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Guide to the Airush Union 4 - real world what's new, where it's gone, what it's like..

Posted: Tue Sep 11, 2018 5:00 pm
by MikeBirt
Hi All,

Over here in the UK we have a good following on the Union series kites - so I thought it prudent to get this on the web as reference for anyone who's wanting answers when looking at the new Union 4. Airush do dance about with this kite between years and 2019 is no exception. So for all those Union riders of past seasons, and those potentially looking at it for this season I've put together a guide beyond what the brochure says. Apologies if it's a bit tech heavy later on, but you have to understand what it is to understand how it feels in comparison to previous years. It's an explanation of pros and cons, I'd like to think critically balanced, with reference to it's predecessors.


I'll start with a fluffy summary -
- All change for the Union series of kites, with new shape, bridle and feel.
- Focussed higher wind / energy multidiscipline boosting / freestyle kite
- More focussed than any Union So far, but ironically easier and less technical to use - closer to the C Kite in handling than ever (with of course more sheeting ability than a C).
- No more pulleys, so more feedback, and more dialled in nature if slightly smaller sweet spot
- As big a physical wind range as years gone.
- Loves corners, looping at higher power levels.
- Well suited to freestyle / park work.
- Build quality is (arguably from some peoples viewpoint) the best in the industry - CERTAINLY the most expensive to build in the industry.


Now the more detailed (and sorry quite technical in places) stuff -

The Union comes from a lineage that started with the first three strut high performance kite being the 2014 VX. Since then we’ve had the 2015 Vx, Union 1, Union II and the most recent Union III. For those of you who know the Arirush range, this was the premium expert Airush kite that sat under the Purist C kite - the Razor - as the high performance but multidiscipline real world solution to the widest possible audience of expert riders. Though as the seasons change, and with them the demands of its riding demographic (freestyle / woo / wave mix) this model of kite has changed with it. If you look at the Lithium, Wave, or Razor in the airush range, you’ll see a gradual progression of kite through the years, but the Union and it’s forbears have occasionally been very different year on year.

This year sees another completely new kite - in spec and feel, so, having a few sessions on it now we think it’s best to give you a real world lowdown on the new girl, so you know what’s what.

This years biggest news is that the pulley bridle is gone. Not since the days of the Vapor have airush used a pulley free bridle in the flagship mainstream kite, though they do supply the 2019 Wave V8 with it as an option this year. Now everyone has their views on pulleys, and to be honest every opinion valid, as every experience is equally valid - so I best just stick to the case in hand - this new kite.

The airush pulley bridle has been a constant companion for many years and it offers one big advantage - constant steering input from full power to full depower, so essentially the kite balances itself on front and back lines so your rear lines have weight and steering input even when the kite is de-powered. It’s a feel that Airush riders have grown with for many years, and compared to many bridled pullies in the world, the Airush one is very, very direct. Not perfect, but pretty good (there is no shortage of terrible bridles in the industry).

That said the lack of it on the Union 4 is most definitely noticeable. The pullies do soak up some bar pressure between full power and full de-power so without them the Union 4 has more feel between extremes of sheeting angle. You need to sheet the kite in to turn with any speed though and it also brings a very different bar loading - sheet out - the bar pressure is light, sheet in and it’s heavy. Pulleys are like power steering - they graduate the sheeting pressure so you don't really feel much contrast between light and heavy loadings, which makes you less aware of how much turn you are initiating.

So what does that mean in terms of performance? - well, not much in terms of what it lets the kite physically do - it’s a feel thing. One thing is clear though, if you want the Union 4 to move fast you have to be deliberate, full sheet, full power and the more beans you give it the faster it reacts. It’s quite a physical kite in that respect. If you are cautious with it then it’s cautious with you, and there is something very reassuring in this. If things are getting out of hand, it’s hard to do the wrong thing by light accidental input - crashes are mild. The kite is essentially in safe mode when sheeted out - so it has a failsafe feel about it.. Bar pressure is higher than ever when fully sheeted in, but lower than ever when sheeted out. At cruise - mid sheet - it’s the same as the Union III, slightly less than the Union II.

Add this up and you get a much more tactile riding experience. I’ll mention this later - but for anyone who has ever had time on the Razor will attest - it’s a kite that gives you more information - angle, position, power and speed - than a pulley kite. It’s an advantage in feel but also security, for all the big slams that left me with injuries had pulleys involved - granted I ride pullies more than not, but I find it very difficult to get that out of shape with a non pulley kite like a Razor.

