Vorsprung Luftkappe – Fox Float 34, 36 and 38 S4 Suspension

“I just wanted to follow up and let you know the Luftkappe and Fractive tune on the fork are incredible.  I have 3 rides on it now and have the settings almost all dialed.  Things I’m noticing so far:

1. The fork smooths out the small chatter making it much easier on my hands and wrists
2. large hits are very controlled and it has a much more bottomless feel
3. the control it gives me going through chunky corners is scary good.  I’ve always liked the feel of the rear suspension on the bike, but it can’t keep up to the fork now in these situations.

I’m a very happy customer!  Thanks for the awesome service.”
Steven Wiebe

What’s included in the kit:

34 Evol: Upgrade low friction air piston assembly.
34 NA2: Upgrade low friction air piston assembly & upgrade low friction, low profile sealhead
36 Evol: Upgrade low friction air piston assembly. 
36 NA: Upgrade low friction air piston assembly & upgrade topout spacer ring

Note: If your 36 Evol tops out noticeably, you will need to replace your air shaft assembly before purchasing the Luftkappe. Fox have updated this part due to the topout issues that many of the 2018 36 Evol forks had. 34 forks do not have this issue.

Relevant Fox part numbers for the new air shaft assemblies, by travel:
180mm: 820-02-534-KIT
170mm: 820-02-535-KIT
160mm: 820-02-536-KIT
150mm: 820-02-537-KIT
140mm: 820-02-538-KIT
100mm (36 831): 820-02-539-KIT

If your fork does not have noticeable top-out issues, you don’t need to replace the shaft before installing the Luftkappe.

INSTALLATION INSTRUCTIONS & VIDEO

FAQ:

1. Can I install it myself?
Yes, provided you have access to the supplies and tools listed in the installation instructions above. If you’re really crafty (and EXTREMELY careful) it is possible to install the Luftkappes (all Evol variants) without the installation tools, however the risk of damaging things is much higher and we really don’t recommend trying. If you choose to take this route and damage your air shaft (or anything else), we cannot be held responsible – we make the tools available for a reason. It is not possible to install the 34 NA2 Luftkappe kit without 10mm shaft clamps and the bullet tool – you’ll damage the shaft AND damage the seals on the new sealhead.

2. Does it work with TALAS forks?
No, sorry.

3. Does it work with versions of the 36 prior to 2015?
No, sorry!

4. Does it work with 32s or 40s?
No, sorry.

5. How does it actually work?
It enlarges the negative air chamber to reduce the initial spring rate. This lets you run higher air pressure for more support in the middle and end of the stroke with improved sensitivity in the start of the stroke.

6. Is it compatible with MRP’s Ramp Control cartridge?
Generally speaking no. If you are running your fork at least 30mm shorter than its maximum available travel, then yes.

7. Shouldn’t I just buy a new fork instead?
Sure, they’re about the same price as the Luftkappe.

8. What parts does it actually replace in the air spring?
It replaces the plastic piston itself, and the rubber topout bumper in the 34s is removed but not replaced (36 topout assembly is unchanged). You reuse your air shaft, though the 34NA2 kit comes with a replacement low friction, low profile sealhead comparable in size to the stock 2018 Evol sealhead. This is also why the NA2 kit is more expensive than the other two – it’s basically a 2018 Factory update on top of a Luftkappe.

9. Who is this NOT suited for?
The Luftkappe is outright superior to the stock air spring for nearly everyone, however there are a few cases where it might not be for you:
– If you run your 36 at 180mm, it will be quite progressive. You may like it, but you may also find it hard to use the last 5-10mm of travel – if this would bother you then have a think about it first. At 170mm and below it will  be fine.
– If you like running really low sag for some reason. The Luftkappe runs more sag than the stock fork, but is firmer in the mid stroke – similar to a coil fork, but with ending-stroke ramp up to prevent harsh bottoming. If you’re the kind of person who wants the fork to run 5% sag, this isn’t for you. We could point out that a setup like that probably just means your handlebars are set too low and you’re compensating with oversprung suspension, but we aren’t here to judge you, so maybe just don’t buy it.
– If you’re anal about your fork having an exact (but rounded-to-the-nearest-10mm) amount of travel. Because the Luftkappe balances forces at a pneumatic topout, the force right around topout is very low (literally zero other than friction), meaning the weight of the bike alone will cause it to sag a few millimetres. Your car’s suspension sags under the vehicle’s own weight, so should your bike – unless it was so sticky, overly stiff or over-preloaded that 10kg of bike weight wasn’t enough to cause your suspension to move at all, of course. If only having an apparent 148mm out of a 150mm fork is a big deal for you, stick with the stock fork. 

(in)Compatibility Information:

Luftkappe IS available for:
34 Float NA2 (Performance, Performance Elite and Factory Series, 2016-17), 130mm and higher travel
34 Float NA2 Evol (Performance, Performance Elite and Factory Series, 2018+)
36 Float NA2 Evol (Performance, Performance Elite and Factory Series, 2018+)
36 Float NA1 (NA)

Not compatible with:
Rhythm-series forks
E-bike specific forks
Non-Evol (pre-2018) 36 forks
34mm forks for 29″ wheels with 150mm or more travel
Pre-2016 34 forks
Pre-2016 34 forks that were later updated with the factory NA air system update
Any TALAS forks
Any 32mm forks
Any 40mm forks

Not sure which year or model your fork is? Grab the 4-digit code off the back of the fork lowers and check it here – FOX 4-DIGIT CODE CHECK