15. With all front-end parts of the bike installed, check again for proper
headset tightness by engaging the front brake and rocking the front of
the bike back and forth, looking for knocking in the headset. If needed,
loosen the upper crown bolts, tighten the headset top cap, and repeat
the relevant portions of step 11 to remove any play in the assembly.
AIR PRESSURE FILL PROCEDURE
1. Unthread and remove the negative air chamber cap found on the
bottom of the spring leg.
2. Attach a high-pressure, suspension specific pump to the valve and
using the pump’s bleed button, remove all pressure. Remove the pump.
3. Locate the positive air chamber cap at the top of the spring leg.
AIR SPRING SETUP
The Bartlett uses MRP’s FulFill™ air spring system with independent
positive and negative chambers. It is critical the you follow the steps
below in order for proper suspension function.
Because the Bartlett is a high-performance fork and its desired
feel is highly subjective, we recommend experimenting with different
air pressure settings in conjunction with Ramp Control settings and air-
volume modifications (using the included Huck Pucks).
In testing, we’ve found that the common usable range for air
pressure is between 90-200 PSI. A good starting point for most riders
seems to be a positive pressure (in PSI) equal to approximately
65-70% of body weight in pounds (lbs.). For example, a 175 lb. rider
should start with 118 PSI in the positive chamber. Most riders like slightly
more pressure in the negative chamber. You may inflate the negative
chamber to as much as 10% or 10 PSI (whichever is greater) more than
the positive chamber.
If you are unfamilar with lbs. (pounds) the conversion from kg.
(kilograms) is:
kg. x 2.2 = lbs.
Here are some examples:
RIDER WEIGHT
150 lbs. / 68 kg.
175 lbs. / 79.5 kg.
200 lbs. /91 kg.
225 lbs. / 102 kg.
POSITIVE PRESSURE
101 PSI
118 PSI
135 PSI
152 PSI
NEGATIVE PRESSURE
105 - 111 PSI
122 - 130 PSI
140 - 149 PSI
158 - 167 PSI
IMPORTANT BRAKE INFORMATION:
THE BARTLETT FORK FEATURES A POST MOUNT FOR 180mm
ROTORS. SHOULD YOU WANT TO USE A LARGER ROTOR, MAKE
SURE TO USE THE APPROPRIATE DISC BRAKE ADAPTOR AS
RECOMMENDED BY YOUR BRAKE MANUFACTURER. FAILURE TO DO
SO COULD RESULT IN SERIOUS INJURY OR DEATH.
Unthread and remove the positive air chamber cap and attach a high-
pressure suspension specific pump to the valve.
4. Fill the positive air chamber to the desired pressure. Remove the
pump and re-install the positive air chamber cap.
5. Return to the negative air chamber; attach the pump, fill to the
desired pressure, remove the pump, and re-install the negative air
chamber cap.
RAMP CONTROL™ ADJUSTMENT
Ramp Control gives you the ability to
adjust, on-the-fly, the air spring’s ending-stroke
curve. Ramp Control is completely independent
of your damper or air spring pressure settings.
All MRP forks feature super-supple small-bump
compliance, but with Ramp Control you can set
your fork up to be super plush but still resist
bottoming. Cadillac-plushness not your thing? Dial back the Ramp
Control and up your pressure to enjoy a more linear fork that rides high
but uses every inch of travel effectively.
HUCK PUCK (AIR VOLUME) TUNING
The Bartlett comes stock with two Huck Pucks installed. You may
install as many as 5 total (3 additional) Huck Pucks. The installation of
Huck Pucks reduces the volume of the positive air spring and thereby
changes the overall spring curve. With additional Huck Pucks, the
biggest change occurs at the end of the stroke, where it becomes
more progressive (less susceptible to bottom-out). This change in
performance occurs at all compression speeds, where the Ramp
Control function mostly increases ending-stroke ramp on high-speed
compression events.
HUCK PUCK INSTALLATION OR REMOVAL
1. Release all air pressure from the negative air spring by depressing the
Schrader valve core on bottom of the air leg of the fork. Fully open the
Ramp Control adjustment and repeat the same for the positive spring
(at the top of the air leg of the fork). To ensure all air is released from
both chambers, cycle the fork 2-3 times and depress the positive valve
core again.
2. Use an 11mm socket to remove the lock nut on the positive spring’s
schrader valve and allow for removal of the Ramp Control knob and
The Ramp Control cartridge assembly is located at the top of the spring-side
fork leg, and adjusted via a 16-position knob there. Clockwise adjustment
of the knob will reduce the forks tendency to bottom-out on hard hits and
increase the ending-stroke spring curve.