There are a number of aftermarket suspension tuning outfits looking to eke out whatever performance they can from a suspension product. From those developing alternative methods of affecting the end stroke, to completely new cartridges and internals, the options are pretty good. Vorsprung Suspension is one of the more recent of these outfits and their Luftkappe, released late last year, is the latest product from this team out of Whistler.
The Luftkappe is a machined tube that replaces the piston in the air spring of a RockShox Lyrik, Pike or Yari fork. It increases the negative air spring, which aims to make the fork lighter off the top, while the increased pressure used (a starting point of about 10% more than the typical pressures used in a stock Lyrik/Pike) allows for increased support in the mid and end stroke. It can be used with RockShox's Bottomless Tokens, though there are some limitations to consider, depending on the fork model that the Luftkappe is going to be used in.
Luftkappe Details • Larger negative air chamber
• Improved mid-stroke support
• Compatible with Tokens in some models
• Optional 10mm shaft clamps available for self-install
• Weight: 30g (~21g more than stock piston)
• MSRP: $85 CAD (Luftkappe only)
• MSRP: $235 CAD (Factory Service and Luftkappe install)
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vorsprungsuspension.com Vorsprung makes the Luftkappe in-house, in their own CNC lathe with live tooling machine. This was the first product that the team fully developed in-house: design, prototyping, testing, and production. The Luftkappe replaces the piston in the air spring side and can be done at home, by those that are comfortable with working on their suspension, or you can send your fork to the team in Whistler, where they can install it for you, which includes a service as part of the process and carries an MSRP of $235 CAD.
For those that may be interested in trying the Luftkappe and already have something like
MRP's Ramp Control Cartridge the good news is you can use both, but there are limitations. The two can only be used together in a Pike that is up to 140mm of travel, and a Lyrik up to 160mm. Going beyond these there is not enough room for all the pieces as the fork compresses to full travel. It also doesn’t work with the Dual Piston Air fork models.
Installation of the Luftkappe requires the fork be torn down and the stock piston removed. Actually removing your piston can be a bit of a tricky process, so if you're not comfortable with that, it might be best to send your fork in to Vorsprung and have their team take care of it for you.
Once the stock piston is apart, the Luftkappe, which contains a number of key parts, can be split up and installed. Some grease and careful management of the new o-rings is required, but it's a fairly straightforward process for the mechanically inclined.
Performance Let’s not kid ourselves; the Pike and new Lyrik are both exceptional forks out of the box. The chassis is sturdy and reliable, and tuning the air spring is very straightforward—they’re also easy to get set up to a point that's great on the trail. That’s not to say that the stock range of tuning options works for everyone, but they’re damn good from the get go.
After some time on the Lyrik, I found I wanted more support through the mid-stroke of my 170mm Lyrik and for the end stroke to be more consistent with the rest of the travel. Dynamic ride height wasn’t quite where I wanted it to be, despite what I did while trying to keep the performance off the top that the Pike and Lyrik are renowned for.
To get close to what was my personal, ideal suspension tune, I had previously arrived at three tokens, about 70psi—roughly 15psi more than recommended for my weight. But I still wanted more from the fork. It would use a lot of its travel before hitting a "wall" deeper in the stroke, where the tokens became more apparent. Removing tokens and adding more pressure got the mid-stroke closer to where I wanted, but the top end suffered. Nothing further from the externally adjustable LSC was helping either.
Naturally, when first hearing about the Luftkappe and what it claimed to do, I was intrigued. Rather than working on the effects of the air spring at the end of the stroke, Vorsprung claims that it would make the fork lighter off the top (feel more “like a coil”) and allow for more support through the mid. Sounds good, right?
Steve and I initially set the fork up with 10psi (12%) more air. Given my complaints of the wall at the end of the stroke (and my fork being a 170mm travel version), we removed the tokens altogether. As a general starting point, Steve recommended running 1–2 clicks more rebound too. I quickly arrived (one to two rides) at my happy place of 8psi more than pre-Luftkappe, while the rebound now sits at between the one to two clicks difference mentioned, depending on the riding.
