Exxentric kBox4 Active User manual

kBox4 Manual
Version 9.5, September 2020
Pro, Lite & Active

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Please read and understand the user manual and warning labels prior to use.
Inspect the machine including the drive belt before use. Damaged or worn parts and warning
labels must be replaced. See user manual for how to change and cut the drive belt. Do not modify
the machine or repair it with non OEM parts.
Never step off the kBox while the flywheels are moving. Make sure the flywheels come to a
complete stop before you end the exercise, disconnect, or step off.
The kBox can deliver a supramaximal* workload. Do not exercise at an intensity you cannot
manage.
Work out at a submaximal** intensity until you are familiar with the equipment.
Do not let the pulley block hit the kBox, absorb the eccentric load before it hits the kBox.
Make sure the pulley block snap shackle is properly closed and connected before you start training.
If you feel dizzy or experience pain, stop exercising immediately.
Exxentric takes no responsibility for any injuries that may occur.
Keep away from moving and/or rotating parts.
This machine and accessories are intended for strength training only. Do not use it in any other way.
Exercising at maximum intensity may cause temporary staggering and uncontrolled body
movements due to fatigue. Exercise caution to prevent falling.
The machine might get slippery when wet. Use clean shoes and dry off the machine with a cloth if it
is wet. Shoes with spikes, dirt, stones can damage the rubber surface of the kBox.
Flywheels may get slippery when wet. When lifting flywheels, use a secure two-hand grip.
Never stop an exercise in top position.
Both feet have to be placed on the kBox during exercise if it’s not fixed to the ground.
Use shoes to avoid friction burns from the spinning flywheel or drive belt during use. Never stop a
spinning flywheel with your bare hand as it may cause friction burns.
Always place the kBox on its feet on level ground or floor surface during use.
If you have balancing problems, be sure to have support by a spotter or fixed object like a wall.
The device is not suitable for children or animals.
*) Supramaximal means higher than maximal. This means higher loads than your muscle can
produce themselves in a shortening (concentric) action.
**) Submaximal means below maximal. In this case, we would recommend below 75% of max
intensity.
PERSONAL INJURIES MAY OCCUR IF THESE PRECAUTIONS ARE NOT OBSERVED

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Like any exercise program, it is important that users are capable
of performing exercises on this exercise equipment and have
verified this with their personal physician.
This Manual covers a description of the Kinetic Box,
or kBox, a Multi-Exercise Flywheel Device, a guide to
its use, and how to maintain it.
Always check exxentric.com/support for latest info and
manuals.
CONTENTS
Caution!
Specifications 6
Introduction 7
Features 12
Usage 14
Flywheel Workout Zones 18
kBox4 Maintenance 19
kMeter 21
kBox4 Accessories 22
Support 23
Warranty 24

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SPECIFICATIONS
Active Lite Pro
Minimum dimensions (bounding
box) - fully assembled
Width 76 (30") 76 (30") 98 (38,5")
Depth 51 (20") 51 (20") 63 (29")
Height 21 (8.5") 21 (8.5") 23 (9")
Top surface in cm (inches)
Width 68.5 (27") 68.5 (27") 90 (35.5")
Depth 43.5 (17") 43.5 (17") 55 (21.5")
Area (m) 0.29 0.29 0.50
Materials
Chassis steel aluminium aluminium
Flywheel steel steel steel
Color bronze brown, blue, black brown, blue, black
Features
kMeter II built-in optional* yes yes
Drive belt auto-retract yes yes yes
Quick change flywheel yes yes yes
Foot block option** yes yes yes
No. of flywheels mounted 1-2 1-4 1-4
Inertia range kgm0.005 - 0.10 0.005 - 0.20 0.005 - 0.28
Inertia factor (min to max) x20 x40 x56
Angle adjuster yes yes yes
Flywheel options (kgm2)
XS - 0.005 yes yes yes
S - 0.010 yes yes yes
M - 0.025 yes yes yes
L - 0.050 yes yes yes
XL - 0.070 - - yes
Weight of machine 15 kg (33 lbs) 9.5 kg (21 lbs) 15.5 kg (34 lbs)
Maximum weight allowed on kBox 200 kg (441 lbs) 200 kg (441 lbs) 200 kg (441 lbs)
*) Active is kMeter II ready. It can be pre-installed from the factory or later by the customer.
**) Pro has a larger platform and more positions for individual adjustment of the foot blocks. Included with
kBox4 Active, Lite and Pro platforms: angle adjuster, attachment kit, tool kit, printed manual, spare drive belt,
flywheel protection for mounted flywheels, built-in kMeter II (Lite and Pro only).

