Iʻve been progressively chopping my stabilizer down for pump foiling which has sparked a lot of thinkingn about them. I took it out in the surf the other day which also was an interesting disaster. I donʻt really need a huge breakdown of these, but if anyone can confirm/clarify, it would help. The way Iʻm thinking about stabilizers is so different from when I was learning.
The “lift” of a stabilizer is kind of an illusion. Itʻs more of a counterbalance on the front wing to smooth out pitch inputs. It pulls down, forcing the front wing into an upward (lifting) pitch angle.
A larger tail shimmed flat has less drag, but does it maintain the low-end “cushion” (margin for error) when pumping that it would without more angle of attack? It feels like it does.
The smaller the stabilizer I use, the more low-end it feels like my wing has. I suspect itʻs just that I have less drag and an easier time staying above stall speed.
Big wing tiny stabilizer in the surf was bad. Careful yaw turns were fine, but if I roll it over, thereʻs no “grip” and it just flops down. I suspect the rate of increased tail size provides more “grip” in roll than increased fuse length.
Does increasing fuse length have a higher/lower increased rate of drag than increasing tail size?
Increasing tail size will provide more stability and margin for error in roll/yaw, but increase upward pitch influence. This was a huge mistake when learning prone and trying to get my pitch under control.
Increasing fuse length will smooth out pitch inputs, but is slower to smooth out roll/yaw compared to increasing tail size.
Haven’t played with this a lot yet, all these years I’ve been riding smaller stabs for efficiency and maneuverability, but lately I’m forcing myself to go big and kinda liking it? Recently I was riding Hood River event site swell on Code 1075r+175ar (unheard of combo? my wife’s learning setup) and having a blast. I think bigger stabs give you more to lean into and push against, too small stabs let you “slide out” the foil too easily and break flow.
I’m curious how big stabs shimmed for minimal pitch feel, I imagine less front foot pressure but still some element of pitch stability, will give that a try.
I’m not sure what you consider “big wings” and “small stabs” but I ride 1950 / 1750 / 1350 front wings with the same 50 sqcm stab and I roll the hell out of 'em with no issues. I think this is front wing dependent.
I was on a 1300s with short fuse and 120r cut down to 280mm. It was about chest high where that wing seems to start locking in more, but the tail was defimately loose.
Code stabs are kind of weird because there are no truly small low ar tails. 142 is still pretty big. I’ve been riding the crisp 110 with big code foils. (1130, 1250, even the new dumb pump foil) And it’s been awesome. The r tails lock up even when chopped
The biggest influence of the stab is in how it changes the rest of the system. More stab downforce(bigger stab, more down angle, more lever-fuse) means the center of lift moves forward, meaning the whole foil is farther back in relation to your center of mass (this is true wether you move the foil or change your stance or think your not changing either - your stance is changing even if your don’t know it). This is the primary stabilizing process
I use custom swept back stabs with a lot of chord that I pitch down. Lots of pitch stability is crucial for what I am doing. Feels way better than any traditional stab in the whitewater and on the bottom turn, and especially on vertical take offs. Is it slower? Yes. Is the glide worse? Yes.
Regarding number 2 I disagree. A larger tail (measured in surface area) will have greater drag than a smaller foil regardless of the angle attack (within a few degrees) due to less wetted surface area. It’s nearly a 1:1 reduction in drag when you reduce surface area (e.g. 25% less surface area is 25% less drag). In addition smaller stabs generally have a higher aspect ratio which also reduces induced drag. So a larger stab trimmed at a neutral angle of attack will have more drag than a 25% small stab at 1.5 degrees angle of attack.
I agree with your whole reply. Sorry, I think I wrote that one in a confusing way. Hereʻs a correction.
A tail when shimmed flat will have reduced drag. If itʻs a large, forgiving tail, it will maintain a lot of itʻs low-end “cushion” (margin for error) even without the angle of attack.