The Luftkappe's change to the feel of the Lyrik was immediately noticeable on the trail. Traction was increased across chatter and the fork remained higher in its travel and more stable, improving the dynamic ride height without sacrificing the top end. My confidence soared when hitting sections with a lot of chatter and mid to large-sized hits, and the result meant more comfort and speed through such sections.
Flat corners with chatter throughout were another area that the performance was easily noticed, with more confidence in the fork's ability to support me and the actions made throughout. My fork remained on line more easily than pre-Luftkappe and made up for more hack moves. The Lyrik went from being a really, really good fork to a great one, with more efficient use of the stroke and more traction. It was always there to get me out of ugly situations and I have far less of an issue with finding myself too far through the travel in heavy situations—it's saved my arse on a number of occasions and while it may have been possible to get through without it, less rider input was necessary to do so. Never did the fork do anything quirky or out of sorts.
Pinkbike’s Take:  | The Luftkappe may not be for everyone, but for those looking to squeeze out some extra performance from their Rockshox Pike or Lyrik it’s definitely a worthy investment. The added traction together with increased support really allowed for reckless abandon, knowing that the front of the bike was going to stay on track and keep on trucking, keeping me out of trouble.
If you're not quite comfortable performing the upgrade yourself, you can even send the fork to Vorsprung where they will install the Luftkappe and send your fork back to you, ready to roll with some fresh juice to boot.—AJ Barlas |
Lyriks and Yaris have larger negative spring chambers than Pikes and would only benefit from 160mm stroke and above.
This Luftkappe sounds dope.
-- Steve
To clear up some potential confusion here - the way the air springs are constructed in these forks, the air piston always starts at the same distance from the bottom of the stanchion. Different travel configurations just have more shaft or less shaft sticking out the bottom. What that means is that a longer travel variant has the piston move further in to the fork at full compression, meaning a higher compression ratio. Likewise, with longer travel Yaris, there is more air in the lowers to begin with, hence a higher compression ratio there too (same with the Lyrik/Pike, but they only have the bottom of the air side stanchion sealed, not the damper side like the Yari does).
As a result, our standard recommendation when considering a Luftkappe is that the Lyriks work really well at anything up to 170mm (as tested in this review) and are quite progressive (maybe too much for some people) at 180mm, while the Yari at 180mm is really progressive (probably more progressive than most people are going to want), at 170mm is still fairly progressive (ok for some, a bit much for some), and at 160mm or less is great pretty much across the board. As a general rule, if you've played around with your stock setup and come to the conclusion that 2 or more tokens are necessary for your preferred setup, it'll work very well for you. If you're running 1 or none because otherwise you find it's too progressive, you may not like the feel as you won't have the room to remove sufficient tokens with the Luftkappe.
I too have a Yari with 150 mm of travel and run it with one spacer and no Luftkappe. I ditched the MoCo and replaced it with a Splug. With the MoCo I had to live with the compromise of having too little LSC and too much HSC... now with the Splug it is perfect!
If I understand the problem correctly, you are saying that pressure in both lowers rises when the fork is compressed, and since the damper side is sealed at the stanchion, the volume in the damper side lower gets rather small under compression, so the force rather large.
IIRC there is a plug held in the damper side stanchion by a snap ring. Further, IIRC, that plug is just a hard resin or plastic.
I realize this is a long shot, but could I just drill a hole in that plug or is it sealing damper oil?
Thats pretty genius....
I'm ill and finding out myself seems like way too much effort right now
I'm running about 10 psi more than before with no tokens anymore. The fork is more supple at the top, better mid-stroke and still doesn't bottom out. I did find that pressure is more sensitive. I tried letting out just 5 psi more to test and the fork got really soft, where prior 5 psi made much less difference. Totally worth $100!
www.tftuned.com/luftkappe-upgraded-piston-kit-for-solo-air-pike-yari-lyrik/p3288
You're right, modification of the air spring rate calls for a matching modification of hydraulics, too, because both are designed to work together.
