PDA

View Full Version : '09 Bengal - New String/Cable fps loss?



RLW
03-01-2010, 07:24 AM
Being frustrated with the stock string/cable stretch and fast serving wear on my '09 Bengal, I got new Winner's Choice string/cable installed last week and now really confused.

When shop installed them for me, the axle-to-axle was way off and max draw weight low, so went back and we twisted cable to get back to what I had measured prior to change, at 32.375" (claimed factory spec is 32.25").
I also had them change module for me from F5 on Pin2 (28.5" DL) to F4 on Pin 1 (28" DL).....after ATA correction, also adjusted draw weight from previous 64lbs to 66lbs which should have compensated for small DL change.

So along with string/cable change I've shortened draw length 1/2", and increased draw weight 2lbs.......all else is the same, but shooting thru my chronograph, I dropped from 268fps down to 253fps (same 425gr arrow)

I've had some change in speed before on a string change, but nothing close to this drastic.......15fps drop to me means something is wrong....I want that speed back, so any ideas would be appreciated.


Now I will say, more importantly, it bow is shooting very nice. During my re-tune got my first robin hood

drevilmike77
03-01-2010, 08:09 PM
mt Bengal was shooting 275 with Vaper Taril strings and a 355grain arrow at 64Lbs. and a 28" draw.

RLW
03-02-2010, 05:46 AM
mt Bengal was shooting 275 with Vaper Taril strings and a 355grain arrow at 64Lbs. and a 28" draw.
Which sounds right to me and what I would haved expected, just like mine shooting a 425gr arrow at 64lb w/28.5" draw "was" 268fps prior to string change.

What I haven't figured out yet, is why I lost 15fps basically just changing string/cable

RLW
03-10-2010, 07:59 AM
Thought I'd give an update that I learned what my speed loss problem was.

Prior to buying, during test shots, the dealer had changed module to fit my normal 29" draw better......which I was told was a F5 module.
Being a lefty, can't read module number w/o taking module off, so believe this to be true and bought it that way. Later I had gone back and had them move to Pin 2 on this module because it felt a bit long. (I am a long time finger shooter, so new to releases & taking awhile to figure out what's right for me)

When I got the new string/cable, while they were changing things, I asked to drop me another 1/2".......based on what I assumed I had, meant F4 module on Pin 1.

After posting above frustration and confusion, I looked back thru my module pack I noticed the F4 was not in there and assumed on the bow, but also noticed that I was missing the F5 and had ( 2 ) F6, one aluminum and one composite like the others.

The aluminum one had been on the bow, and could see how the stamped number "6" could have been mistaken for a "5", so I compared the two.
Turns out I had a F6 module....the supposed 'dud' module for a Bengal.....on the bow the whole time.
Now it makes sense why draw length always felt a bit long, why the later change to F4 felt too short (even after correcting cable length), and why the speed dropped so far.

Got a F5 module, bought a Bowmaster portable bow press, and reset everything myself this time.

The Winner's Choice string/cable does have much more serving on it than the factory Martin set, especially on the string w/approx 12" extra where it wraps around the idler wheel, so maybe loosing 1-2 fps there, but current speed is now:

'09 Bengal w/F5 module on Pin 1, 32.375" ATA, 65lbs, temporally still w/tube peep (have G5 to put in), shooting my 425gr arrow at average 263 fps.
Still a little low, but much more reasonable.

bowgramp59
03-10-2010, 07:29 PM
go to the bow cam chart on this sight it says for the 09 bengal string 90" and cable is 34" believe me that 1/4 " will make a big difference.i gave my string maker the wrong measurments on 2 moabs, i had three set of strings made for an 08 moab and 2 09 moabs i just looked at the 08 and gave him the the same lengths for all 3 cables there was 1/4 diff. in them none of your settings will be right ata. brace ht. and draw wt. if the cable is to long you will never be able to twist it enough to get your proper draw wt. if it is to short the draw wt will go way above factory specks, my 50# bow went to 65#s. all three strings were 90" but not the cables.:confused:

RLW
03-11-2010, 06:02 AM
yep we were good there.....since it was so far off after restring/cable, I did recheck string/cable lengths, and they were as ordered, per Martin factory sticker that came on bow.

For a standard factory '09 Bengal, a 90.0" String and 34.0" cable is correct, but as offered thru Cabela's, where mine was purchased, it included optional STS and CCS....the CCS adds 1/2" to cable making it a 34.5", basically same as '09 Moab (w/CCS) cable length