i have a matthews dxt and it's advertised @ 326fps IBO. i just chronographed it today and was getting 262fps with it set up to hunt.
i have a 28" draw and have it set at 70lbs. i am also shooting a 395gr arrow (approximate). does this seem right to you guys? i was kind of surprised at the difference.

what are you guys shooting and what kind of real world speeds are you getting.

i'm not concerned just surprised at the difference. i know the how the IBO test is conducted i just didn't realize there is that much of a difference.

I have a 30" draw and shoot 65 lbs from my Alpine with about 430 grn arrows I get 275 FPS.

That's a good bit slower than I would expect too.

Maybe your arrows weigh more than you think, or draw length is shorter, poundage is lower, arrows are weaker... could be several things.

Maybe you have some rest interference with the fletching. Your cam timing might be way off. That can eat speed too.

Or maybe it is absolutely reasonable. Don't know for sure. I don't blame you for wondering. I would too.

I would have expected the speed closer to 275 to 280.

But then in bow hunting speed is not everything.

If your setup shoots accurately over your hunting distances then why chance it.

I prefer a silent and a bit slower bow than a speed bow making a lot of noise...

Your best speed for a fix broadhead are 270fps, with that speed you get you will have good groupings on your broadheads! Yes it is a bit slow but its not a new bow,every body are running after the speed,but its like Gerhard said a softer bow are beter than a noisy one!

To get that IBO you must remember they put it on 70 pounds on 30 inches with a verry stiff arrow without flethes!!!!

I work in a bowshop partime and have tested a lot of bows and not one of them had ever got close to there IBO......

Well good hunting!

The more I think about this question the more I suspect your cam timing. Single cams like Matthews don't get out of sync but sometimes the cam start point gets out of adjustment because of string stretch.

Have your pro-shop check to make sure that cam is in the proper start position.

alright i'll have to check that. thanks

"Also worth noting-Mathews cams have a specific position to achieve max performance. I have talked to dealers that pay no attention to this. A Mathews cam out of position will still yield good enough accuracy and forgiveness that the average guy would not know the difference, but the chrony would"

i found this on another forum and am going to check this

alright i just got back from the bow shop and my cam was out of position. he showed me how to check and it's pretty simple. the poundage was only at 65 with it cranked all the way down, after he moved the string it's back at 70lbs. i'll chrono it later and see where it's at now.

alright i'm at 275fps now. that seems better. would an aftermarket string make a bow faster? just wondering.

Leave it alone.

quote:

Originally posted by Nick321:
alright i'm at 275fps now. that seems better. would an aftermarket string make a bow faster? just wondering.

I wouldn't put a non-spec string on just about any bow. The returns in getting just a little bit more speed from a non-spec string aren't worth it in my opinion.

That being said. You lost 5lbs in draw weight and the cam was out of position. That should be a big clue it is time for new strings and cables. A new string will be a little stretchy at first but they usually stop stretching after the first 100 or so shots. When they start stretching again it's a sign they are getting worn out. Loss of draw weight and cam out of position are definite signs of stretching.

I wouldn't suggest you try to put a faster string on there but I would recommend you replace the one that's on there.

big guy thanks,
what is your opinion on winners choice strings, they make a string for my bow. or should i go with a Matthews factory string?

quote:

Originally posted by Nick321:
big guy thanks,
what is your opinion on winners choice strings, they make a string for my bow. or should i go with a Matthews factory string?

I've had very good luck with Winner's Choice strings. I believe the Matthews Factory Strings are Zebra Twist. I've never used the ZT strings but they have a very good reputation.

If you're happy with how the original string performed then stick with the same kind.

Like it was said Bow speed is always at 30" draw. I have a 28" draw too I said that I would not buy a fancy bow until I could get One to shoot 280 fps at 28". I went to the local pro shop and he had 10 to 15 diffrent bows. I shot a Bowtech and then we crono it with my draw lenth. At 65 lbs 28" draw I shot at 286 fps.
I was very Happy , but did you know a compound hand Held has more Kinetic energy than a Crossbow

Nick,

the speed manufacturers use is IBO legal; 70lb bow, 30 inch draw, and a 350gr arrow. Any other numbers cannot be compared.
For comparison, I have an old (2004?) Hoyt Alpha-Tec. Maxxed out at 70 lbs and a thirty inch draw I shot a cut-down (28 inch) Carbon Express Maxima thru the chrono over 270fps, and hit the bull. It was almost dry firing the bow, and two arrows were all we did.
Only the IBO numbers are valid IMHO.