Next is range - Any experienced rider will know that every kite size has a sweet spot. You can ride the thing outside of this, but it’s handling and efficiency is compromised. The pulley free kite may have more intuitive handling, but that handling sits inside a smaller sweet spot. The pulleys give you better turning ability when sheeted out - either carving or generally overpowered, so they do extend that sweet spot. That said when you are using this extended sweet spot it’s a fudge - your kite is running at a sheeting angle that is not optimum. it’s drag is greater than it should be, and if you want more efficiency and crisper handling you need the next size down, but that means more sizes in a range to fully extract the best from every session.

Next is back-stall and the usable physical windrange. Outside of the sweet spot is the ultimate bottom and top end. We call the maximum amount of back line tension before the kite stalls on any kite the stall point. As you continue to sheet in - more power - more power - then stall (less power) then flies backwards. Now this stall point shifts around according to windspeed, and some kites are a lot more sensitive than others, you’ll all have experienced this - mostly in light winds when kites stall and start flying backwards. The position of the rear pigtail knot will determine how much and how little tension you can get on the back lines…
As far as sensitivity to stalling goes, the original 2014 VX and Union III were sensitive - the Union I and II were pretty tolerant, meaning you could over-sheet them and get more power and speed of turn out of them in the lightest of winds.

Happily the Union 4 is the most tolerant of all. It's stall resistance is hilariously high, so you can get away with murderously poor setups to get the kite back in the window and develop grunt if needed. That said the stock setting is perfect for conditions that match the kite’s sweet spot, but if you need to, you can get a lot more power from it by putting knots in the line closer to the kite. It’s an imperfect solution, but when fudged like this the Union 4 has as good, if not better bottom end than the union II, which was the most grunty of them all.

Airush is a riders company. They make the best kit they can, and ship it with the most dynamic settings they can for each size in it’s optimum conditions - straight out of the team riders hands. That said the real world is not optimum, and years of feedback (back to the Vapor I) have had designers, riders and public arguing about what works for them. Thankfully the Union 4 is extremely tolerant to a number of different setups, so don't be afraid to shorten your back lines if you feel you need more low speed power, just be aware that the stock settings, ridden fast and free, once the optimum wind range is reached, is the optimum set of this size according to those who built it…

As to the top end, it’s possible that the pulleys will further increase the sheet angle, but by the time you get sheeted to this point, and your rail grip is failing, you should have been in for a smaller kite 10 knots ago, and for the record the frame is absolutely rock solid, even when it’s crazy gusty and cold, so the top end is more than you ever need, certainly should ever need..

If that’s all the tech and boring stuff out of the way - what does it feel like? what is it good at?

For me, higher energy riding, looping and really pushing the boat out with your powered riding. It reminds me more of the Razor than any other mainstream kite that Airush have made. More focussed than the Vapor’s were back in the day, but similar rider demographic - solidity and calm in nature when you are off the throttle and extremely capable and deliberate when you are on it.

It goads you into pushing the boat out more and more, even if it’s quite a physical riding style. Unlike the Razor it’s far more sheet-able, so you can come of your rail and rest, you can turn it off when you need to, and run at lower general riding energy levels when you are cruising.

Around the corners it’s not quite as powerful as the Razor, but not far off, which is high praise. It’s more intuitive than the Union III, which in turn was much more capable under power than any of it’s forbears. For those who like to loop it’s a blast. Pretty sure my kite was sick of going around corners by the time I came in yesterday. It goads you into loading harder and throwing turns earlier. I have no doubt that it is a perfect kite for building your confidence and improving your harder core more powered ability over multiple sessions.

Boost wise, talking Woo numbers, it’s up there, more so when you are powered. It’s not pulling the numbers that the Vantage can, but it’s ahead of the Razor or any of the other kites in the Airush range. As to the industry - it’s hard to tell without more comparative testing, but if this is of concern, just buy a 9m Vantage. That will get the job done for you - it’s a total woo cheat (but with compromise) - the dark horse of the Airush range I assure you. The Union 4 likes to be at full power to really rip you up, deliberately sheeted in and steered to direct it up on takeoff, like a Razor, to get it where it needs to be for maximum rip off the water. Coming down is so much fun though - it loves to be thrown around. The trusting feel it gives pushed up the jump heights into power levels that you would otherwise think dicey, feels a lot more trusting than the Union III did at these higher power levels, which is much more real world, as every rider appreciates a setup they trust and gel with.

