The speed and performance of your limbs is completely dependent on preload string tension at brace that stops mass weight of the forward limb travel clean and transfers the stored energy to the shaft. Your actual limb travel distance plays a big part in this too….
I only find the string tension part partially true... With some designs string tension and performance run hand in hand only so far... Once you get up to a certain performance level other factors like how the limb is bending (that may include your limb travel you talk about) and delivers that arrow become more crucial than string tension... I have built bows with a lower (percentage wise) string tension that were faster than a bow with higher string tension...
I too thought the more string tension the faster the bow... Until I built a bow with an amazing amount of string tension but was slower than my other bows... It was an eye opener... I could write a couple of chapters on Performance and how ST and DFC's are related to it, but on this site most are uninterested in the science and numbers part of seeking top performance... Matter of fact in other bow making groups and sites I have found only one person that has an accurate DFC and is not sure how to use it or understand it... And no one wants to know either...
I guess because it is homework and no one likes to do their homework...
[/quote]
I’ve read this post of yours several times trying honestly to comprehend your analogy of performance and how string tension and DFC charts are related to it.
A DFC chart is just a chart showing pounds per inch through the course of the draw. Just changing the length of a string on a bow changes both the string tension and the DFC chart a certain amount.
I’ve never seen a bow with lower string tension and preload that exceeded performance levels of higher preload bows using a 10 gpp @ 28-30” draw base for testing. The only way I could see this happening is in a heavy draw weight D shape long bow with low ST using extremely heavy shafts like a 60@28” shooting a 1200 grain shaft. The mass arrow weight and momentum build up with the time on the string in a longer forward limb travel mitigates the string tension at brace….. this same bow would not do as well with lighter arrows.
But you are absolutely right about most guys are not much interested in spending time with the charts and numbers parts of bow building. They would rather hone their craftsmanship skills and produce some nice finished products. Others like yourself are obsessed with the testing and documentation more so than producing a finished product. I can appreciate that too. Mad scientist mode is fun from time to time….
Id love to see a photo gallery of your finished products sometime Shredd. Maybe you could post a few reviews you have received from happy customers too. I’d especially like to see this bow design that has higher performance with lower pre load and the specs, in all its glory. Kirk