Performing a Helm MKII Travel adjustment is a straightforward process. If you would like to follow along in video format, please watch our video located here:
Step 1: Clean the entire fork before beginning service. This will prevent any contaminants from making their way into your fork.
Step 2: Remove the protective caps from the top and bottom of the fork on the left leg.
Step 3: Unthread the negative air spring charge button. With the charge button depressed, remove all of the air from the schrader valve at the top of the fork. This will ensure that all of the air has been removed from both the positive and negative air chambers.
Step 4: Use a 13mm wrench to loosen, but not remove the compression rod footnut on the lower left fork leg.
Step 5: Use an 18mm wrench to loosen the rebound knob assembly. Do not completely remove it yet.
Step 6: With both the compression rod nut and rebound assembly loosened, it’s time to remove your fork lowers. Firmly push on the compression rod nut and the rebound knob assembly to disengage the lowers. Note: this interface has tight tolerances and is a tight fit. Some force may be required, and it is okay to do one at a time. Do not use a hammer.
Step 7: Completely remove the compression nut and the rebound knob assembly.
Step 8: Lay the fork down flat, arch side down on a protected surface. Grab the upper crown assembly and lower assembly with each hand, and carefully separate them. Leave the lowers laying face down to prevent any oil loss. If oil is lost, you can add some later in the process.
Step 9: Press the negative air spring valve button and depress the negative air spring into the fork to prevent any risk of scratching it. We recommend securely mounting the fork uppers vertically in a bike repair stand to better access the air seal head.
Step 10: Use a pick to carefully remove the retaining C-clip from the air spring stanchion tube.
Step 11: With the C-clip removed, carefully slide the air spring up the stanchion tube. You do not need to pull it all the way out.
Step 12: Once you have exposed the air piston, you will be able to adjust your travel.
At this point, you will be able to make any adjustments you wish to make to your travel. Adding spacers will reduce your travel, and removing them out will add to your travel.
Each travel spacers adds or subtracts 10mm of travel
HELM Air MKII 29/27.5+: 100mm - 160mm
HELM Air MKII 27.5: 100mm - 170mm
There are two types of travel spacers. Volume adjustment spacers (black) and travel reducing spacers (red).
Standard Travel Spacer part number: HELM Travel Reduction Kit – 2x10mm – BAG0392
To reduce the travel, add the desired amount of travel reducing spacers (red) between the white nylon washer and the air spring’s piston. To add to the travel, reduce the number of red spacers by the preferred amount.
Be sure to not block the negative air spring charge ports located on the air piston while doing this.
Step 13: Apply a light coating of grease to the air seal head before reinstalling.
Step 14: Reinstall the travel adjusted air spring assembly into the stanchion tube until the seal head is past the retaining ring bore.
Step 15: Install the retaining ring - start with one end in, and work your way around. Make sure that the retaining ring is installed correctly and completely by depressing the negative air spring valve button and pulling the piston to full extension.
Step 16: Inspect the o-rings on the end of the rod assemblies. Replace if necessary.
Step 17: Fully closing the high speed and low speed compression adjusters, and adding a fresh coat of suspension grease to the wiper seals will aid in reassembly.
Step 18: Note the orientation of the flanges on the bottom of the lowers, and align the flanges on the compression rod and damper rod to the lowers.
Step 19: With the lowers still laying face down on a protective surface, carefully feed the stanchions into the lowers. Work the stanchions past the wiper seals, and ensure that the wiper seals are not folded or bound in any way. You do not need to push the lowers all the way on yet.
Step 20: If any fork oil from the switch was lost, now is the time to replace it. We recommend using 15w Moterex racing fork oil. 5ML in the air spring side, and 7ML in the damper side. Ensure proper alignment of the both compression rod and damper rod within the lowers - Realign compression rod and damper rod flanges if necessary.
Step 21: Use blue Loctite on both the compression rod nut and the rebound knob assembly.
Step 22: Compress the fork until you can tighten both nuts. Tighten the compression rod nut to 5Nm and the rebound knob assembly to 7Nm.
Step 23: With your travel adjust completed, add your desired PSI to the forks air spring, and remember to charge your negative air spring. Charging the negative air spring can cause a drop in fork PSI as it spreads to a larger volume, so doing this twice can be worthwhile for optimal setup.
Step 24: Remember to reinstall your protective caps.
Step 25: Install the fork on your bike, and go out and ride!