PDA

View Full Version : not getting speed expected- switchback



booner186
March 21st, 2005, 07:17 PM
:confused:
New switchback, 28.5 inch 70 pounds, 5575 arrow - 350 grains. Only 288 FPS.
My friend is shooting swithcback at 27.5 inch, 65 pounds, 5575 arrow, 350 grains at 288 FPS. ???
Any suggestions as to why?

Kelsnore
March 21st, 2005, 07:34 PM
How much stuff do you have on your string? Whiskers, Metal loop, brass noks, peep tubes, and such all take there toll on speed!
I just sold an 28.5 Allegiance set up with loop and peep (70#-350 gr.arrow)that left shooting 307 fps. With the specs listed on the SB, I would think you shouldn't be too far behind that!

1horn
March 21st, 2005, 08:08 PM
If the spine is on the limber side, it will come out slower also.

oksorb27
March 21st, 2005, 08:23 PM
I had a Switchback for 2 days and I could not get the speed I wanted either (290fps) so I sold it. I only had a D loop and peep on the string. Shooting a 327gn arrowat 65lbs- 28.5 inches. I was very dissapointed. I switched back to my LX 28.5- 65lbs, 327gn arrows at 301fps.

Tn10point
March 21st, 2005, 08:26 PM
Check and see if your bow is in spec. ATA 33" BH 7"from burger hole to back of the string [shooters side of the string]. Check your cam rotation the timing holes should run parallel to the string. If tilting toward the riser twist the cble on the cam end . If the holes tilt toward the string put equal amounts of twist in each end of the string. Hope this helps

archer2
March 22nd, 2005, 11:24 AM
I agree with checking the bow specs. The specs of the bow will make a big difference in the performance. I really spent a lot of time with my Switchback to get it exactly where I want it after everything settled in.

thndrr
March 26th, 2005, 04:45 PM
sometimes speed "claims" are very "approximate"..... :embarasse

fatboy111
March 27th, 2005, 07:56 AM
The Switchback is a great bow, but I too have not seen the speeds they claim. As mentioned earlier by archer2, check the timing marks. Speeds are approximate.

4snshine
March 27th, 2005, 08:04 AM
i'm happy whith mine,292fps @65lbs with 29" draw and 326 grain gt pro22's.i feel this is respectable speed and the bow is very accurite! i've only had it a little over a week,but i'm glad i bought it! just hate october is so far off!

Daniel Boone
March 27th, 2005, 08:30 AM
You can use the following to work backwards off listed IBO specs, this will put you pretty darn close to chrono:

IBO Specs - 30" draw/70lb draw weight and a 350gr arrow.

For every inch of draw length you go down you will lose 10 FPS

For every 5# draw weight you go down you will lose 10 FPS

For every 3 grains of weight your arrow is over IBO ( 5 grains per pound) you will lose 1 FPS

For every 3 grains of weight you add to your string you will lose 1 FPS.

Purka
March 27th, 2005, 07:38 PM
My Switchback is 30in 70lb , arrows 350g. I'm getting 309fps.

t8ter
March 27th, 2005, 09:27 PM
30in draw @70lbs.410gr arrow 291fps

meyerske
March 28th, 2005, 12:44 PM
I have a 29", 70 lb Switchback.

Here's the skinny to a detail...

Shooting a 399 grain Easton Axis 400 arrow. Bow is set at 70 lb measured. I have String Leeches, a knotless string loop, a tiny serving nock (not a metal nock), and an aluminum Fletcher-style peep served in.

Mathews claims 318 fps IBO. Right?

I'm chronographing consistently at 284 fps with my set up. Read on...

Now, using Daniel Boone's rules of thumb from previous post:

Subtract 10 fps for 1" draw length difference from IBO specs, then subtract 16 fps for arrow weight more than IBO spec (399-350=49 then 49/3=16.3 fps), then subtract 3 fps for peep (weighs in at 8 grains), then subtract 2 fps for loop (weighs in at 5 grains)...