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kBox4 manual v9.5
INTRODUCTION
kBox4 - Top surface overview
kBox4 - Bottom overview
Color of parts may have slight variations depending on batch.

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What is the kBox4?
How does it work?
Setting up the kBox
The kBox4 is a self-contained, compact exercise
platform for various strength movements. It is a
multi-exercise flywheel device and uses the moment
of inertia to provide a high and variable resistance in
both the concentric and eccentric* movements of the
user.
*) Concentric muscle action is when the muscle is being shortened
during action and an eccentric muscle action is when the muscle
is being elongated during action. In some literature, concentric
and eccentric are called positive (shortening) and negative
(lengthening) phase.
The kBox has an adjustable-length drive belt wound
around a shaft located beneath the platform.
Different combinations of flywheels are mounted on
the end of the shaft.
Using hand grips or a harness attached to the pulley block, the
user pulls to accelerate the flywheel, then resists to decelerate the
flywheel as the belt winds in the other direction.
All kBox4 models have a recoil auto-retract system. The drive
belt length adjustment button allows for quick adjustments of
the belt length for the type of strength work desired. Push the
button to release and adjust the length or just push the button to
automatically retract the belt. An extension belt is used for overhead
exercises, for example, military press.
If training without both feet on the kBox4 is
anticipated, the platform must be attached to the
floor or weighted down so it cannot move. Gradually
from May 2019, the Flywheel Knob is fixed to a holder
under the kBox4 when shipped.

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The Flywheel There are five differently sized flywheels, with inertia
0.005, 0.010, 0.025, 0.050, and 0.070 kgm2.
They all fit the kBox4 Pro and all but the 0.070 kgm2fit the kBox4 Lite
and Active. You can mount up to four flywheels on the kBox4 Lite
and Pro, and two flywheels on the kBox4 Active.
Do not try to mount more than the maximum capacity of
flywheels.
Experimentation will determine which configuration is required for
your level of training. Mounting or changing flywheels is done by
releasing the flywheel knob by pulling the pull pin knob on its side,
removing the flywheel knob, changing flywheels and securing them
by pushing the flywheel knob back on until it makes a clicking noise.
Tip! If the black pull pin knob is hard to pull out you can push
the flywheel knob in whilst pulling the black pull pin knob out.
Floor Attachment Kit The floor attachment kit consists of an attachment
plate and a cam lock belt*.
This package is included with all models and can be used for
attaching the kBox4 to the floor. The attachment plate will need to
be fixed to the floor or a heavy wooden board. The kBox4 will then
be anchored to the plate by the belt. On newer kBox4 models there
are two additional slots in the corners for attaching the kBox4 to the
ground. To use the two slots you will need to purchase a second
floor attachment kit.
*Note that from May 2020, the cam lock belt can also be used as
an extension strap.

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Flywheel Protection
Foot Block
The flywheel protection has to be assembled after
unpacking the kBox4.
This is highly recommended in order to protect against injury. First
remove the plastic film, then bend and hook the cover under the
bottom of the kBox4 and then in the holes in the front of the chassis.
See pictures below.
The foot block can be positioned straight or with an
angle and is secured by sliding the pins into the holes
in the front and the back of the kBox4 chassis.
Use the side with the lower angle for lateral movement and the
other side if you just want to maintain foot placement during
vertical work.

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Angle Adjuster The angle adjuster allows for more horizontal actions
in training (e.g. bent over row, swings).
Just thread the drive belt through the top of the angle adjuster and
snap it on. The location for the placement is indicated with a sticker.
The link below will lead you to a video showing the angle adjuster in
use. The angle adjuster is included with every kBox4.
https://bit.ly/2YzZQVc

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FEATURES
The kBox is a ‘multi-exercise flywheel device’. Which
muscle is being exercised depends on which exercise
is being performed.
The principle is that through muscle force you accelerate and
decelerate a flywheel (or flywheels). Exercises with high intensity and
high forces stimulate muscles to increase in size and the nervous
system to increase activation of the muscles. These effects together
increase strength over time if the exercise is repeated regularly.
Resistance
Principle of the kBox
Eccentric loading
The resistance is variable and unlimited.
The flywheel has a specified inertia and there is no upper limit to
how much kinetic energy you can produce in the flywheel motion.
You can think of the flywheel as a weight that weighs more if you
put more effort into lifting it. Resistance is variable so if you pull less,
the flywheel will resist less.
Every repetition in al set can be maximal instead of only the last
one, which is the case with traditional weights. This results in a
higher training efficiency, earlier onset of strength increase and
hypertrophy*.
The potentially higher exertion on the kBox may lead to a need for
longer resting periods between sessions to fully recover.
*) Hypertrophy refers to an increase in muscular size achieved
through exercise.
The kBox4 provides for increased eccentric workloads.
The skeletal muscles can produce more force in the eccentric, or
negative phase. This is difficult to take advantage of with traditional
weights, which always weigh the same.
If you accelerate the flywheel during the concentric, or lifting phase
and then decelerate in a shorter amount of time, you will have
to produce a higher eccentric force. This will be similar to lifting
weights that would normally be too heavy to lift, unless assisted
by a training partner, but executing the eccentric (lengthening)
phase by yourself. Check the training guide for more information on
eccentric overload.

