19 PM
Yes RAD true peep

Ive heard those can rob up too 15fps add that to the equation and things tend to get slower.But still i think you should have a quicker chrono speed.
Also you might want to check your ata length for string stretch,that can also heart your bows performance.
Food for thought,on another forum their is a person that did a little cutom work on his cheetah and he says he got 326 fps through the chrono,so this bow is capable of being in a class of it's own as a speed bow,we'll see what bfisher findings are.

bfisher
01-04-2009, 04:17 PM
Hey Jack, where did you see that thread where the guy is getting 326. I'd really like to see that---first hand. Sounds like the guy must be shooting 70# and 200 grain arrows. Smething smells fishy to me about that one.

jumptolive, you aren't a skydiver by any chance are you? Your name says something to that effect.

I'd like to be of more help with your bow issue, but until I get mine and work with it first-hand I'd rather not speculate on too much. But as to when I'll have any info is up to Martin. I honestly don't expect my bow till about the end of the month. And mine is a Moab so it is slightly different.

razorjack
01-04-2009, 06:26 PM
Hey Jack, where did you see that thread where the guy is getting 326

He's a member over on bowcountry,Hoosierdaddy,when i got mine i talked to him about his and he said he did some limb pocket stuff,shorter strings and cables,also the cam would be in a modified position to get all that speed.
I see you over thier too,anyway pm him he'll tell ya about it.

jumptolive
01-04-2009, 07:24 PM
Yes, bfisher, I used to be a Skydiver! But got a new hobby and had to cut it out. Married with Children. Now it is all Hunting and Golf. :o

I will be interested as to your findings with the MOAB. I am going to Chrono again to make sure the thing wasn't off and also lighten up the serving on the strings. For now the Cheetah shoots plenty fast enough for the whitetail but I plan on hunting Elk next season and would just feel better with a little more power for longer distance shots on a bigger animal.

As it is, I couldn't be happier with how well it groups my shots and how quiet it is. If I can get the output then it is the last Bow i will need for a very long time.

jumptolive
01-04-2009, 07:27 PM
Jack.
Thanks for all the tips. I will take a look at the peep. What do you use by the way? It may just be too much on the string and heavy arrows, who knows? Hopefully I will get it figured out and tuned just right. Let me know if you ever get the chance to shoot yours with a Chrono. :o

flytier17
01-05-2009, 07:30 AM
Yes, thats right about that guy on bcountry. He CNC machined his limb pockets on an angle to eradicate cam lean, and picked up a ton of speed.