318-10-16-3-2=287 fps...I'm at 284 PLUS I have string leeches installed which weigh 60 grains but are near the limb tips so I did not directly subtract their weight (plus I'm ignoring my serving nock weight and peep tie-in serving weight, both are tiny). I've read on other AT threads that Leeches slow your bow 2-3 fps. So, 287-3=284 fps.

So there you are...I am dead-on with what Mathews claims. No BS. :)

One thing I did find was that you gotta make sure that your brace height, ATA length, and cam rotation are set properly or you will lose speed, etc.

Bottom line: I'm very happy with this bow.

Hope this helps to provide info.

TANC
March 28th, 2005, 01:31 PM
And what Daniel Boone's stats don't account for is speed lost with some types of arrow rests, which can also be significant. Older whisker biscuits - for example. The newest ones only account for about 4 FPS loss.

Meleagris1
March 28th, 2005, 01:48 PM
And what Daniel Boone's stats don't account for is speed lost with some types of arrow rests, which can also be significant. Older whisker biscuits - for example. The newest ones only account for about 4 FPS loss.

I'm not losing any speed, not even 1 fps, with the new B2 biscuit and my ACC's and Blazer vanes (compared to drop away).

TANC
March 28th, 2005, 01:55 PM
I think Blazer vanes may be the reason. Typical loss with 4 inch vanes is 3-4 FPS - and proven. I have chrono'd with new biscuits and without (drop away rests), but have not experimented with Blazers through biscuits. Blazers are smaller and likely provide less resistance at pass through.

Andy Pappas
March 28th, 2005, 08:37 PM
It never stops amazing me what some bow companys will clame in order to sell a bow.


P.S. Sometimes shooting faster arrows will just make you miss your target faster.

meyerske
April 3rd, 2005, 03:57 PM
As an update to an earlier post I made on this thread...

I removed my string leeches (since I installed an STS system and no longer needed the leeches) and I picked up 4 fps, so I'm now shooting 288 fps. That's actually a little faster than the Mathews IBO speed, when you take into account the speed adjustment rules of thumb.

goldtip05
April 3rd, 2005, 04:23 PM
i have a switchback set at 63lb 28.5 draw goldtip 5575 which is 373 gn and peep,string loop thats it getting 260ft.bow is nice to shot and iam not a speed guy but 260ft come on.i saw a guy shooting a switchback this weekend 65lb 28.5 draw with cx200 247gn arrows 290ft not bad so i got some to try so we will see. :confused:

rivera68
April 4th, 2005, 03:11 PM
I have chrono my Switchback and i have a 26 1/2 inch draw @ 70lbs. with Carbon Express CX200 with 85grn (329grn total) field tips and it hit the 271fps. I think it's impressive with my short draw :cool: :thumbs_up

centerpunch11
April 9th, 2005, 08:47 AM
On my bow 30" 64# with a 320gr. arrow. It was getting 304fps. Cam timing is "EVERYTHING". As usual the factory mathews string and cable stretch. Before i adjusted the cam again, 3rd time now, it was only getting about 296fps. I am going to order a new Vapor Trail string and cable, The cam timing is the most important part of the tuning process.

steve hilliard
April 10th, 2005, 10:07 AM
Like DBs chart, I have always found that at 28-281/2 inch draw, if you are shooting in the 280s that impressive! and to be getting 288, that is great. I wouldn't complain.

soccert
May 12th, 2005, 10:07 AM
If I was getting 290 and the bow is shooting great I would not get rid of it to shoot 301 or whatever. I can't believe so many people are hung up on this speed issue. What do you think you will gain with the extra 10 ft besides the 10ft. I shoot a lot of 3d and my Conquest3 is shooting around 285, plenty fast and hitting 12'ves. If it was shooting 295 it would not make much of a difference. I do like a fast bow as much as the next guy but think about other factors as well, besides speed.

