Luftkappe Installation & Setup
For Fox 34 and 36 Luftkappe Installation instructions, click HERE.
Rockshox Pike/Lyrik/Yari Instructions
The Luftkappe can be installed by anyone who already possesses the tools and the know-how to service their own fork - or by anybody who has the tools and can follow instructions closely. Written instructions and an installation video are included below.
Key things to note before you start:
1. You need a torque wrench. Don't try it without one. Beg, borrow, rent, buy or steal one from a friend.
2. You will need 10mm shaft clamps to hold the air spring shaft. Please don't try grabbing the shaft in a vice or in V-blocks, you WILL damage it.
3. We refer to the Rockshox service manuals for all aspects of the servicing OTHER than the specific installation of the Luftkappe to the Solo Air shaft.
4. The Luftkappe is ONLY compatible with Solo Air forks. It does not work with DPA forks. The only compatible forks are Pike, Lyrik and Yari - and only the current generation Pikes and Lyriks (those with black stanchions).
5. Record your air pressure and rebound settings before you start doing anything else.
6. Don't do it drunk. Even if you're Australian.
7. You will need some supplies as well as tools - Slick Honey grease, 20wt WPL ShockBoost oil or Rockshox 0W30 oil, red Loctite, isopropyl alcohol and clean, lint-free shop towels.
8. The Luftkappe only replaces the piston - not the entire air shaft. We will be removing the existing piston from the air shaft, and replacing it with the Luftkappe.
9. Do NOT replace the seal head outer o-ring with the one provided in the kit if you have the old style seal head. The difference between the two is shown below:
Read the Rockshox service manual that applies to your fork to get an idea of what you're going to need to do. Note the number of Bottomless Tokens you can run at a maximum. They are linked to below:
Pike Factory Service Manual
(Token configuration chart on Page 12 of Pike manual)
Lyrik/Yari Factory Service Manual
(Token configuration chart on Page 20 of Lyrik/Yari service manual)
Execute the service procedure as laid out by Rockshox's service manuals, up until you have removed the air spring plunger assembly (including seal head) from the bottom of the left stanchion.
This is the actual installation of the Luftkappe piston. This is covered in detail by the service video above. The steps are outlined here:
a) Remove seal head assembly, circular washer, wave washer and topout bumper from shaft. Clean shaft with isopropyl alcohol.
b) Clamp shaft in 10mm shaft clamps with 30-50mm of shaft sticking out above the clamp. Make sure to clamp it nice and firmly. You don't need to go nuts, but don't pussyfoot around either, we don't want it to slip.
c) Use a 4mm allen key to undo the silver piston bolt and remove the piston from the shaft.
d) Remove the o-ring from behind the threads of the piston bolt and discard.
e) Separate piston bolt from piston.
f) Separate Luftkappe dome from its piston (can be done by hand).
g) Install piston bolt through Luftkappe piston (from the threaded side of the piston).
h) Install replacement o-ring (smallest in kit) onto piston bolt where the old one was. Push it right up against the piston.
i) Place a drop of red Loctite on the end of the piston bolt threads. Thread into end of shaft only until snug.
j) Using a torque wrench with a 4mm hex fitting, tighten piston bolt to 50-55in.lbs (5.6-6.2 Nm).
k) Replace o-rings on outside and inside of seal head if desired. Note: only do this if you have the new style seal head as shown above.
The shaft seal inside the seal head uses the mid-sized o-ring in the kit, the o-ring on the outside uses the largest one. Do not remove or replace the wiper that is in the end of the seal head (or damage it!) - the shaft sealing o-ring sits behind that.
l) Install the thicker circular washer back over the shaft, followed by the wave washer, then the seal head assembly. Make sure the seal head assembly is oriented correctly. Note that we do NOT reinstall the topout bumper.
m) Remove the top cap and remove two bottomless tokens (if they are installed).
n) Reinstall the top cap.
Referring back to the Rockshox factory service manuals, lubricate the Luftkappe piston & its main seal very liberally with Slick Honey, then carefully install the air shaft assembly along with the seal head assembly back into the bottom of the stanchion according to Rockshox's instructions.