When I worked in France back in 2014, there was a small renowned boutique called Novyparts that allready did these things.
www.novyparts.com/optimisation-novyparts-suspensions-vtt/rock-shox-fourches/optimisation-specifique-pike-et-boxxer.html
They did a great job working on the air piston AND matching hydraulic piston mods in the charger damper, plus a custom shimstack setting (based on weight, practice, etc...) for 170 USD/Euros.
I'm not a racer, much closer to a weekend warrior but it was amazing how a custom work changed the pike behavior, even for my skills level.
had to soak in boiled water for 5 mins to remove the shaft head
Then clamped shaft in my workstation with eBay golf club clamp (3 quid) and it came off with a bit of effort
www.ebay.co.uk/itm/Rubber-Vice-Clamp-Protect-your-Golf-Club-Shafts-Steel-or-Graphite-/121745718338?hash=item1c589c3c42:g:osUAAOxyyUtSbM4D
or am I barking up the wrong tree? :/
@dingus - I want for one for Lyrik.
The flip side of the larger negative is the smaller positive. I went from 2 tokens pre-Luft to 0 tokens post-Luft. I don't recall the specific pressure I had settled on but I had set it so on trail I was still using full travel occasionally for the biggest drops I encounter. The downside was that I ended up with a sag ride height that was lower than I preferred.
I have no idea what you are referring to regarding trail or open modes. I said nothing about that. I ride my fork in open mode all the time.
Set sag to be ~15% (so its closer to 25% when going downhill) and see how it works...
I could point you to Steve's own numbers and show you graphically but like I said in my initial post, I knew I'd be in the minority here as the product does as advertised. It's just not for everyone unless 1) you want a spring curve more progressive than stock with 2 tokens or 2) don't mind a lower ride height or 3) don't mind less travel.
This is why its so important you run *less* sag and higher PSI. Theory is the negative spring makes it more supple "off the top" while riding higher in its travel (remember, more PSI) giving you more usable travel, more mid stroke support (remember higher psi) while still being able to use your travel when you need to (more linear).
I think what you are finding is the Lyrik is too progressive regardless of Luft or not.
Fork was set up as per instructions.
How many mm is your Pike? Assuming 150mm+? It sounds like you need to run your Pike with 1 token so that you get your 15% sag on flat ground and can still bottom it occasionally. So, yea, you are at the end of the spectrum where the progressivity of the Luff, while fairly minimal, is too much--IF you're bent on using full travel on big hits.
Are you lightweight, and/or don't ride hard/steep terrain? Wondering because I weigh 145lbs and run a 130mm Pike with 4 tokens and 69.5psi. I get basically 5% sag when riding flat and bottom a few times a ride, on big hits when on steep stuff. (we have a lot of really steep stuff we ride so lots of weight on front wheel) ... I'm looking at the Luff so that I can get some sag back when riding flat but still have mid-stroke and bottom out resistance.
You said- " I don't recall the specific pressure I had settled on but I had set it so on trail I was still using full travel occasionally "
Bad set up or bad english, i have no idea.
The solution ended up being riding faster
I'm more Richie Rude sized, so I went from 3 tokens 95psi to 1 token and between 100 and 110psi depending on what we're riding.
Love it. It makes the tire feel like play doh smushing and conforming perfectly over the rocks.
So MTB companies just cater to the tastes of their clients. Not opinionated sour pricks who know everything. I personally could not give a flying sht if they gave me a Pike without Luftkappe, DVO Diamond or Fox 36 with 20mm axle. The only fork I can be excited about is Öhlins RXF 36 coil. The rest is just... the rest.
No 350 NCR Ti?
Are you shitting me? I missed the part where it said it was only for 29ers I guess??? I was so excited for that fork
No doubt this product is excellent if that's what you want, but not everybody wants change so either buy it or don't, there's something for everybody.