28LX
May 12th, 2005, 09:55 PM
Like DBs chart, I have always found that at 28-281/2 inch draw, if you are shooting in the 280s that impressive! and to be getting 288, that is great. I wouldn't complain.


I agree!! You are in the 28" draw range. What do you expect? 288 fps is a very respectable speed for a bow as smooth and quiet as the Switchback. This is a great hunting bow. The Switchback is primarily a hunting bow I dont understand why you need over 288fps to hunt???

antlers21
May 13th, 2005, 08:31 AM
I shoot my switchback at 70 lbs, 28" draw, with nothing but a peep and a string loop and I shoot at 288. I think you are right on. You have to remember that you lose 10 fps every inch draw legnth you will lose under 30".

SCHOOLCRAFT
May 13th, 2005, 09:56 PM
I posted this earlier, but I'm not getting as much speed out of my SWB as I thought either. Can someone back calculate my setup for me?

28" draw @ 72 lbs. (measured)

brass nock (I know...I should go to a serving nock...don't say it)

string loop

2 "golf ball" sized cat whiskers (I know...I don't need them...don't say it)

Easton Axis 400's @ 402 gr.'s total weight

I replaced the factory strings and cables with a set from Jarrod at Vapor Trail.
263-264 fps.

Any ideas guys and gals?
schoolcraft

antlers21
May 13th, 2005, 10:17 PM
Schoolcraft, you are right in the ballpark. You will lose 20 fps from 28"draw, 17 fps from arrow weight, around 10-12 fps with silencers and nocks. That is right there.

meyerske
May 13th, 2005, 10:56 PM
Schoolcraft - What speed were you expecting with your setup?

By the way, put an STS system on your bow and give the silencers to the cat. Did you use a brass nock because lead wasn't available?...Get that metal off of your string! :)

Seriously, check the ATA, brace height, and cam rotation. You'll get the right speed. If you need help on this, ask. Sounds like you have some cable adjustments to make since you are at 72 instead of 70 max.

When your bow is set to factory specs, it is at peak performance, anywhere else it is not and you will lose speed. With the Vaportrail threads it should stay in spec once set.

bowhunter357
September 20th, 2005, 10:54 AM
Just my 2 cents, cam rotation is the most critical. You can have your ATA at 33" your peak weight at 70lbs and still be as much at 12 FPS slower than you should be merely because of cam rotation not being correct.

S.E.Hunter
September 21st, 2005, 09:40 AM
If the bow shoots like you want it don't worry about it. I could secretly slow your bow down 10 fps and most wouldn't notice.

silverback
September 21st, 2005, 10:13 AM
sounds reasonable to me, but check your centeshot, that can rob some speed

xtremetj
September 21st, 2005, 10:34 AM
If you want more speed get a Allegiance ;) . Just kidding. I think your right on the money. I shot a few SB's before I bought the Allegiance. I shoot 28.5 dl, 70#'s and a 365 grain arrow with loop and peep and consistantly got 285 -288 fps out the SB's that I shot. My Allegiance set the same is giving me 302 fps :D . I'm not a speed freak, I just happen to shoot the Allegiance better and as a bonus it's faster. I don't mean to start a war here either. Just stating what happened with me.

Greg.

rjjacob
September 22nd, 2005, 10:22 PM
speed speed more speed









mathews LX
30 inch draw
67#
speed fast enough
truthfully the sped is scary

SirWilliam
September 23rd, 2005, 03:33 AM
I agree with checking the bow specs. The specs of the bow will make a big difference in the performance. I really spent a lot of time with my Switchback to get it exactly where I want it after everything settled in.

True...

SirWilliam
September 23rd, 2005, 03:39 AM
I agree!! You are in the 28" draw range. What do you expect? 288 fps is a very respectable speed for a bow as smooth and quiet as the Switchback. This is a great hunting bow. The Switchback is primarily a hunting bow I dont understand why you need over 288fps to hunt???


Thank you! That's what I was thinking exactly! :teeth: