Kiteforum.com

How strong does a bar have to be? If unhooked and boosting, it must me very strong of course, to handle the full force of the kite and rider weight. However, if always hooked in and mostly foiling, how strong does it really need to be to handle the pull of the steering lines?

I’m considering shaping/carving a custom wooden bar and glassing it for novelty and DIY fun, and maybe learning to splice lines, etc. Assuming the CL and safety system is modern and functional, are there any potential problems I may not have considered?

Thanks in advance.

center lines take up to 3 G's but pass through the bar, that can be up to half a ton loaded on the two centers. Steering lines typically take about 1/4 of that at max load, so up to 300 pounds or 140 kg. Remember the center lines pass through the center so there's no force from the centers lines transfered to the bars unless of course there's some sort of death loop. The control bar has to be strong enough that a human's grip will fail before the control bar snaps. You typically want some sort of safety margin so I would design it to take 800 pound or 360 kg. a simple wood bar is strong enough to take this amount of force, the trickiest part is making sure the center of bar is strong despite having a hole in it. Typically bar manufacturers make the center of metal and the bar itself from fiberglass. Not much point in designing a bar that can take much more than 800 pounds / 360 kg that is more than enough to be more than anyone's grip

Regarding foiling, it depends on the style you ride - racelike, jumping really powered, or freestyle/waves ?

If the latter, you dont have any significant load on the rear lines really, and I would not worry about it.

The most load then, on the rearlines, will be when you loop the kite, and here you got your hand on the loaded side of the bar, thus no stress on the centre of the bar

PF

Imagine the chaos of a snapped bar

Blackrat wrote: ↑

Thu Jan 18, 2018 7:19 am

Imagine the chaos of a snapped bar

I imagine it will most likely snap in the centre. Which means both steering lines go slack.
Release to single front line and self rescue.
Or did I miss something?

rynhardt wrote: ↑

Thu Jan 18, 2018 10:02 am

Blackrat wrote: ↑

Thu Jan 18, 2018 7:19 am

Imagine the chaos of a snapped bar

I imagine it will most likely snap in the centre. Which means both steering lines go slack.
Release to single front line and self rescue.
Or did I miss something?

Agree, I see no problem really

You probably dont even have to release to a line if hydrofoiling, as it is fully depowered now if it snaps and usually very low power for starters, so it will just go in the water without power and you can wait till drifted ashore without risk of tangling in lines

But of course, if there is no floaters on the bar, it might get messy if one of the ends tangles into something on the bottom

Peter

rynhardt wrote: ↑

Thu Jan 18, 2018 10:02 am

Blackrat wrote: ↑

Thu Jan 18, 2018 7:19 am

Imagine the chaos of a snapped bar

I imagine it will most likely snap in the centre. Which means both steering lines go slack.
Release to single front line and self rescue.
Or did I miss something?

I remember a local kitesurfer had his bar (glasfiber one..) break in two and seriously wounded one of his hands in the event. Took him ages to get back on the water, functionality of the hand never got back to 100%.

So chaos due to a snapped bar? Yes...

^
Uhm,that mighthappen to any bar.

I mean, look at Nico, #1 racer and his bar. Just a carbon tube. And man, that guy can jump.

My next bar will be a carbon tube, ultra light. I would rather be hit with an UL bar into my eye than any other bar. As I was.

And, a carbon tube will float if closed right.
Win-win.

D.

My only experience with a bar breaking was very chaotic. The bar broke at one end during boosting, so one steering line went slack while the other stayed attached to the bar. Result was the dreaded death loop until I could gather my senses and hit the quick release. I'd like to avoid that experience in the future, if possible.

downunder wrote: ↑

Thu Jan 18, 2018 3:47 pm

My next bar will be a carbon tube, ultra light. I would rather be hit with an UL bar into my eye than any other bar. As I was.

And, a carbon tube will float if closed right.
Win-win.

D.

I'm interested in this project as well. I can't stand the integrated puffy EVA bar end floats that are in style today. 20 mm wrapped CF tubes are readily available on eBay. My question is how to address the hole in the bar center with a bushing so the centerline does not prematurely wear. Simple bar end winders might also be nice. I would imagine filling the bar with a polyurethane foam for flotation.