# Uukha 2021 SX100 Limbs initial impressions



## vscarf10 (Dec 31, 2019)

Hello all from a first time poster!
I've lurked plenty on this forum over a long period of time and learnt so much from reading of peoples experiences with equipment, technique and so on which has helped shape my buying habits and kept my interest in the sport.

I've been shooting Olympic recurve for the last 16 months and shot compound on and off for a few years prior to that.

I thought that I would give a little initial feedback and comparison on my recent purchase as I know there are fans of Uukha limbs out there, more so in trad shooting but also a few in the Oly Recurve discipline and there's generally not many reviews on their equipment. I have been shooting EX1 Evo 2's for the last 12 months and treated myself to some SX100 that arrived yesterday and had a chance to shoot at 18m indoors last night

Disclaimer: I consider myself an intermediate recurve archer shooting once a week indoors and outdoor (8.7 arrow avg (72 arrow round) @ 18m indoor 3 spot vertical over last 4 months and in the last few months have concentrated on 70m and avg 7.66 per arrow (72 arrow round) so interpret my feedback as you choose!









My setup
Gillo GT 25
Shrewd Revel Stabilizers 28 & 12's and Atlas V Bar with 4" extender
Beiter plunger and Shibuya ultima II sight and rest
8125 String
Brace height - 21.8cm
Draw length - 28.74"
ACE 670 cut to 28.19" nock groove to shaft end with 100grn points, arrow wrap and Eli vanes P3. Arrow weight 279 grns
Centreshot - point of arrow tip every so slightly left of string.


Initial impressions on the SX100 vs the EX1 Evo 2

Pros-

They have a very nice sound and feel to them. I always thought that my EX1's had a little too much low frequency hum/vibration to them after shot and could not get it out no matter how much I played with brace height ranges or tiller. The EX1 had a robust and rigid feel to them that I liked but the SX100 are so much more quiet and settle down very quickly after shot. To me the sound and feel difference is night and day!
The draw is smooth from start to finish. The EX1's had a little heavier back end on them but nothing drastic. The SX100 at the same OTF weight feel smoother through the clicker and feel like I'm holding 34-35lb rather than the 37.3lb
Whilst not world shaking, they definitely feel faster and do exhibit the speed increase that Uukha claim over the EX1's. I saw 7fps difference between the 2 limbs at same poundage and brace height.
Even though they are a slightly more curve design than the EX1, I could still get away with the 1/2" shorter string that I use with the EX1's and keep brace at middle of recommended range
Beautiful matt finish carbon weave is quite striking in person. Photos do not do them justice.

Cons-
* They were very hard to mount. The limbs were too tight for the riser limb pocket. Trying to insert them with any force would push the entire floating dove tail bolt inwards. The limbs needed a careful sanding to get them to fit and even so were still very tight. Could be the bow but did not have this issue with my EX1's. Even though at first they were not seated fully, trying to remove them to sand did require a lot of strength.


I did some basic tests on both limbs as I swapped them over so for those interested in the numbers read on

Tools used for test
Arrow speed RadarChron (this has given me very consistent results over its entire lifetime. Always within 2fps for each draw)
Easton Digital bow weight scale tested multiple times to get consistent result (also tested against a digital luggage scale and weight was within .1lb each time)


EX1 Evo 2 38lb Medium 25% carbon construction
Draw OTF 37.3 (37.3, 37.2, 37.3, 37.1)
Chrono results 196fps, 195fps, 196fps

Took the EX1's 38's off and put the SX100 36's in without changing limb bolt setting. Absolutely no limb alignment needed as the new limbs lined up perfectly from the EX1's setting. Having read and completed Limbwalkers bow on plane test with the EX1's, I double checked with the SX100 and same riser to string gap on both sides. I did need to adjust the brace height back to 21.8cm with SX100 as limbs are slightly more curved than the EX1's. The SX100 were 23.6cm with same string.

