Tuning Sanity Check

[kad11]

I'm working on tuning a 64" Greatree Highlander riser w/ Carbon Maxx limbs. It's 45# @ 28", 8" brace height, 3 Rivers 8125 string- I'm drawing 31.5" and shooting 32" GT Velocity 300 shafts with 2" long, 150 gr brass inserts. I used the spine calculator on 3 Rivers and thought I'd be able to dial things in using a point weight in the range of 125-175 gr. However, I keep getting stiff spine readings with points as heavy as 300 gr.

Does this seem way out of whack or is a 300 spine shaft just really too stiff? Would pulling the 2" long, 150 gr brass inserts and replacing with the much shorter standard length aluminum inserts get the arrow to act weaker? I'm not sure whether point weight or effective shaft length has a larger impact on dynamic spine behavior.

I understand no one can give me a definitive answer - just looking for some general guidance and tuning education from more experienced guys. Thanks!

 

[ozyclint]

Well if a 300 spine is expected to work with a 45# bow then there isn't an arrow made that will work with a 70# bow.

Too stiff

 

[kad11]

I'm probably at 52-53#, but yea I get your point.

 

[Blackcow]

I’m a 31.5” draw and most of my bows are 51-52 & 31.5”, or 45&28” and go 51-52# at my clicker. A full length gold tip traditional (.246) .400 spine will shoot a touch weak with a 5Ogr gold tip aluminum insert (about 2”), 150 tip and 15 gr footer up front, a wrap, 4 3” trad vanes, nock bushing and g nock in the back. I can get it to bareshaft perfectly leaving centershot alone and lowering my brace a little and moving string silencers away from the limb tips more. With a 50gr brass insert, I have to go to a 125 and 100 is better. .340’s are money with a broader range of tip weights and inserts, in both .246 and .204.
A .204 .400 spine won’t come close unless I move centershot WAY out.
I can shoot .300 spine especially on my uukha limbs, but I’m right down the middle centershot on a gillo ghost riser, and like 300 up front . On my widow and bob Lee’s, it’s a no go for me with .300’s.

 

[kad11]

I’m a 31.5” draw and most of my bows are 51-52 & 31.5”, or 45&28” and go 51-52# at my clicker. A full length gold tip traditional (.246) .400 spine will shoot a touch weak with a 5Ogr gold tip aluminum insert (about 2”), 150 tip and 15 gr footer up front, a wrap, 4 3” trad vanes, nock bushing and g nock in the back. I can get it to bareshaft perfectly leaving centershot alone and lowering my brace a little and moving string silencers away from the limb tips more. With a 50gr brass insert, I have to go to a 125 and 100 is better. .340’s are money with a broader range of tip weights and inserts, in both .246 and .204.
A .204 .400 spine won’t come close unless I move centershot WAY out.
I can shoot .300 spine especially on my uukha limbs, but I’m right down the middle centershot on a gillo ghost riser, and like 300 up front . On my widow and bob Lee’s, it’s a no go for me with .300’s.

Awesome, thanks for the detailed response! From your specs I think I should be able to get these 300s to tune. I'm going to try bumping the brace height up a bit more and finding a thinner strike plate.

Thanks again for the input.

 

[Blackcow]

.340’s are still probably the better choice, but you can probably get them to fly. I’ve used the fake leather vinyl upholstery patches for strike plates. About as thin as you can get( or duct tape lol). Check for contact for sure . You can think you’re good, but actually it’s just headed in the direction or a false weak, from smacking the sight window and kicking the back out to the left then headed right. Assuming you’re right handed

 

[TaterTot]

I'm guessing to stiff still. I shoot a 45# bow, I draw 29.75, I'm using a 400 spine carbon cut to 30.

In order to get that arrow to fly I have a 185 grain insert outsert, and a 175gr head.

 

[MontanaMarine]

I shoot a 45# Samick Discovery. Draw length 32", probably 55+ on the fingers.

What works for me is a 32" 340 spine, with 250gr up front.

 

[Quentin VanPelt]

I shoot 61 pounds at just a tad over 31 Inches. Bow is cut to center. I am shooting Easton axis .300s cut to 32 1/8 with 200 up front and they bareshaft a tad weak for me. With 175 up front they are just about perfect if I do everything right. I shoot 200grains anyway for just more overall weight. Factory 16 grain insert

 

[kad11]

Thanks everyone for the input - it's really helpful to see what other guys in roughly the same range are shooting.