How hardcore is it? That depends on how your definition. It’s easy, really easy to ride about with. It may not have the range of the lithium, and may like a generally higher cruising speed, the same as the union III, but it’s easy. It comes alive when you start getting aggressive though, intuitively so, and you don't really need to be an expert to start poking at it - it’s very calm. It’s more physical than the Union III certainly, and more focussed in sweet spot but certainly more accessible and relevant to most riders, right up to the head rider’s standard - Sam Medysky - and he’s pretty damn handy, so that is a good endorsement for it’s ability, beyond it’s fail safe feel.

Somehow I think that in contrast to years previous, Sam and his counterparts will elect to spend the majority of their time on this kite and not the razor, which when you factor in that it’s quite an easy non threatening bit of kit, makes it sound like a good bet.


So that’s about it.
Worthy of note is that the bag is much bigger this year with a central mesh panel and board carrying straps. best bag yet I think, certainly the most practical.
Load frame is genius - no splits, no stretch - why Airush are the only ones doing this, - cost - it’s expensive to do, and while everyone else bangs on about canopy cloth quality - Airush use the same upper end cloth but with this engineering workaround that bypasses this discussion completely.
Bar is the same configuration and geometry as we all know, - I like it a lot, and never alter the size throughout the size range.
Relaunch I have not covered, in the conditions it’s meant for not really worthy of comment as you’d not be looking at a kite like this if relaunch was mentioned (it's actually pretty easy for it's type).

Hope that helps people looking at this kite - from someone who follows and appreciates the brand and it's work so far, I hope it's a success, it's got a much wider appeal this year I think.

Promo Video -
International web page -

Re: Guide to the Airush Union 4 - real world what's new, where it's gone, what it's like..

Posted: Thu Sep 13, 2018 1:26 am
by alexeyga
With all due respect - that's one huge pile of bullocks typed up by somebody who definitely is better at composing marketing speeches - than at riding. Did they torture you into publishing it or something? I mean - it's bad enough that you can't take a piss nowadays without stumbling over yet another piece of promotional crap from multi-colored kiteboarding - but now it appears that Airush is also forcing something down our throats?

Re: Guide to the Airush Union 4 - real world what's new, where it's gone, what it's like..

Posted: Thu Sep 13, 2018 7:04 pm
by MikeBirt
Sorry for you sir.

Re: Guide to the Airush Union 4 - real world what's new, where it's gone, what it's like..

Posted: Wed Oct 03, 2018 10:32 am
by MikeBirt
A separate review.
John Bouchet - Jersey - UK
This guy is well ahead of me in standard (freestyle) and also foils and waverides, so pretty allround..
He uses Razor mostly with a bit of Ultra and Wave.
I had a mega first session on the Union V4 10m yesterday, I stuck my woo in freestyle mode and was able to get comparable results as my 11m Razor, landed most of my decent unhooked tricks, 313, front 2 blind, blind judges etc and they felt great. I was most impressed about that you could do respectable unhooked Kiteloop 313's on it, the only other non C kite I've ever been able to do that on was the slingshot RPM.

Less hard spankings, love the direct feel, kites quite slow in standard setup which I liked. The best union yet for my style of riding by a long shot.

It's nice I can use the same bar as my waves as most of the time I have a strapless session then either a boosting or Freestyle session afterwards and now I only need to change the kite which saves loads of time and less luggage to carry on trips!

The kite boosted really well and the transitions were great giving it a little extra time than the razor.

Compared to the razor the razor has more line slack and the kite loops are harder edged than the V4. The Union seems to have 90% of what the razor can do and transition into other styles of riding much better.

Re: Guide to the Airush Union 4 - real world what's new, where it's gone, what it's like..

Posted: Wed Oct 03, 2018 10:48 am
by MikeBirt
Another review...

A lot of the same themes in everyone else's review coming up.
Kites Tested
12m and 9m in winds ranging from 10 knots to 25 knots

Three Line Summary
High Performance Allrounder

Out of the Bag
The Union4, as its name suggests is the fourth incarnation of Airush's high performance kite for intermediate-advanced riders.
Like the majority of the Airush range, it benefits from their load frame technology in addition to Technoforce D2 rip-stop - creating lightweight strength, durability and high performance.

There are a choice of bars on offer - The core bar with either strap or cleat de-power system, progression bar, access bar for small riders, or the uncluttered Ultra-specific bar, with large de-power throw rather than a trim system. All bars come with low diameter tubing and a comfortable, hard-wearing grip; Brain quick release flagging the kite onto a single front line, heavy duty flying lines and integrated bar ends.
The kite comes in a surprisingly small bag, as it packs down to a space which I'd say most 9's would struggle to fit in. Making it a great kite for travel or simply just chucking over your shoulder with your other kit when you're not sure what the winds gonna do.