SX100 36lb Medium 100% carbon construction
Draw OTF 34.4lb (34.4, 34.5, 34.4, 34.3)
Chrono result 195fps, 196fps, 196fps)

I needed to turn limb bolts approx 2 1/2 turns to get draw weight back to preferred 37.3lb
Draw OTF 37.3lb
Chrono result 203fps (202fps, 203fps, 203fps)

One last test I performed as I'm OCD is the poundage change for each inch of draw change. Note that this is with my original limb bolt setting on the EX1's which was about 1 1/2 turns out from mid range of the GT riser. Uukha limbs lb are rated at middle tiller bolt adjustment range.

EX1
27" 34.1lb
28" 35.9lb
28.74" 37.3lb
29" 38.1lb

Note: 1 full turn on tiller bolts = 1.5-1.6lb increase @ 28.74 draw

SX100
27" 32.5lb
28" 33.8lb
28.74" 34.4lb
29" 35.2lb

Note: 1 full turn on tiller bolts = 1.2lb increase @ 28.74 draw

Whilst the SX100 were 36lb and EX1 were 38lb, I was a little surprised that the poundage change per 1 full turn of bolts was quite different between the 2 limbs as I thought they would be closer.

I know that some ala Limbwalker will say something along the lines of if only people spent as much time focusing on their shooting as they did on their equipment but I love analyzing my equipment almost as much as I like shooing it so when i cant get out and shoot, I think!.

Obviously I've only had the SX100 for a day but my initial impression is that I'm glad i splashed on them, even if it did take almost 8 weeks to get my hands on them. They feel fast, smooth and less tiring to hold and even with the 40-50 arrows I shot last night at 18m, the poor release shots, of which there were a few, were still catching the 8/9 line which fills me with confidence that the stiffness of these limbs will be forgiving for my style of shooting

Hope this helps those that are interested in Uukha limbs but need to buy sight unseen.


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## jarda (Nov 12, 2003)

Nice review, thank you. You don't know what is the difference between sx+ and sx100? Why did you choose sx100? Thank you for the answers. I'm thinking of buying a sx + or sx100


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## DanielFZ (May 31, 2016)

This is the only difference you can see on their sight:


> It benefits from a highly refined lay-up with thinner carbon plies.


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## Timevoid (Aug 19, 2018)

Thanks for review. Great info with the chrono results  i wish i had one myself.


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## russch (Jun 15, 2002)

Enjoyed reading the analysis very much. Receiving my Gillo riser today via UPS so found it even timed perfectly for me. Will put my 30lb Uukha’s Ex1Evo2 limbs on it. I noted you mentioned 1/2” shorter string with these. This is new information to me and if possible would like to hear reasons and discussion pro and con. Considering taking the plunge on the new models. Thanks in advance 
.


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## vscarf10 (Dec 31, 2019)

jarda said:


> Nice review, thank you. You don't know what is the difference between sx+ and sx100? Why did you choose sx100? Thank you for the answers. I'm thinking of buying a sx + or sx100


All I know is that they are both 100% carbon but as DanielFZ has posted, its something to do with the carbon layup finish which I believe I read somewhere makes the SX+ limb a few grams lighter and stiffer vs the SX100.

I couldn't the justify the extra few hundred dollars between the 2 as I doubt I would notice the difference at my level of shooting


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## vscarf10 (Dec 31, 2019)

russch said:


> Enjoyed reading the analysis very much. Receiving my Gillo riser today via UPS so found it even timed perfectly for me. Will put my 30lb Uukha’s Ex1Evo2 limbs on it. I noted you mentioned 1/2” shorter string with these. This is new information to me and if possible would like to hear reasons and discussion pro and con. Considering taking the plunge on the new models. Thanks in advance
> .


When I first got my EX1’s, I put them on a WNS Motive riser but found that my standard 65” string from previous WNS limbs made my brace height very short, like in the 20cm range or under 8” which I didnt like the sound or feel of and I had to put a huge amount of twists in it to get close to the higher brace height range which Uukha states is 21.8cm +/- 10mm.

