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Note: The most-used sizes of fiberglass and many of the carbon fiber rods and tubes used in most of my medium sized kites are no longer being made for retail sale in small batches. I now have no old spars left for Whirlwinds, Wildcards, R7's and Troopers; no spars for the CC345 (Carbon Classic) and the LC345 (London Classic); soon there will be no more spreaders for the R6.
The search goes on for substitutes.
Prototypes are being tested and modified, but frame stock for testing has been used up. I have found first one, then another size and spar combination that worked, and one or two that worked dishearteningly well. But, after months of experimenting, those wing spars, made from our old stock, were found to have been discontinued. And later on, so were some of the center spines. As of mid-May '17 my most recent prototypes have been relegated to the shelf by yet another round of discontinuations affecting both wing spars and center spines. Next time the list may include both Clippers, although the Clipper S and the GPX may be morphed into one; at least temporarily. With no spreader stock for the R6, it may evolve into a new R7 replacement, while the R7 may grow into a new larger version alongside larger versions of the Whirlwind and Wildcard, if CFP (the old Woolmer Forrest Composites) continue doing their 5.5mm thick-wall pull-wound carbon tubing. Costs for testing all these new frames are prohibitive, so it may take some time to zero in on a scale, i.e. finalise the new size, which is currently at +2% relative to the standard Whirlwind, using RBJ's discontinued unidirectional 5.5mm thick-wall tubing (used in the Clipper S). Meanwhile, a new smaller range (by -4%) is just about ready to be developed to a beta stage. This will include the Whirlwind, Wildcard and R7. Other spar materials that showed promise on paper have been rejected, for instance a new 6mm spiral wound fiberglass, which is just too bendy compared to our original 6.35mm unidirectional tubing, would require drastic down-scaling. Suitable replacements for Trooper parts may never be found.
Almost unbreakable 5mm carbon rod may ultimately be the substitute of choice in the Whirlwind, R7, and Wildcard. Even 5mm carbon rods are quite expensive compared with their original pulltruded fiberglass. The two types of 6mm fiberglass tube currently available — one spiral wound, the other pulltruded — are both considerably more flexible than 5mm carbon rod, so those three kites will need to be scaled down a certain percentage (probably 4%) in overall size to maintain the right level of rigidity for a decent wind range.
5mm carbon rod was the closest to the original spars in my test to measure flexibility of spars by measuring deflections — all the other the spar candidates would have required considerably more down-scaling, and the 5mm carbon rod's -4% already looks small. On the other hand, the 2% increase for 5.5mm carbon tube spars might have to be increased for the latest 5.5mm pull-wound carbon, though it may be only +2 to 4%. What I know for certain is that +8% is too much; the kite flies beautifully but because the carbon frame is so light it's impossible to control when the wind drops. It won't level out the way a good kite should. It just drifts randomly, while the line drops out of the sky. Hm-m-m-m. Maybe it needed a heavier spine. So I made new ones by putting 3 or 4mm rods down the inside of existing spines, but have not yet tested them fully. They all appear to work in normal conditions. It's a matter of striking a compromise: finding the sweet spot between balance, performance, and handling, over the widest range of wind conditions. One thing that works one day, might not work the next, and so on and so on. Unfortunately costs can rise to ridiculous heights doing this.

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