Pulleys on kites

[alford]

Thought this subject needed its own thread. Seems like this is a hot topic. I have Rallys and they don't have pulleys. It's a good kite but far from perfect, too much bar pressure for me at times and big sizes are heavy. Do pulleys gaurentee lighter bar pressure? I'm inclined to guess no.
By nature I'd say less is usually better, no pulleys if possible means less to go wrong. Now that we're talking about it, seems like most kites have them, in fact most of the top selling kites have pulleys so I'm inclined to believe it's not lazyness on the designers part. North Rebel, Neo and Evo, Core kites have them, I believe Fone Bandits, Naish Pivots and Airush kites have them too among many others.
Of course some really good kites have none, Ozone Enduro (maybe all Ozone?) Slingshot to name a couple. Not sure if Cabrinha uses pulleys or not, couldn't find any information after a brief visit to their website.
Anyway, the goal of this topic is to help understand which kites use pulleys and why and which don't and why.

[rynhardt]

I hope I can explain without pictures, so here goes..
The supported leading edge forms a certain arc at say 10 degrees angle of attack. At any other AOA the arc will look slightly different.
With a fixed bridle with 3 attachment points or more, all the bridle lines can share the load equally at only one arc shape (AOA). Any other AOA will see at least one bridle line become slack.
With pulleys this doesn't happen.

How exactly this affects the kite will probably depend on many other factors.

[iriejohn]

Interesting topic.

I had Rallys until recently which certainly have high bar pressure but I've always liked the direct feel you get from kites without pulleys (which I first experienced with a pulley-less Cabrinha Contra).

I now have Ozone Enduro V2's which have no pulleys. They have light bar pressure and also a huge wind range and you can instantly feel exactly what the kite is doing without the slight delay and sometimes slightly spongy feeling that pulleyed kites can have. I suspect that Ozone are doing something clever with their bridle design.

I will never go back to pulleyed kites.

[plummet]

All ozone lei's are pullyless.

What do pullies give you?
Potentially more depowered and turning for less bar stroke.

Disadvantage can be more vague less direct feel, moving parts wear out faster than static bridles.

[alford]

The arguments for pulley less makes sense but why do big brands like North, who have the resources for the presumably extra R&D in developing a pulley less bridle, not do so? I guess what I'm saying is that I don't buy the argument that using pulleys makes the bridle design easier, cheaper and covers up for a lack of innovation.

[edt]

if you are a lazy kite designer pulleys can hide a variety of flaws in your design because they automatically even out all the stresses on a kite. When you get rid of pulleys there are no two ways around it, you will have stresses on the kite that are uneven and it's your job as a kite designer to work around these by changing the kite shape and bridle attachments so that overall the kite performs well. Pulleys don't make a kite better or worse, they don't change bar pressure or flight characteristics what they do is create an even load on the kite which means you can have a longer bar throw and more depower. Bridles have an immense down side. they create a saggy feeling to the kite and slower reponse. No way around it. The best feeling kites will have no pulleys and a short bridle, like for instance the old North Rebel, what a fantastic kite. When north went to a 4 line system, well they are relatively new to the this sort of kite, so they are still figuring it out. Ozone got on the 4 line kites right away and have had the no pulley system all figured out. As your figure stuff out, and iron out the details of a specific kite you tend to remove pulleys, as your design gets better and better. It takes a few years though, figuring this out is not instant. Cabrinha by the way loves to entirely change their bars, their kites, bring out entirely new models every year, so they don't have time to really perfect kites and that means you want to use pulleys because the designs are always different and new. The best kites in my opinion are those that are pretty much unchanged for at least 3 or 4 years, that gives the manufacturers time to slowly tweak the kite until it's perfect. When you are constantly changing your line up so it's "New and Improved!" that a recipe for a soggy feeling kite because you add a bunch of complexity into the bridle to make up for a rushed kite design.

I just wish kite manufacturers didn't feel the need to constantly "improve" their kites, but I guess a customer won't buy a new kite if it's exactly the same as last year.

[Bruce Buffer]

https://youtu.be/Kh_SUh1xUZY

[dwarf]

I currently have both Ozone (no pulleys) and OR (pulleys) in my quiver. Over the years I have flown tons of kites with pulleys. In my experience there is no difference in direct feel. Also never in 10+ years did i experience pulley failure on my bridled kites.

Most crap spongy kites I have come accross over the years had long bridles or front & back bridle connected like the early cabs.

[jespin4845]

I’ve tried a shit ton of kites, my favorite drifting kites have pulleys, usually faster turning kites have had pulleys

I love a good pulley-less Kite, but for me kites with pulleys do it better

Sure every once in a while I have to rinse them out in a cup of water and add silicone spray...oh well

When I was a beginner I had to wash the pulleys every session cause I was constantly getting kites wet and then going back to the sand they would get stuck with sand in them

Now I rarely get them wet so it’s once in a lie moon I wash the pulley out and lubricate it

[jespin4845]

I agree with dwarf, spongy kites are the ones whose bridle can wrap on its tip or longer bridle, generally a kite that is spongy now a days is just a beginner Kite to an advanced rider