Uukha website has a string recommended length for all their limbs and had a 163.5cm string for the Curve limbs (EX1) but a standard 165cm string for the X curve so I got a 64.5” string made and was more comfortable that I didnt have to twist the heck out of the string to get my brace up to around 22cm which is where my EX1’s felt good and sounded their best even though I still couldn’t remove that residual hum/vibration no matter where brace was set.

With these new limbs, i had to untwist the 64.5” string to get brace back to 21.8cm but still left enough twists in the string and the limbs are very quiet compared to the EX1


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## vscarf10 (Dec 31, 2019)

Timevoid said:


> Thanks for review. Great info with the chrono results  i wish i had one myself.


Yeah I’m a bit of a numbers guy so the chrono tests are fun and satisfy my curiosity. With my light arrows and not so heavy draw, it still certainly feels like the bow spits them out with some force. The EX1’s also had that good speed feel about them but sound and feel on release felt more harsh than the Sx100’s.


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## Timevoid (Aug 19, 2018)

vscarf10 said:


> Yeah I’m a bit of a numbers guy so the chrono tests are fun and satisfy my curiosity. With my light arrows and not so heavy draw, it still certainly feels like the bow spits them out with some force. The EX1’s also had that good speed feel about them but sound and feel on release felt more harsh than the Sx100’s.


It will be fun to see the sight changes for 50m when i swap to my Gobi limbs and my new 255grn arrows. Will be a fun challenge between Win&win and Uukha and new arrows for 2021 setup. I should gain about 10" elevation change compared to my 290grn arrows and about 20" gain compared to my 320grn arrows.


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## j.conner (Nov 12, 2009)

Good review, vscarf10 - thank you!


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## vscarf10 (Dec 31, 2019)

Timevoid said:


> It will be fun to see the sight changes for 50m when i swap to my Gobi limbs and my new 255grn arrows. Will be a fun challenge between Win&win and Uukha and new arrows for 2021 setup. I should gain about 10" elevation change compared to my 290grn arrows and about 20" gain compared to my 320grn arrows.


Shot a few more arrows at 11m at home and set my phone’s camera on slow mo just to see arrow reaction and looks like the arrows are flexing a lot more now, so much that the tails clearance around the riser/rest/plunger is by quite a margin when compared to the EX1 which had good clearance so arrows might be on the weak side now with the extra speed coming out of the bow at same lb as the EX1’s.

Ive got room to trim if need be so will test out tomorrow and shoot some bareshafts to see what they do as my EX1 had straight bare shaft flight all the way out to 70m with a good release and landed close enough to the fletched for my level of shooting from 40m -70m.

What weight did you get the Gobi limbs?


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## DanielFZ (May 31, 2016)

Someone pointed out in the SX50 thread that the uukha limbs seem to like one spine weaker arrows than usual and my bareshaft results back that up. I thought I would need T5 (Easton) arrows but my T4 arrows are grouping better.


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## vscarf10 (Dec 31, 2019)

DanielFZ said:


> Someone pointed out in the SX50 thread that the uukha limbs seem to like one spine weaker arrows than usual and my bareshaft results back that up. I thought I would need T5 (Easton) arrows but my T4 arrows are grouping better.


My arrows are T5 but they seem very whippy now with the new limbs.
Uukhas suggesting to go 1 spine weaker confuses me as I thought you would want a stiffer shaft to compensate for the additional velocity from the limbs as weaker flexes more.

I have no issues with arrow clearance so if the arrow is flexing a lot and clearing the riser shelf very easily, wouldn't a slightly stiffer shaft be better as it will flex less which means its closer to the rest/plunger for more lineal departure And rate of flex will reduce quicker down range?


