Gillo GT Riser 2019

Stretch

Member
High preload would suggest that you allow the brace height to stay the same along with the extremes. I suspect that the best brace height will vary at the extremes of adjustment. So the shape of the limb is about the same but the positioning of the limb changes a bit relative to the geometry.

It would be a compromise but then every bow is a compromise so difficult to guess at the outcome.

I think what you will find is that some limbs will work better at the extremes and these will probably be limbs with softer FD. Although it could be argued that stiffer F/D limbs might work better in the lighter settings! But the joy of the design is that your investment in quality limbs will last most archers from improver to county and back to dotage if they choose to do it.

If someone would like to buy one and send me a bunch of limbs I’d be happy to sample and report back :p As I know Gillo will have tested the hell out of this they may have more detailed guidance to release at some point.

Stretch
 


dottorfoggy

Member
27" 1450g
29" 1550g
31" 1650g?
They have a range from 19" to 31"
As already mentioned, they are quite heavy and I can see the most advantages for barebow shooter.
My nano max 27" is 1350g and is already a heavy riser for me and shooting just with a total 150g weight on stabs, I don't think I can shoot with something heavier.
But I'm curious to see one someday.
 


Stretch

Member
My Axis was around 1400g - then I had a decent stack on the rods. Around 15oz total. It was great as long as I was shooting 5+ times a week with decent volume. As soon as I had drop off it was a problem. I just couldn’t get it to feel the way I wanted with light stabilisers.

I really like the 1250 -1300g range. It always seems to give a riser that feels inherently stable but light enough to add a moderate stabiliser setup and not feel too heavy when you have to take time out. Equally with modern stabilisers you can mass up to pretty much any crazy weight you like if you are that way inclined.

But still! I’d seriously think about the GT but if I had to buy mail order I’d not roll the dice on that much weight.

Stretch
 


LionOfNarnia

Supporter
Supporter
Don't 'standard' ILF risers have around +/- 10% adjustment anyway?

If so the 30% (+/-15%) of the Gilo ain't that much of a big deal, is it?

...or am I missing something?
 


Rik

Supporter
Supporter
Don't 'standard' ILF risers have around +/- 10% adjustment anyway?

If so the 30% (+/-15%) of the Gilo ain't that much of a big deal, is it?

...or am I missing something?
"standard" handles have, perhaps, a total of 10% adjustment (+-5% on a Hoyt). So it's nominally 3x the range.
 


Whitehart

Well-known member
The Earl Hoyt HDS(ILF) draw weight adjustment was originally developed so that you could get a better arrow match by making tweaks to the draw weight.

Standard ILF 10% or +/- 5% on some is not always possible because of the adjustment and detent angle - moving the limb bolt in and out. Limb butts are not all made equal some are thicker than others, so the range of adjustment can be limited.

Remember ILF is not a standard, in the way standards are normally developed and maintained every manufacturer has their own ideas how they think it should work within certain design boundaries.

By pivoting the whole pocket the limb sits in the pocket in the ideal position (a constant position that does not change as weight adjustments are made). Making it easier to set up the bow, keep limb/bow stability and reduce limb flutter etc at the extremes high and low draw weights.

The 30% adjustment means that archers can move up and down the draw weight range with less compromise of conventional ILF adjustment, we read on here about injuries etc this riser allows a significant drop of draw weight yet still allows the bow to perform and get arrows (right spine) to fly well. It also gives options to increase draw weight and again perform as the bow should.
 


geoffretired

Supporter
Supporter
It seems to me that altering the pockets on the riser is a better way to adjust draw weight than altering the limbs in the pockets.
No one says you have to use all the possible adjustment.
It's a bit like compound arrow rests. They can have a centre shot range of well over 10m.m. but that is just a way of getting the rest close to centre on many different risers. Once fitted to a riser the likely range used will be far smaller than 10m.m.
 


chuffalump

Member
If it became ubiquitous then maybe the design of limb butts would change too. No need to design a limb that can pivot. No need to narrow the notch section to allow the movement.
 


geoffretired

Supporter
Supporter
If it became ubiquitous then maybe the design of limb butts would change too. No need to design a limb that can pivot. No need to narrow the notch section to allow the movement.
Sounds like a good idea.
 


Hawkmoon

Member
High preload would suggest that you allow the brace height to stay the same along with the extremes. I suspect that the best brace height will vary at the extremes of adjustment. So the shape of the limb is about the same but the positioning of the limb changes a bit relative to the geometry.

It would be a compromise but then every bow is a compromise so difficult to guess at the outcome.

I think what you will find is that some limbs will work better at the extremes and these will probably be limbs with softer FD. Although it could be argued that stiffer F/D limbs might work better in the lighter settings! But the joy of the design is that your investment in quality limbs will last most archers from improver to county and back to dotage if they choose to do it.