1.make larger chambers
2.Start stuffing them with spacers
And yes I would call that a mistake. Mistakes are a normal part of product evolution. You could consider the geometry of every 1990's mountain bike a mistake. They were fun at the time but now we know that we can do it better. They could have done it better back then, too.
Killer product!!
For lighter riders, I agree that reworking the damping is going to have a bigger impact, but I have yet to encounter anybody who had done both and isn't incredibly pleased.
That said, people end up with RS suspension on their new complete bike because SRAM is just a big OEM player (though Hayes could have been quite big too) so for people not happy with their new Yari, Lyric or Pike the Luftkappe is a great solution.
The elephant in the room is that every time Vorsprung comes up with a clever upgrade, the original manufacturer can just benchmark it, and build that performance into the next generation of products. (See Corset>>EVol, and now Luftkappe >> Debonair Forks).
I think it's a net benefit to the industry, because the big manufacturers don't have to push performance into an unknown frontier, they just have to figure out how to mass produce something that can keep up with a bespoke tuned version of previous generation products.
Hate to rain on the parade, but haven't SRAM made a similar Luftkappe upgrade to their new model forks?
Currently running 3 tokens, which is good for mellow stuff around here although not brilliant small bump compliance. If I ride anything steeper I usually put an extra 5-10psi in the fork to stop travel vanishing and potentially throwing me over the bars.
So the luftkappe will help the fork stay in the mid travel for longer and hopefully stop the feeling I'm going OTB, or should I just run 4 tokens?
Few days ago i had a first ride with new setup and i saw that Lyrik sucked down 1-2cm of travel, to pull it fully (and hear bang) i need to use a lot of force, like 10kgf ? (my pressure - 60psi)
This evening i've pressurized it to 100psi, however nothing changed (still missing >1cm of travel),
removed bottom bolts a bit - keeping lowers, knocked them with rubber hammer to detach rods from lowers (in case there was negative pressure in lowers).
I've removed all the air cycled forked few times (extended it using force and compress), pressurized to 20psi, cycled, pressurized to 40psi, cycled, and finally presurrized to 60fps.
Looked good, measured stanchions - was about 170mm.
however two hours later (bike not used during that time), i've cycled it few times and i saw that i have only 160mm - fork sucked down 1-1.5cm of travel again.
Did you experience loosing travel ?
www.biketheworld.ch/collections/suspension-upgrades/products/vorsprung-luftkappe
@zombiejack33 if you let the air out of the fork very quickly, it is not able to equalise the positive and negative chambers fast enough and will suck a long way down because the negative chamber is still charged even when the positive chamber is empty. You need to extend the fork to equalise it in this case - either by adding a bit more air or forcibly extending it, or a combination of the two, then depressurise it slowly enough that it can equalise as it depressurises.
Hope this helps.
1. First up, it's obviously heavier. Some people care, some people don't, either way that's cool. It wouldn't bother me personally.
2. As a conversion kit, it's inevitably going to be significantly more expensive. We wanted maximum performance per dollar spent, and at $85CAD I think that's hard to argue with.
3. It'd score the inside of the stanchions, if it isn't fully contained within its own cartridge (which in turn adds both weight and cost over a typical spring-in-the-stanchion setup). That's ok if you're certain you don't want reversibility, but otherwise it's expensive damage.
4. You're stuck with the existing spring rates provided by the manufacturer.
5. Coil springs in short travel forks need a good anti-bottoming mechanism (either hydraulic or pneumatic), otherwise you end up running an overly stiff spring rate or a ton of compression damping to resist hard bottoming. Even in DH bikes I feel they're hugely beneficial, and you have way more energy absorption with that much travel. Air springs give you a lot of tunability there.
6. Travel adjustments are either more difficult/complex, or more expensive - even if you just changed spring plunger length you run into issues with needing to adjust the spring rate simultaneously, which means purchasing another spring.
Horses for courses though - coil forks generally feel rad, but nothing is perfect.