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## DanielFZ (May 31, 2016)

My 38lb SX50s are pulling around 40 on the scale with my current bolt settings. My 1914 X7s(T5) bare shaft was very left (too stiff). Went down to my 710 ACG(T4) and the bare shaft is right in the group. Haven’t tried my 1913s since just refletched them, but I imagine same results. Will try this weekend. Less stiff, lighter shaft, more distance. 

Bought some RX7s(T5) before I knew this, might have to crank the limbs all the way down to get them to tune. Will see eventually. Gotta fletch those still, been lazy.


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## Nojiri (Nov 15, 2019)

vscarf10 said:


> ... Uukhas suggesting to go 1 spine weaker confuses me as I thought you would want a stiffer shaft to compensate for the additional velocity from the limbs as weaker flexes more...


vscarf10-
The supposition that Uukhas need 1 spine weaker is not because of velocity but because of the increased torsional rigidity. When you employ a monolith (or monocoque) construction as opposed to a sandwich construction, which Uukhas (and Nika) do, you can get pretty impressive torsional rigidity, which I'm sure you've noticed. The theory is that with the increased torsional rigidity, the arrows launched by Uukhas flex less (launch strighter?), and thus, need less spine stiffness. You'll have to do the tuning yourself. When I switched from carbon foam (sandwich construction) limbs to carbon monocoque, I didn't have to change arrow spines; they tuned just fine. YMMV.

Cheers!
Nojiri


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## vscarf10 (Dec 31, 2019)

Nojiri said:


> vscarf10-
> The supposition that Uukhas need 1 spine weaker is not because of velocity but because of the increased torsional rigidity. When you employ a monolith (or monocoque) construction as opposed to a sandwich construction, which Uukhas (and Nika) do, you can get pretty impressive torsional rigidity, which I'm sure you've noticed. The theory is that with the increased torsional rigidity, the arrows launched by Uukhas flex less (launch strighter?), and thus, need less spine stiffness. You'll have to do the tuning yourself. When I switched from carbon foam (sandwich construction) limbs to carbon monocoque, I didn't have to change arrow spines; they tuned just fine. YMMV.
> 
> Cheers!
> Nojiri


Thanks for the explanation. It’s still confusing to me as I understand more rigid limbs push the arrow straighter and these Uukhas are certainly rigid but if theres additional velocity also involved ( in my case extra 7fps at same lb as previous limbs), wouldnt it stand to reason that you need a stiffer staft so the forward force of limbs and string dont create additional bending on the shaft at release and hence slower arrow recovery?

I took some slow motion footage of arrows flight today to check centre shot and did need to push plunger out from riser a touch more than the EX1’s but there was also what seemed like a lot more flex all the way down range for both fletched and bare shafts.

Heres a link to the slo mo. One is barehsaft and other is fletched. Is this excessive whip or considered normal?

Select .25 playback speed for better vision of flight.


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## nex667 (Sep 1, 2018)

Can't help interpreting the videos, sorry. Regarding arrow spine: Uukha suggests to use arrow manufacturer's spine tables.


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## Nojiri (Nov 15, 2019)

vscarf10 said:


> ...It’s still confusing to me as I understand more rigid limbs push the arrow straighter and these Uukhas are certainly rigid but if theres additional velocity also involved ( in my case extra 7fps at same lb as previous limbs), wouldnt it stand to reason that you need a stiffer staft so the forward force of limbs and string dont create additional bending on the shaft at release and hence slower arrow recovery?...


That's exactly why you need to do the (bareshaft) tune yourself. There are lots of theories out there, and as far as limb poundage/spine, you can't just go off of charts, even arrow mfg's charts, since there's so much variance in equipment. Do the bareshaft tune at 30m, three fletched arrows and three bareshaft arrows, shot alternately. Your bareshaft tune trumps all the theories out there, right?

Cheers!
Nojiri

PS. Cool Youtube videos, btw. Shaft flex doesn't seem all that unusual to me. How did they tune?