Rich
DRSS

One thing you have to know about IBO Speed Ratings. That speed is rated at a 70 # pull with a 30" draw using 350 gr arrows. Now ask how you can shoot a 350 gr arrow, you can't. Most manufacturers will void the warranty with anything less that a 400-420 gr arrow. So if you reduce that draw length or pull weight you reduce the effectiveness of the equipment, couple that with an average arrow weight of about 375-425 gr for 26-30" arrows depending on spine and you can see where your speed is going.

Thndrchiken,

you might want to rethink that notion.

Mathews, Hoyt, Bowtech, and PSE (I know, I asked my local guy and he looked up the warranties) all specify a minimum of 5gr per inch arrow weight. Manufacturers all adhere to the IBO numbers when designing a bow these days.

Take the IBO number, at 70lbs and a 30 inch draw: 5gr per inch = 350gr total weight.
Obviously, nobody in their right mind hunts with an arrow that light. 400gr minimum here in Idaho.

regards,

Rich
Mathews Monster Seven

Well then to use your analogy then why are the manufacturers publishing a rated speed that is completely unrealistic, illegal in many states to hunt with an arrow that light and in some situations dangerous.

Now take that 5 gr per inch and tell me what arrow you can buy that when factoring the weight of the shaft, insert, nock, vanes and tip will come in at 5 gr per inch. You can't even get an arrow with a spline rated for less than 50 lb pull.

I may not be the most experienced archer here but it's not rocket science. IBO Speed ratings are good for nothing but a marketing tool to dupe uneducated consumers.

I'm a little confused. IBO is a standardized way of measuring-a good thing. What about bows that are less than 70 lbs? i know with trad equipment it's based on arrow weight in grains per pound of draw weight. Also based on a 28 inch draw. Are you sure it isn't the same with wheelie bows?

quote:

I'm a little confused. IBO is a standardized way of measuring-a good thing. What about bows that are less than 70 lbs? i know with trad equipment it's based on arrow weight in grains per pound of draw weight. Also based on a 28 inch draw. Are you sure it isn't the same with wheelie bows?

It is a standardized measurement, but it is a completely unrealistic value for what the bow is being marketed at. There is no way that you can get a 350 gr arrow with a field point/bh, insert, nock and vanes and still be splined properly for the pull weight. Using say 8.5 gr per inch on most shafts rated for 55-70 lb pull arrow weight would be around 400 gr using a 100 gr tip, move up to a stronger spline that weight goes up from there. Shoot a lighter splined arrow and it becomes a dangerous situation.

Then not to mention that it is illegal to hunt with an arrow that weighs less than 400 gr in many states.

IBO is like NASCAR.

That said, you have to have some uniform way to compare compound bows. The average shooter wants to know how the bows compare on a level playing field.

Most bowhunters I know here in Idaho are shooting seventy pounds. They draw from 29-30 inches. Their arrows are minimum IBO weight. They converge at 3D shoots around the chronograph. They also have pins set out to eighty yards, and can hit a pie plate consistently at that yardage.

The Carbon Revolution Speed Pro Max is 5.5gr per inch shaft. Old Geezer Disclaimer: I shoot them in my old Hoyt Alpha TEC; 50-60lb limbs. They had the five inch deep riser, factory overdraw. With a thirty inch draw the arrows are actually cut to a nock to tip length of twenty eight and one quarter inches length. They weigh 302.4 grains. They are fast, and group well out to sixty yards. At sixty pounds they are just legal enough to make weight at my draw poundage anywhere in the country.