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The kBox4 is mobile in comparison to traditional
weights.
Squatting with the kBox4 is equivalent to traditional squats which
would require a barbell and weights up to or beyond 500 lbs (227
kg) for a strong lifter, which is practically impossible to carry around.
In addition, with the kBox4 you don’t need rubber mats or racks.
Furthermore, you do not need spotters to be able to do a 1 RM
(one-repetition maximum). All of this is possible with the kBox4
which weighs about 22 kg (48 lbs) with one flywheel included and it
can be carried and transported easily in an ordinary car. The kBox4
Lite can even be checked in as luggage when flying.
Ergonomics
Mobility
User environment
Pressure on the shoulders and upper back is a limiting
factor for many poeple when performing traditional
barbell squats.
Serious bruising can be seen after heavy sets. Furthermore, the
lumbar spine discs are under a lot of pressure, even if the athlete
has good technique. With tall people, people with a weak core, or
back problems, squatting is almost impossible or accompanied
with a lot of discomfort or pain. With the kBox4, you are able to work
out maximally or closer to maximum intensity since the harness
distributes the pressure over the shoulders and reduces the
pressure and torque on the lumbar spine.
The kBox4 is quieter when training. The area does not
have to be equipped with sound reducing materials.
There is a much lower risk of collision, meaning more people can
work out in a smaller room without the risk of interfering with each
other and causing injuries.

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USAGE
Whenever you use the kBox4, make sure to absorb
all the energy in the downward phase and come to a
complete stop before the pulley block hits the kBox4
since this will cause damage to the device.
Foot placement
Important
Using the Harness
Feet are placed differently depending on which
exercise you are performing.
Make sure the drive belt goes smoothly into the device and
reposition yourself if it goes against the edges or twists. Use the
foot block for restricting your stance, lateral push movements or
heel support during calf press. Weigh down the kBox4 or use an
attachment plate if you are not standing on the device with both
feet.
Attach the harness to the pulley block with the
harness ends turned inwards (red double-stitched
sides towards each other) which is more comfortable
against the thigh.
Make sure the snap shackle is properly closed before you start
training. The pin in the release function must go through the hole
in the clasp completely, as seen in the photo to the left. The snap
shackle makes it possible to have an emergency release, just
attach a cord in the snap shackle pin for the athlete or trainer to
hold and pull to release.
Be sure the harness fits well and is not too loose (various sizes are
available). It should not slip down over the shoulders. The upper
chest strap can be loose but the bottom strap has to be more tight
for best use.

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Use the red drive belt length adjustment button to
set the belt length to allow the belt to fully reach the
upper end of the exercise movement.
For beginners and rehab patients doing lower body exercises,
the top position should be just before all active joints are fully
extended. For experienced users, there can be some slack in the top
position to minimize strain on the belt and hook at the reversal point.
Remember not to stop the movement in an extended position
when the flywheel is spinning, as this will put strain on your joints if
hyperextended.
Bend your knees slightly and take up the slack in the belt using
your hand to rotate the flywheel and rewind some of the belt.
Next, accelerate the flywheel by starting the exercise at a lower
intensity. Accelerate the flywheel at every repetition. After two to four
repetitions you should have reached your desired training intensity.
Perform your training set, usually 6-12 repetitions at desired intensity.
Decelerate the flywheel on the way down and stop at the bottom.
Slowly return to your start position and let the flywheel stop
completely. Detach the harness, step off the platform and prepare
yourself for the next set. Make sure you get an adequate amount of
rest between sets.

