I am still playing with and enjoying shooting my Vertex riser. But during this spell of wet weather, which is curtailing my shooting, I have been evaluating the suggested brace heights quoted by KG and my Uukha limbs. If I set the brace height as suggested by KG (which is measured from the back of the riser not the grip) to 10" and then measure the brace from the deepest part of the grip I get a brace height that is nearly 1 1/4" lower than that quoted by Uukha! Obviously if I set the brace lower the difference becomes more significant. I do not want to damage my limbs and I would like to get a difinitive solution. I appreciate mixing and matching is not ideal and riser geometry plays a part in the bow setup.
KG Vertex Riser and Uukha Limbs Brace Height
- Thread starter albatross
- Start date
I have four sets of Uukha limbs on various risers ranging from Border 19" Covert Swift to 25" Smartriser and from overall bow length from 58" to 68", and have always found that they work pretty well following Uukha recommended brace height according to the bow length. Use the measurement to the throat of the grip. Start at the given measure and you can go +or- 10mm. Mine have always ended up within a couple of millimetres of the given figure and on two of the bows I use the are at the given figure.
Thanks for the reply Geophys2. I had decided to go with the Uukha brace height as I figured I would do less harm to the rigid carbon riser than the flexible limbs by using the Uukha limb brace measurement. I have made a new string, which with 20 twists, gives me the brace - 10mm. I will go from there.
I don't think you can beat sound tuning for brace height, I would start at the lower Uukha recommended brace height and shoot the bow, add a couple of twists and shoot again, and keep going till you find the two quietest brace heights, there is usually one below and one above the "middle" brace height.... Then just stick with the one that feels best....
Today I had a shoot. I tried the Uukha brace recommended height. I started at 210mm and went up twisting the string until it got to 260mm! The groups were rubbish and the bow sounded 'not nice'. I started to untwist the string and lowered the brace to about 190mm and I noticed an improvement in group size and bow noise. So on Sunday (if the weather holds) I will set the bow up with the KG Vertex brace range and see what happens! This is a 70" bow.
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My last shooting session did not go well. I set the brace at the KG suggested range which resulted in a very low brace (at least 70mm below recommended with long limbs 70") when measured from the throat of the grip. So it is back to the drawing board for the next session during which I will set the tiller to '0'. The brace at the KG height (9 1/2" with med limbs 68" bow) and start with an adjustable nocking point, shoot some arrows and assess the results. I should get some positive result by the end of a few ends to give me some starting point. It is strange that the Vertex riser is not listed on their bow information page!
Sorry, I can't follow you here. You say the KG height for 68" is 9.5", ie, 241mm, measured to the Back (ie the "front") of the bow. Back in the day, my old 66" Marksman bow was about 10.5" to the Back of the bow. I would double check the KG information very carefully. As Steve Stills said, "There's something happening here, and what it is ain't exactly clear."
Thanks for the reply. As I stated there is no information on the KG site regarding the Vertex riser. So I had to make an educated guess using other KG riser models to get a starting point. Your marksman may have a different deflex to the vertex resulting in the brace difference. I made a string that showed about 25mm of string groove when the bow was braced which equated to the suggested starting brace height for another 68" model of KG riser. This is a starting point and may well alter as I test the bow for the best brace height. As mbaker74 suggested I started with the Uukha recommended brace but it was terrible to shoot even as I increased the brace height. Hence the new approach.
As promised here are my results for shooting yesterday. It was cold so not the best of days for shooting! BUT as I released the first arrow I immediately noticed an improvement in the bow! There was no 'out of sync' from the limbs - they were much quieter than with the previous setup. I set the tiller '0' nocking point at 4mm which I had to adjust, as expected, to 6mm to get the bare shafts level with the fletched group. The brace height was <> 9 1/2" and the group was acceptable. I gradually increased height and finished with 250mm (10"). I have a quiet bow and much more pleasing groups. However I have 50+ twists in the string, so I will have to make another slightly shorter to get about 20 twists for brace height. I don't think the limbs will be harmed by the low brace height when measured from the grip as they sound so quiet. I'm really pleased I made the change in setup. Roll-on the summer.
May I ask why zero tiller?
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Thank you for both your replies.
dvd8n. The 10" brace height is within the range for KG bows of the same length. As I have previously stated there in no information on the KG site for the Vertex riser. For the cost of this riser I would have thought there would be some guidence. But there again I did not even get an A4 printed sheet with information it! The arrows are the recommended spine according to the Easton chart.
Timid Toad. I have tried a range of '+' and '-' tillers with this riser. This is the only one that gives me a 'quiet' bow. Rick McKinney in his book recommends '0' tiller and then tuning with nocking point adjustment. Vitorrio also says set it to zero. It works for me, maybe my shooting style suits it.
dvd8n. The 10" brace height is within the range for KG bows of the same length. As I have previously stated there in no information on the KG site for the Vertex riser. For the cost of this riser I would have thought there would be some guidence. But there again I did not even get an A4 printed sheet with information it! The arrows are the recommended spine according to the Easton chart.
Timid Toad. I have tried a range of '+' and '-' tillers with this riser. This is the only one that gives me a 'quiet' bow. Rick McKinney in his book recommends '0' tiller and then tuning with nocking point adjustment. Vitorrio also says set it to zero. It works for me, maybe my shooting style suits it.
That sounds a lot more reasonable