Absolute speed is fun to play with, but grouping is the answer. You can shoot thru a Moose broadside with a fifty pound bow and sharp broadheads at fifty yards.

regards,

Rich
Mathews Monster Seven this fall

Don't even pay attention to marketed IBO speed rating claims by manufacturers, you will never duplicate them. It's kind of like fuel mileage ratings for trucks, they take the one time achieved rating under ideal conditions and then throw that number out there.

IBO ratings for bows are with a bare string, super-tuned bow 30" draw and yes 5 grain per inch arrow. Hoyt is about the only company that doesn't inflate their speed ratings. Matthews way over-rates their speed claims.

I do own a small archery shop in Utah and have chronoed a lot of bows, you'll drive yourself crazy if you think you'll ever achieve claimed speeds.

Nick don't listen about a "non-spec" string. Winners choice strings are great, won't twist or stretch but they are spendy. There are lots of aftermarket custom string companys and a custom string will be much better than a factory string. Try vapor trail strings, they are about half the cost of winners choice and everybit as good. PM me if you have any more questions or check out www.archerytalk.com forums.

I just reread the regs. Idaho has dropped the minimum legal arrow weight to 300 grains.

Filmit, I'd love to drive from Nampa down to your shop some day and do some shooting with you. You got one of those fancy Hoyt Chrono units with the Bow Force release-looking things that measure the entire draw?

I was weighing some of my 28 1/4" arrows I shoot in my old Hoyt Alpha-Tec and chronographing them yesterday.
My A-T was measured at 54lbs, and the arrows were as follows:

1. X7 2613 507gr 228/227/228 fps
2. Beman ICS 500s 275/275/275 fps
they had those white ring whatever vane-thingies on them. Weird, but not as noisy.
3. Carbon Revolution 35-75lb spine Speed Pro Max 302gr 282/284/283 fps
I am very curious to see how they will fly with a 125gr Muzzy

It is interesting to see that a 507gr aluminum arrow shoots 55fps slower than the Carbon Revolution that is 205gr lighter.

The Monster 7 at 58lbs shot a 30 1/4" Carbon Revolution arrow that weighed 314gr 317.317/317 fps
Seven years of technological advances do count for something it seems. I want to work it up to 70 lbs/350gr arrow and see how close I can get to the Mathews claim of 342 fps.

Rich
Mathews M7

sharpshooter it's just a standard chronograph that I use but you're welcome to come by anytime you're in the area. I'll send you a pm on the whereabouts.

you can find ultralight arrows nearing the 5gpi with proper spine, you just have to look and spend lots of money. but most agree to not hunt with them. you get flat shooting, but less momentum, which is needed for penetration.

Winners choice strings use to be good, their quality control has dropped, and my experience, as well as most everyone i know in the last couple years, will never purchase anohter one. my WC string stretched so much it could not be safely twisted enough to bring my mathews back in spec.

for your mathews, they have the zebra strings, and the upgraded cuda strings. they are pretty decent for factory strings.

as for your comparison, i was shooting my mathews outback at 72# and 30". i shoot easton a/c/c at 479gr total arrow weight, and shooting a fall away rest. i was getting 270fps out of it.

i have since switched to the bowtech destroyer 340, also 30" and 70lbs. qad fall away, and the same 479gr arrows. i'm now a consistent 288-290fps through my chrony. i would like a little more foc in my arrows, so i may cut them a little and add some weight to the tip (i shoot 100 gr tips), but i shoot it good out to 80, and it will kill the small eastern whitetails we have, so for this year at least, i'll leave it alone.

If you are happy with your feathermax, keep shooting it. but if you do decide you need a new toy, go to as many bow shops as in your area, and shoot every new bow you can get your hands on. try not to look at speed numbers, just focus on which one you shoot the best. for me it was almost a 3 way tie between the mathews monster 7, elite judge, and destroyer that i ended up getting. to me the bowtech was just a little smoohter and had a little better draw cycle than the monster. the elite had the most awesome draw stop i've ever felt on a bow, but it had more hand shock than the bowtech. i shot many more bows, the bowtech just fit me the best and i liked it the best.

also be careful of getting too fast with fixed blade bh's. i switched over to the atom head, and i will see in the next week how they shoot at my increased speed. i will also test out my muzzy's and montecs and see how they like the speed.

enjoy.

quote:

It's kind of like fuel mileage ratings for trucks

This is the key answer to "Why doesn't my bow shoot the IBO numbers?"