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## Timevoid (Aug 19, 2018)

vscarf10 said:


>


Hmm, got my age set in Youtube but still locked out to watch them. And i'm not going to upload my all my credit card info or ID/passport info to google just to watch the video :S.
Anyone else got same issue ? 

*update Got it working on my phone. So its solved.


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## DanielFZ (May 31, 2016)

Those seem to be wiggling as arrows do. More or less than normal I cannot say. Rarely see that angle.



Nojiri said:


> Your bareshaft tune trumps all the theories out there, right?


Well at 18m my 1913s are also sending the bare shaft left, but not as left as the X7s were going, so I need to mess with my plunger more to fix that, but I don't want to change my 710s tune so for now I'll just say I believe Nojiri is correct. Charts are one thing, Bareshaft is perhaps the most accurate thing.


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## Nojiri (Nov 15, 2019)

DanielFZ said:


> ...Well at 18m my 1913s are also sending the bare shaft left, but not as left as the X7s were going, so I need to mess with my plunger more to fix that, but I don't want to change my 710s tune so for now I'll just say I believe Nojiri is correct. Charts are one thing, Bareshaft is perhaps the most accurate thing.


DanielFZ-

Do you have the ability to tune at 30m? I think that's a more suitable distance to tune because at 18m, your arrows might not have enough time to straighten out... Unless you're purposely wanting to tune for 18m...

-Nojiri


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## vscarf10 (Dec 31, 2019)

Nojiri said:


> That's exactly why you need to do the (bareshaft) tune yourself. There are lots of theories out there, and as far as limb poundage/spine, you can't just go off of charts, even arrow mfg's charts, since there's so much variance in equipment. Do the bareshaft tune at 30m, three fletched arrows and three bareshaft arrows, shot alternately. Your bareshaft tune trumps all the theories out there, right?
> 
> Cheers!
> Nojiri
> ...


I did bare shaft out 30m, 40m and even a few out to 50m. At 30m and 40m they were a few inches right of fetched with fletched in the gold.

At 50m it was more me than the arrows as some bare shafts landed in the group which was a little low and catching 8-9 line on left of center and other bare shafts were 3-4 inches left which could still be center shot related or it was the breeze coming over shoulder from right to left pushing me and my light arrows). Even shot one out to 70m and it landed 1 foot left of 3 fletched which were in the 8 ring left of center.

I just can't get past how much flex the shaft has at release as there's plenty of tail clearance past the riser/rest which is why I though stiffer might be better to reduce the amount of buckling into the plunger at launch.


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## vscarf10 (Dec 31, 2019)

Timevoid said:


> Hmm, got my age set in Youtube but still locked out to watch them. And i'm not going to upload my all my credit card info or ID/passport info to google just to watch the video :S.
> Anyone else got same issue ?
> 
> *update Got it working on my phone. So its solved.


Not sure whats going on there as its my first ever upload to YouTube but they found my slo mo arrow flight not suitable for younger audiences. I'd hate to see what they consider to be really offensive material 

* Update YouTube have changed viewing to all ages as they don’t find my arrow flight offensive anymore 

Also for those interested, with same lb OTF and exact same arrows, there was a 5mm difference in sight elevation between the SX100 and EX1's at 70m.


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## DanielFZ (May 31, 2016)

Nojiri said:


> Do you have the ability to tune at 30m? I think that's a more suitable distance to tune because at 18m, your arrows might not have enough time to straighten out... Unless you're purposely wanting to tune for 18m...


I'll try it next weekend. I was spending quite a bit of time shooting at 30m this weekend with good results. Backed up for a special target at 40m (with a purely guessed sight mark) for one end. I don't remember sending a bare shaft out at those distances to see where things were, the groups were good so I was happy.


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## Nojiri (Nov 15, 2019)

DanielFZ-

If it’s the first time for you to shoot bareshaft ends at 30m, you might want to have someone spot your arrows for you. If you happen to send a flyer out that misses the target and you don’t see where it went, it can be a real pain trying to find a bareshaft in the grass, haha.