If someone would like to buy one and send me a bunch of limbs I’d be happy to sample and report back :p As I know Gillo will have tested the hell out of this they may have more detailed guidance to release at some point.

Stretch
If you imagine taking a pair of limb that are sitting at a 10 degree angle to the riser and then wind them in so they are at 5 degrees, yes as you say the brace height will go up but even if you put it back the limbs will still have more preload just to get the same separation between the string and the riser. If you hold your arms up to make a "Y" and imaging a string stretched across them (say just touching the top of your head),then bring them down to make a T, you will see that you would now need to bend (pre-load) your arms to get the string back to where it was.
 


JohnK

Well-known member
Adjustable limb pockets are a compromise solution: the advantage is that they allow small tiller adjustments and a modest draw weight adjustment for tuning. The disadvantage is that you don't have a complete bow that has been tillered so the limbs work at their best by the bowyer.

It's pretty simple to go from that to understanding that a riser that offers *more* adjustment is going to result in limbs operating even further outside their normal parameters.

Now, I'm not saying that this stops you tuning the bow with a suitable bracing height change or other modifications, but it does mean that towards the extremes of adjustment the limbs will be operating outside the parameters the bowyer expected when they tillered them in the first place.

It'll be interesting to see what the early adopters experience and what their reports are.
 


JohnK

Well-known member
I also note that back in the early days of the Sagittarius Archery Blackboard, there were many people who spoke out against straying from Earl Hoyt's geometry by putting more recurve into a limb or less deflex in a riser. They had a point: if the materials remain fundamentally the same, Earl's geometry gives you a great compromise between speed and stability. Now, with more torsionally rigid and light carbon materials, you certainly can enhance a recurve and keep it stable. However, if you massively change the angle that limb enters the bow... well then you're into new territory.

As I say, I await developments with interest :)
 


Timid Toad

Moderator
Staff member
Supporter
Fonz Awardee
Ironman
Do they need to care? Unless they are producing limbs themselves, it's up to individual manufacturers to define whether their limbs are designed for the conventional +/-10% or can withstand a greater amount of stress.
Several risers out there are harsh on limbs because of their geometry. Some manufacturers make suggestions as to what limbs may work but others don't.
 


JohnK

Well-known member
I'm sure they have tested it, but to test for every draw length, limb length and draw weight variation - not to mention every brand - is not something I'd expect them to have done. That's just unrealistic, especially for a small manufacturer.

To be absolutely clear, I have no axe to grind here at all. I'm just interested to see how people will get on with such a large adjustment range and effective change in bow geometry.
 


Whitehart

Well-known member
Having now had a chance to shoot a riser (albeit RH...) with uukha limbs across all adjustment extremes, here are my initial thoughts.

Firstly, the easy bit with the normal curve, the limbs behave well across all adjustments, little limb flutter, which with more time could be settled down with minor adjustments to Tiller BH & NP.

With the extreme curve models: The testing did not show up any issues.

And neither did I see(at the fully wound in position) the temporary collapse of the structural integrity of the limbs in the belly region as demonstrated on Facebook, with some laminated limbs that to be fair can happen even at the extremes of current ILF adjustments and with some riser geometry.

However - Because of the way extreme curved limbs are designed to work I would not suggest winding the limbs in (increasing draw weight) further than you would with a current ILF bow, although there appears to be no issues going with a lighter draw weight.

ILF does have an efficient working range and going outside of these does have it's compromises, like ILF in general. Whilst the range of draw weight is a feature and a USP, I would not shoot this riser solely because of this, but for other reasons - how it feels to shoot, its looks, build quality/finish, balance, options that can be fitted to get the feel right and the way the limbs fit and adjust in the pockets.
 


Emmadragon

Supporter
Supporter
My Smartriser has a very neat system where you don't have to undo tiller blots in order to adjust; you just turn what they call the 'Quickclick disc' (which is effectively the tiller bolt).
After every 90° turn, there is a click to tell you that you've achieved the next position. There are 28 possible turns in the system, with a ± value of 0.05% of the limb poundage each way. It's not possible to unwind it to an unsafe position, as it is with normal tiller bolts.
So from the zero position, which is in the middle, on my 26# limbs, I can go down to 25.818# or up to 26.182#. It's a really small range of adjustment on a low poundage set of limbs, but obviously the variation is greater on a higher poundage.
With such a small range of variation, it's interesting to see another Italian manufacturer that's gone in completely the other direction.
I will say, though, that since I put some high quality limbs on it, it's interesting that almost 26# is substantially easier to draw than 22# was on an entry-level set-up. Much smoother, with no stacking at all.
 


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