Spine variation with carbon shafts

[Wheels2]

I tried testing spines of different makes of carbon arrows, each being marked the same spine, and found that two of the three ran stiffer than marked, while one was right on.

Have you tried the same thing with aluminum, especially the X7 Eclipse shafts?

Interesting stuff, but the differences are so small I don't find it worth while to worry over.

[**DONOTDELETE**]

Well i guess the bottom line is you only get out of this sport what you put into it...  The closer your arrows are to being exactly the same is going to give your shooting ability more accuracy.......

So after you go through all this stuff and get everything just perfect.... then you have to accept that your shooting form sucks...LOL...

If you don't go though all this stuff you can blame it on arrow spine...

   

  You can do what Howard Hill did. Just shoot all your arrows and throw out those that consistently fly off track.  

I've used this system for years and it's served me well.... But i've really had my eyes opened recently on the significance of bare shaft tuning. i think its definately worth while.

[wingnut]

McDave,

Orient your nocks 90 degrees to emulate the force of the arrow and test your spine.  That should be the same as the factory test for nock alignment.

Not sure how much difference it will make.

Mike

[McDave]

You're right Wingnut. I was trying to make it the equivalent of a wood arrow loaded with the grain vertical, and I guess my thinking was 90 degrees off.

[McDave]

This morning I went back and measured the spines on the same 6 arrows, rotating them 90 degrees as Wingnut suggested. The spines were very close to my first measurement.  Since my spine tester only has marks about every 25 units, I can't give the actual differences, but I would say they are all within 5 spine units of the first spine measurement.  Some were more, some were less, making me wonder if VAP really spends much time aligning the nocks, as they claim.

[Bldtrailer]

Ok how many wood shafts would you have to be spine test  and weigh to get  12 near the same spine and weight? Mother nature varies a lot  and someone must sit spine test and weigh long before they find a matched set.     blems) group and find I need to rotate my     nocks( most notable on bare shafts, stiff side vs weak side) to get the most constant flight.  

[bigbadjon]

Generally you must buy about 100 shafts to hopefully get a matched dozen. This is of course variable due to the nature of wood. RMSG sells them already matched for about the price of a regular unmatched dozen as long as you like poc.

[tzolk]

Is there reason to believe that the Full Metal Jacket Eastons may spine closer to specs than the Axis carbons, due to the aluminum outer?

[bigbadjon]

I have some FMJs I can check for you when I get home this afternoon. I know that they have no variance by rotating the shaft.

[tzolk]

Thanks! I sold all of my Goldtips off and found a good deal on a couple dozen FMJs and Axis Woodgrain. So far I like em.

[atatarpm]

That explains a lot of things to me about how I can make a wood arrow better than a carbon.  Need to spend more time working the carbons.    

[bigbadjon]

I just finished measuring those fmjs. They all tested .250 and as rotated the maximum variance on every shaft was .005. So that is right in line with the .300 listed on the shaft after conversion to Eastons scale. These shafts were FMJ DANGEROUS Game 300s.

[tzolk]

Nice!

[Jakeemt]

Interesting stuff guys thanks for the info! I shoot aluminums but, am set up to play with carbons too. This could come in handy.

[Kevin Dill]

Very educational. I went to the Easton site and spent some time reading about the various carbon and carbon/alloy shafts they offer. I came away understanding that some shaft types do have spine variances due to construction methods. Other shafts are made in ways which mitigate or nearly eliminate spine variations, and are consistent in spine despite nock rotation or orientation.

I wonder if there is an easy way to identify the 'correct' side of (example) Axis shafts without use of a spine tester...?

[LB_hntr]

This thread is very interesting and very educational.

I do have a question and keep in mind I don't hunt with many compound guys to know if this effects them.

Question:
If carbon shafts are so inconsistent how does the average everyday compound shooter shoot such tight groups at 30-50 yards and beyond with them. My buddy this summer picked up a new compound and a dozen goldtip arrows. We set it up and sited it in. An hour later at 80 yards (with a range finder) he was putting 6 out of 6 into a coffee can lid.
I think 99% of compound shooters shoot carbon and can shoot fletch eating groups all day. Why would these inconsistency not effect them as much. Spine is spine, so their tuning capabilities should not matter?

Thanks again for this thread. I learned a lot from it.

[Doc Nock]

Kevin,

Some claim you can put the raw shaft tip on a flat smooth surface and roll the shaft with your hand using the palm of the other hand to support the other end of the shaft. Supposedly, there is a "bump" felt on the stiff point.  I never could get it...maybe my palms have been abused too much?    :rolleyes:  

Jason,

Shot you a note... we might impart a lot more variations wrapping around risers and shooting fingers where the string can roll differently shot-to-shot so that it's US that the carbon reacts to requiring us create more consistency in the shaft's reaction to our variables, whereby those "other" types don't have that to contend with?    

[giff]

Originally posted by LB_hntr:

If carbon shafts are so inconsistent how does the average everyday compound shooter shoot such tight groups at 30-50 yards and beyond with them.

I get the feeling that most of the people on this thread do not understand how miniscule the variances are. We're talking thousandths of an inch.

Comparing them to wood arrows is a little ridiculous.

As far as rolling the shafts to find the stiff and weak sides, I've never tried, because it doesn't matter with a trad bow. At Olympic distance I might rotate the nocks a little, but only if I have a bareshaft "flier." Rolling them is a waste of time IMO, because they act completely different coming out of a bow than they do laying on a table.

[screamin]

If carbon shafts are so inconsistent how does the average everyday compound shooter shoot such tight groups at 30-50 yards and beyond with them.  

I think shooting a drop away rest set at centershot with a mechanical release covers up spine problems to some degree so fieldpoint groups are good. You would also be amazed at the amount of compound guys that claim broadheads won't fly with fieldpoints, that it is impossible.

I did notice back in the wheel days that I got much tighter groups shooting fmj's and axis over the competitors carbon shafts.

We have to shoot around a riser and deal with finger torque and possible string roll. Does it really matter at the ranges we shoot? I don't know, but since I like to tinker so much, I think I'll find out.

[Morning Star]

http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=138019;p=1

Here is a thread I started on the same a while back.

I've found Carbon Express shafts to be the most consistent.