Also, do you know how to tune for high and low groupings? That can give you a clue about your nocking point/ tiller settings.

Cheers!
Nojiri


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## DanielFZ (May 31, 2016)

Oh yeah, I know how to tune, I'll still waiting for things to settle in before tying on the nocking point. I'm still playing with brace heights to get best tune so things are still settling in.

Now that you mention it I think I did look at my bareshaft and decided not to shoot it since I was worried about finding it in case it missed the bail.


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## DanielFZ (May 31, 2016)

So I did 30m bare shaft today. Groups where fairly good when I did my part, bare shaft was low, but aligned vertically with the group. The nock point was a bit high and brace height was good so I just moved the nock point down to bring it in. Think I can safely tie on next time and get rid of the metal nock I’ve been using so far.


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## Nojiri (Nov 15, 2019)

DanielFZ said:


> So I did 30m bare shaft today. Groups where fairly good when I did my part, bare shaft was low, but aligned vertically with the group. The nock point was a bit high and brace height was good so I just moved the nock point down to bring it in. Think I can safely tie on next time and get rid of the metal nock I’ve been using so far.


Sounds good, DanielFZ. Do you know how to balance tiller with your nocking point height? Conventional wisdom says you'll want tiller and brace height to match (i.e. 5/32" positive tiller / 5/32" nocking point, etc). All that is not just to get your arrows to tune vertically, but to get the most level flying arrows that you can.

Cheers!
Nojiri


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## DanielFZ (May 31, 2016)

Never gone that far. I focused on getting a tiller for in an acceptable range a few weeks ago that gave decent sound. I haven't paid attention to it since then, but I should check it and confirm it's in a good place. Gonna have to check on that. Thanks for the info.


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## vscarf10 (Dec 31, 2019)

Nojiri said:


> Sounds good, DanielFZ. Do you know how to balance tiller with your nocking point height? Conventional wisdom says you'll want tiller and brace height to match (i.e. 5/32" positive tiller / 5/32" nocking point, etc). All that is not just to get your arrows to tune vertically, but to get the most level flying arrows that you can.
> 
> Cheers!
> Nojiri


How do you measure your nocking point?
Say you have two tie on points and the gap between the two is = the width of the nock with a little room for nock not to get pinched, do you consider NP height to be the underside of the top nock, on top of the bottom nock or right in the middle of the two as that can possible be around 6mm difference depending on nock width


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## Nojiri (Nov 15, 2019)

vscarf10 said:


> How do you measure your nocking point?
> Say you have two tie on points and the gap between the two is = the width of the nock with a little room for nock not to get pinched, do you consider NP height to be the underside of the top nock, on top of the bottom nock or right in the middle of the two as that can possible be around 6mm difference depending on nock width


I've always heard it referred to as the bottom of your arrow rest to the bottom of your nocking point (top of your bottom nock). With that, it's easy to measure with your bow square since the bottom of square's horizontal bar sits on your arrow rest when the square is clipped to your bow string. Then, wherever the bottom of your nocking point is, that shows on your bow square guage, and that's your nocking point height. I always tie my bottom nock on first, then nock an arrow, then tie my top nock on very snug. Don't try to just measure that and tie your top nock. You do NOT want any vertical play in your nocking point when your arrow is nocked. Any slop there is magnified at 30m, 50m, 70m.










I mentioned that "conventional wisdom" says your tiller (positive) should match your nocking point height. There are varying opinions on how to determine ideal tiller. Jake Kaminski determines his by how the string makes his fingers feel at full draw:






I have my tiller match my nocking point height and my fingers feel fine. Some people adjust their tiller so that when they are at full draw their sight feels level. If you do that, make sure you do it with your full stabilizer setup. In any case, just be aware that tiller settings and nocking point go hand in hand, and their correct balance should have your arrows flying as level as possible and vertically tuned.

Cheers!
Nojiri


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