In the Air
Now before we go any further, I must mention the default knot on the rear line pigtail; If you fly the kite with this setting it feels incredible in the way it flies, pushing well forward in the window and giving great upwind performance with medium-light bar pressure, but does suffer from a lack of low end grunt.
I opted to fly it with the rear lines connected a few inches further up the pigtail, and with this setup you get all the benefits of the lower connection setting when sheeting out, but with far improved power, low end and medium bar pressure when sheeted in. The rest of the review follows with the kite in this setting.

The Union feels super refined in flight and generates a great deal of power when you move it through the window. The pulley-free bridle gives a nice direct feel, and bar pressure is medium on the middle setting, but can be altered to suit user preference.
Turning is fast even on the 12m, provided you're assertive with the bar, on the 9m the Union whips around quickly generating a good surge of power.

On the water
The union has a very wide wind range - plenty of grunt at the low end, and power can be dumped away by sheeting the bar out, so I'd expect an excellent top end; I took the 12 out in some pretty serious winds, and felt nowhere near the upper end of the kite - making it a great choice for variable/gusty conditions.
The union generates considerable extra power on tap when whipped around the window, making it a lovely kite to freeride aggressively - blasting in and out of turns, boosting, loops and underturns.
The upwind ability of the Union is very good, more so with the bar pushed out a bit. The relaunch is good for a kite of this style - better than the razor, yet not quite as good as kites with more sweep down to the wingtips.

The power high depower, and power on tap also makes it a great kite for boosting, and I was very impressed with the height and hangtime I could get on even the 12m without it being crazy powered. Its fast turning response and power in the turns also makes it an awesome kite to heli-loop; the video below shows me doing a double heli on a 12m, which is impressive indeed. For kitelooping, the natural boostiness gives you a good height cushion before pulling on your backhand, and the kite whips around quick giving plenty of time for landing. With the bar pushed out a bit the kite does a wider forward turn with a smooth powerful pull, which is great to set the heart beating.

It's also a great choice for freestyle - the direct feel gives a great connection to the kite and you can gain power and height by redirecting the kite to suit your needs. It unhooks very well with decent amounts of slack, and is a great accessible choice for someone wanting to progress without many of the downsides of a more hardcore C shape.

The Union is a great choice for an intermediate/advanced rider that want's more from their current kite; whether that be boosting big, sending some loops, working on wakestyle manouevers, shredding the water hard on a twintip, or use with a foil or surfboard. It provides a wider wind-range and better depower than the hardcore Razor, whilst still retaining many of its desirable features for wakestyle, and significantly surpassing it for boosting big and general user-friendliness and 4-line setup.
For me, the one thing i'll take away from my time using the Union is how much of a fun all-round kite it is - I love the variety of razzing around, boosting big, looping, doing freestyle and wakestyle all in one high performance package.

Re: Guide to the Airush Union 4 - real world what's new, where it's gone, what it's like..

Posted: Wed Oct 03, 2018 12:25 pm
by nothing2seehere
I don't suppose the bridles are MUCH shorter this year? Whilst I like the steering feel in the older unions, the length of the bridle makes setting up and packing up in strong winds a little more time consuming.

Re: Guide to the Airush Union 4 - real world what's new, where it's gone, what it's like..

Posted: Wed Oct 03, 2018 4:24 pm
by MikeBirt
nothing2seehere wrote:
Wed Oct 03, 2018 12:25 pm
I don't suppose the bridles are MUCH shorter this year? Whilst I like the steering feel in the older unions, the length of the bridle makes setting up and packing up in strong winds a little more time consuming.
Indeed - the new bridle is shorter, lighter, and more compact. I'd have to measure one to be sure, but rear line bridle (extension from kite end to pigtail) is a lot shorter.
Also - notably, the front bridles are more pulled out to the corners of the kite, which may also (from my kite testing days) be another reason why the kite feels sharper.

Re: Guide to the Airush Union 4 - real world what's new, where it's gone, what it's like..

Posted: Thu Jun 27, 2019 11:14 am
by qsilver_za
Hi I bought some unions do you have a picture of where the knot should sit from your testing and the other tester mentioned here? It feels very relaxed compared to my torches more like a naish pivot, could also be that the wind was 16 knots gusting to 20, was expecting a lot more pull in the loops.