NOTE: Make sure the Luftkappe piston is close to or touching the sealhead when you reinstall the sealhead. If it's pushed a long way into the stanchion before the sealhead is reinstalled, you can trap too much air in the negative chamber, which will result in your fork "sucking down" even when pressurised as it is not able to extend far enough to equalise pressures between positive and negative chambers.
Continue servicing the fork as per Rockshox's instructions if you are servicing the damper or replacing the wiper seals, or skip to the reassembly instructions. Follow the factory instructions for reasssembly, but do not repressurise yet.
Note: ensure footbolts are done up with the fork fully extended. If they're done up with it partly or completely compressed, the fork will suck down into its travel.
Reinstall onto the bike once reassembled and checked.
Your token configuration should start with two tokens less than you had previously. The maximum number of tokens you can safely run is ONE LESS than what is specified by Rockshox for the configuration of fork you have, when it is in stock guise.
Your starting air pressure should be approximately 10% higher than your air pressure was before installing the Luftkappe, however we need to get there in two or three steps.
a) Pressurise the fork to roughly 1/3 of the final pressure you are aiming for. You will notice the fork is now very stiff at the start of the travel, and is topped out very hard.
b) Compress the fork several times, very slowly, to allow pressure to equalise between the positive and negative chambers. You will feel a soft notch in the motion near the start of the stroke - if you hold the fork at that position you will feel it get softer over the space of a few seconds.
c) Once the two chambers are equalised fully, the fork will top out pneumatically (not hard contact between two surfaces).
d) After the two chambers are equalised, pump the fork up to roughly 2/3 the pressure you are aiming for and repeat the equalisation process there.
e) Repeat equalisation process at full pressure.
Ride your bike and adjust pressure and volume configurations as you see fit.
After installing my Luftkappe, the fork is not extending to full travel, what is happening?
After installation, the fork should extend to within about 2mm of its original travel when the fork is unweighted (lift front wheel off the ground to allow weight of wheel to pull on fork). If it doesn't, this is a sign that one or more of the following things has happened:
1. The footbolts were not done up with the fork at full extension. This must be done or the fork will have a vacuum in the lowers that sucks it down. Undo the footbolts and tap them loose, then do them back up at full extension.
2. The piston was inserted too far into the chamber before the seal head was installed, trapping a lot of air in the negative chamber that the air in the positive chamber is not able to overcome in order to reach the equalisation port. You can try forcibly extending the fork to reach the equalisation point, and/or use higher pressure in there to assist you. If it does equalise but still stays sucked down, this is not the cause.
3. You do not have the correct air shaft in there. If you have changed the shaft, this is very likely the cause - there are multiple variants of a "150mm" air shaft for example, depending on your wheel size and which fork you have (Lyrik/Yari or Pike). Replace the shaft with the correct one.
4. There is excessive grease in the negative chamber, or the topout bumper was not removed. Make sure these are removed.
5. There is some fault with the main piston quad ring that is preventing it from sealing properly, such as debris jamming in between it and the stanchion. This will typically cause complete collapse of the fork.
6. You are reading the wrong sag gradients. This happens to the best of us!
I can forcibly extend my fork about 20mm past where it extends to before it hits a hard stop, what's going on?
This is pneumatic topout in action - topout bumpers are not necessary in this fork. Being able to forcibly extend it a considerable distance past its proper topout point is normal and will not occur in use.
My fork sags just under the weight of the bike, why?
It should sag a couple of mm, because the bike has weight. If your suspension does not sag at all under the bike's weight then it is excessively sticky or preloaded. Think about it this way - if you, the rider, weigh 90kg (200lbs) and the sprung mass of your bike weighs 10kg (22lbs), your bike's sprung mass constitutes about 10% of the total sprung mass. If you run approximately 20mm sag in the fork when the rider is on the bike, then it makes sense that you'd see roughly 2mm sag with no rider on the bike.
I have to run more pressure now to get the same sag, why?
Part of the point of the Luftkappe is that it reduces the initial stiffness of the air spring. As a result, yes, you'll run more sag. Besides that, measuring sag on a fork is very inconsistent and unreliable - use pressure as a measurement instead. If the fork feels like it's riding too low in the travel due to the extra sag, it may simply be that your handlebars need to be a few millimeters higher.