Marketing, marketing, marketing.

An IBO rating is not ideal, but the manufacturers at least agree to that standard, and IBO tests them. That is why the 2010 models all say "up to XXXfps" now.


Rich

Get your chrono out and measure... no better way than that. Penetration is more important than speed, finding the right weight combination is critical

Many deer have been taken with arrows traveling at speeds far below what your achieving. (Think of the women shooting 40lb bows and killing many deer.) With decent broadheads and correctly placed shots, you'll get many deer. My guess is that most people are only achieving 80% to 90% of the bow's advertised speed. Below is a website that deals with this subject. I think you'll find it interesting.

www.huntersfriend.com/shootout/shootoutR1.htm

quote:

Originally posted by thndrchiken:
IBO Speed ratings are good for nothing but a marketing tool to dupe uneducated consumers.

Pretty much. Yep.

It's like rating the fuel economy of a Chevy Suburban at 70 mpg because it really will achieve that number when it is coasting downhill.

Once upon a time we had a 540 gr. 60# 30" draw rating system called the AMO speed. While maybe not completely reflective of today's light arrow craze, it does represent a standardized, achievable quantity.

Glad you were able to work out your problem really goes to show how important it is to know your equipment, little out of tune and you loose 13fps!

My bow is pretty close to AMO standard, but I bought it when that was still typical measurement. It is a 1991 Darton 400MX 62#'s with 30" draw

Shooting 29.5" 2413 XX75's @ 489gr I get 212fps
Shooting 29.5" axis FMJ's @ 452gr I get 222Fps

Not bad for a 12 year old bow!

the importance of a good bow tech cannot be over emphasized. I pay a little more to buy at my local guy, but he has been to all the factory schools for the brands he carries. He was willing to put in an afternoon, off and on, tinkering with my Mathews M7 with the chrono. It gained nearly 40fps over that testing period.

Rich

Bow speed is just another version of "mines bigger"! Oh yeah and MINES BIGGER!

Mathews Z7 with 29" draww length set at 58# is shooting 275 with 390 gr arrow

Shot 120' doe last weekend with the Magnus stinger 100 gr 4 blade, shot through ribs one side and cut top of leg bone on off side, it was just hanging there, was rally inpressed with these broadheads, another thing, tuned to shoot with my target points, they all shot to sae place, no odd arrows 3 or 5" out of group

They will be my standard broadhead from now on.

I just weighed a carbon express maxima 250 with 4" vanes at 27 1/2 " with a 2 blade rage broadhead and it came in at 350 1/2 grs.on my powder scales. I shot it through my chronograph at 61 pounds and the speed was 277.1 fps avg. with a 28in draw,deadend stringstop using a mathews switchback xt. Turned the bow up 1/2 turn and got 281.1 fps but not sure of the poundage but my bow is not maxed out yet, 1/2 more turn to max. I know I'm light but i don't think thats to bad for a xt with a 28" draw, something to think about for 28" draw users. 69 lbs is max for the 27" carbon express maxima 250 spline.

I have been thinking of a new bow for more speed but dam looking at the numbers my 15year old darton at 246fps 73lbs 29in draw doesn't seem to bad at all.

It would be hard to justify a 1000 dollars for 30fps more.

I just cronyied a parker cross bow for a freind we avg 329fps.

well I am in Minnesota and all they have is a Min LBS wich is 30lbs draw... and in 2007 i shot 3 deer with a 315gr arrow and all were pass throughs it was a Bow Tech Gardien 29.5" draw and 57lbs draw and a 27.5" CX 200 with blazer vanes and a 75gr Rocket wolverine the arrows were going 318fps and one deer was a mid size doe shot at 50 yards ..

and my curet rig is a 2003 hoyt pro teck at 60lbs and 29.5" draw shooting a 344gr arrow at 278fps and still getting pass thrus on my deer .. I have don lots of testing for KE and well just cam to the conclusin for white tails in MN Dead is dead weather it be 56lbs of KE or 90lbs of KE they dont die any faster with one from the other