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The hip belt can be used differently depending on
your preferences.
1. Place the hip belt above your hips and tighten it. Attach the
pulley block to the small loop. A solution for flexible “ass to grass”
squatters.
2. Place the hip belt on your hips and attach yourself to the pulley
block using the bigger loop on the hip belt. Only recommended
if doing squats above 90 degrees.
Note: When attaching the pulley block to the smaller loop, it enables
a spotter to hold the bigger loop in the back for extra safety or for
overload variations.
Attach the desired grip or bar to the pulley block and
position your feet as described above.
Use the drive belt length adjustment button to set the top position
for the actual exercise. As with the harness, for beginners and rehab
patients doing upper body exercises, the top position should be
just before all active joints are fully extended. For experienced users,
there can be some slack in the top position to minimize strain on
the belt and hook at the reversal point. Remember not to stop the
movement in an extended position as this will put strain on your
joints.
Put the flywheel in motion to roll up the belt. Accelerate the flywheel
by starting the exercise at a lower intensity. Accelerate the flywheel
at every repetition. After two to four repetitions, you should have
reached your desired training intensity.
Perform your training set, usually 6-12 repetitions.
Decelerate and stop the flywheel on the way down. Don’t put down
the handle or grip before the flywheel(s) has come to a complete
stop. Rest accordingly.
Using the Hip Belt
Using the Grip/Bar

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Selecting inertia
Inertia will dictate the speed and hence the type of resistance training you are doing.
Lower inertia equals higher speed and lower force and, higher
power vs higher inertia. For max strength, slow and controlled
movements with high force and low speed are warranted and
hence require more inertia.
The flywheel workout zones can be helpful, if you want to read more
about this, please go to:
https://bit.ly/2NENUNE

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FLYWHEEL WORKOUT ZONES
FLYWHEEL WORKOUT ZONES
LOW MID HIGH
INERTIA
SPEED
LOW MID HIGH
POWER
WARM-UP
WARM-UP
OVERLOAD
STRENGTH
TECHNIQUE
OVERLOAD
STRENGTH
Warm-up
Technique
Higher inertia
Power
Strength
Low intensity and low to medium inertia
Medium inertia and low intensity
More eccentric overload
We want to stress that new exercises and users
should be taught using MEDIUM inertia and LOW
INTENSITY.
Since this will be slow, controlled, and submaximal forces, it is
easier to correct and less risk for injury or technical error. When the
technique is correct, increase the intensity and/or lower the inertia
for higher speed and more power.
Max intensity at low inertia
Medium to high intensity at medium to high inertia

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KBOX4 MAINTENANCE
Drive Belt cautions
Trimming a worn belt
The drive belt and its attachment to the shaft is the
most sensitive part of the kBox4. Be attentive to wear
and check regularly.
When the belt shows signs of wear and tear, trim the end by cutting
off the damaged area or replace it with an original spare drive belt.
For recommendations on how to prolong the lifespan of your drive
belt, please refer to our videos on best practices, found here:
www.exxentric.com/support/manuals/
If damage occurs close to the shaft it is possible to
cut off the damaged end and reattach the new end.
Procedure:
1. Unwind all of the belt from the shaft.
2. Use the 3 mm hex key to push the belt through the shaft and
remove the lock pin.
3. Cut off the damaged belt. Harden the new end with a lighter.
4. Fold the belt around the lock pin and pull the belt and pin into
the wider groove in the shaft.
5. The belt automatically locks into the groove when you pull it
firmly.
For a video tutorial, please go to:
https://exxentric.com/support/maintenance/trim-
belt-kbox4/

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Replacing the Drive
Belt
Maintenance of
screws
Maintenance of
the Shaft
Toolkit
(found on shaft cover
underneath the kBox4)
Follow the steps below to complete the replacement:
1. Detach the drive belt from the shaft by pushing out the lock pin
using the 3 mm hex key.
2. Remove the pulley block and make a knot on the drive belt.
3. Push the belt adjustment lever and pull the free end of the belt
through the opening in the platform.
4. Flip the kBox4 over. Pull the belt out from the auto retract until
you see the metal hook. Disconnect the old belt and fix the hook
onto the kBox4 chassis so the spring can’t retract.
5. Remove the old belt completely. Take a new belt and attach it
to the metal hook and let it slide gently into the auto retract.
6. Thread the free end back through the hole in the chassis and
the locking mechanism and make a knot.
7. Flip the kBox4 back.
8. Put the belt through the pulley block and lock it in the shaft with
the lock pin.
For a video tutorial, please go to:
www.exxentric.com/support/maintenance/replace-
belt-kbox4/
The kBox4 center parts (shaft, bearings and flanges)
are subjected to heavy and repeated forces.
We recommend that you inspect the screws and tighten them
quarterly.
For a video tutorial, please go to:
www.exxentric.com/support/maintenance/
Apply a spray lubricant to the shaft within 8 weeks of receiving your
kBox4 and then once every 6 months. The frequency of applying
rust protection will increase if you have your kBox4 in a more humid
environment.
Note: Newer versions of the kBox4 come with a stainless steel
shaft and do not need rust protection.
3mm Hex key
(used for flanges/shaft position screws and to remove lock pin)
Extra lock pin
(for drive belt)