I'd had these bare shaft 300s lying around for a couple years so decided to give them a go first, but 340-400s sound like they'll be more appropriate. Thanks guys

 

[CamoPirate]

Wonder if it's bow specific. My Samick discovery/uukha limbs is 53.5# on my draw (29/30 in), I'm shooting 300s at 31", and have em tuning with 250gr up top (100gr brass inserts/150gr points).

 

[oldgoat]

Wonder if it's bow specific. My Samick discovery/uukha limbs is 53.5# on my draw (29/30 in), I'm shooting 300s at 31", and have em tuning with 250gr up top (100gr brass inserts/150gr points).

That bows riser is cut past center, it will take pretty stiff arrow to counter that, so yes very bow specific, but riser cut depth to be more specific.

 

[oldgoat]

I'm working on tuning a 64" Greatree Highlander riser w/ Carbon Maxx limbs. It's 45# @ 28", 8" brace height, 3 Rivers 8125 string- I'm drawing 31.5" and shooting 32" GT Velocity 300 shafts with 2" long, 150 gr brass inserts. I used the spine calculator on 3 Rivers and thought I'd be able to dial things in using a point weight in the range of 125-175 gr. However, I keep getting stiff spine readings with points as heavy as 300 gr.

Does this seem way out of whack or is a 300 spine shaft just really too stiff? Would pulling the 2" long, 150 gr brass inserts and replacing with the much shorter standard length aluminum inserts get the arrow to act weaker? I'm not sure whether point weight or effective shaft length has a larger impact on dynamic spine behavior.

I understand no one can give me a definitive answer - just looking for some general guidance and tuning education from more experienced guys. Thanks!

Only recurves I shot 300 spine from were around 62ish pounds at 31", guessing 340 spine for your setup, I'm working up a similar spec bow and that's what it's seeming to like with 320ish grains up front on 32" arrow

 

[Beendare]

Delete

 

[Quentin VanPelt]

From the tuning I have done it seems harder to weaken up an arrow than stiffening it. The center shot on a bow defiantly plays into that as well. I bought some grizzlystik 240 for a good deal. I figured if a 300 shows a bit weak I should be able to make a 240 work. That was not the case. I needed 400 plus up front to make them half way decent flying with great form out of my 64 pound bow That made the arrow to heavy for my liking. I am debating on trying the 260 axis but I don’t want the same thing to happen again. I think I’ll stay with a slightly weak 300 for now.

 

[sneaky]

I shoot about 54-55#@31" on my 64" Stalker Coyote. 350s fly like darts, 300s always show way too stiff even when left full length and loaded up with 300+ up front. That 340-350 spine group always shoots better than those online calculators say they will. I don't even look at those things anymore. Once you tune one setup in that range you don't look at charts anymore, you'll have YOUR baseline to choose from.

Sent from my SM-G955U using Tapatalk

 

[TaterTot]

I find the online calculators fall apart as soon as you start moving into efoc ranges.

 

[kad11]

Update:
I swapped out my original strike plate for Leukotape and bumped the brace height up a bit. The 300s are still too stiff ( I think the visible contact on the strike plate is showing the shaft isn't paradoxing enough), but fletched shafts fly well with field points. I'll have to see how broadheads fly in the next week or two.



Here's a 15 yd group gapping off the tennis ball - I'm pretty happy with that for being a couple weeks into stickbow shooting.



I'm not really impressed with Greatree quality at this point - the quiver bushings fell out today and I'm finding some weird seams along the riser. Not sure if those are superficial or indicative of structural issues...

 

[kad11]

I’m a 31.5” draw and most of my bows are 51-52 & 31.5”, or 45&28” and go 51-52# at my clicker. A full length gold tip traditional (.246) .400 spine will shoot a touch weak with a 5Ogr gold tip aluminum insert (about 2”).......With a 50gr brass insert, I have to go to a 125 and 100 is better.

So the same arrow acts weaker with the (shorter) 50 gr brass inserts vs the 2" aluminums? Good to know that insert length impacts dynamic spine behavior...

A .204 .400 spine won’t come close unless I move centershot WAY out.

Does a smaller ID shaft act weaker because it's naturally closer to centershot?

I'm pretty new to recurves and just trying to make sure I understand the basic mechanics of how things work. Thanks!

 

[Blackcow]

Yeah, the smaller radius acts as if you moved center shot in. Not necessarily a bunch, but it does. Definitely noticeable between a .166 and a .246, at least for me.