Huka orthros User manual

version 04/21
Huka makes your world easier www.huka.nl/en
MANUAL
Duo bike
Orthros
Orthros
MANUAL
Duo bike
Orthros
Orthros

2
Your notes
Extend your
standard warrantly
to 10 YEARS
VIA WWW.HUKA.NL/
en/warranty

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www.huka.nl/en
Would you like to cycle carefree? With your Orthros we want to make your world
easier. You would probably rather go cycling than read the manual. That is why we
have put together a manual that contains the most important and necessary
information about the safe use of the Orthros. Please read this manual thoroughly
before using the Orthros and always follow the instructions given in the manual.
To make the best use of your tandem, I will sometimes give you a few advices so
that you can continue to cycle safely and have fun.
We are curious about your experiences and where you like to ride. Would you like
to share it with us on Facebook? We love to hear from you!
We wish you lots of cycling fun!
Kind regards,
Kevin Verduijn
Maker of the Orthros
Congratulations on your new Orthros

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Contents
General
Indication & application
Warranty
EU Declaration of conformity
First bike ride on Orthros
Safe on the road
Boarding and cycling
Brakes
Pedal assited bicycles
Battery indication
Moving and carrying the duobike
Product description
Bicycle frame
Drive unit
Wheels and tyres
Spokes
Chaincase and chain
Brakes
Crankshaft, crankset and pedals
Gears
Seat
Steering
Multi-adjustable handlebars
Lighting
Luggage basket
Electric pedal assistance
Pass Vario pedal assistance
Accessories
Securing components
Stuur
Wielen
Bandenspanning
Beste onderhoud Country
Specificaties
Country 22
Country 24
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Optimal use
Adjust seat depth
Turn the seat
Adjust steering angle
Adjust steering height
Adjust steering stem angle
Wheels
Tyre pressure
Best maintenance Orthros
Cleaning
Tyre pressure & tread
Bonding
Spokes
Chain
Brakes
Lighting
Battery charging
Replacing components
Specifications
Others
Contact details Huka
Changes
Removal of product
Selling the duobike
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www.huka.nl/en
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Indication & application
The Orthros is specially designed for people who need extra support in order to enjoy
stable and safe cycling. This may be because you would like to experience more
stability or, for example, because of a neuromuscular disorder that can affect your
coordination or natural movement possibilities. The duo bike is also used for people
who want to cycle together! The Orthros is designed to be used on normal public
roads and cycle paths.
•The Orthros complies with all laws and regulations applicable to the use of
public roads. The use of the Orthros as a racing or cross bike falls outside
the intended area and responsibility of Huka.
•It is your responsibility to act according to the specific safety requirements
of the country you are cycling in. This also applies to possible insurances
according to the relevant legislation including a correct outfitting of yourself
and your duobike that the country in question requires.
•The driver must be independently mobile and may not have any physical or
mental challenges that make safe participation in traffic impossible, such as
an (audio) visual impairment.
Warranty
Huka offers a standard 5-year guarantee on the frame and front fork of your
Orthros. You also have a 2-year guarantee on the battery and other parts. All
warranties are handled by your Huka dealer.
•The guarantee does not apply to damage or defects to the Orthros that
have been caused by wrong or injudicious use. The assessment of this lies
with Huka B.V. or a representative to be appointed by Huka B.V.
•The guarantee does not apply to parts subject to wear and tear, such as the
chain, brakes and tyres.
•Under no circumstances shall Huka be liable for any special or
consequential damages due to the negligence of the user of the Orthros.
Even if Huka has been informed about such damages.
General

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•Applicable law may not allow the limitation or exclusion of liability or
damages. Therefore, the above limitation or exclusion may not apply to you.
•The warranty and product liability in general may expire if instructions in this
manual have not been followed. This is the case when maintenance work,
technical changes, or additions to the bicycle have been carried out with non-
original Huka parts without Huka's permission. It also means that the CE-
marking has expired. The lack of a CE-declaration can lead to problems with
the insurance of the bicycle and with possible damage or liability.
Location identification sticker
Sleeve number
Frame number
ADVICE FROM KEVIN Please write down the frame and key number of
your Orthros. The number is important for guarantees, repairs or in case
your bike is stolen to report to your insurance company. You can find the
number on the frame tube under the right seat.
www.huka.nl/en
Example identification sticker

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EU Declaration of Conformity
Supplied under the sole responsibility of the manufacturer:
Huka B.V.
Munsterstraat 13, 7575 ED Oldenzaal, Netherlands
Hereby declares that the following device:
Registered trade name:
Product type:
Risk class:
SRN:
Orthros
Duobike
Class 1
NL-MF-000003494
To which this declaration relates, is in conformity with the following Regulations:
Regulations (EU) 2017/745 of the European Parliament and of the Council of 5 April
2017 (MDR).
And with the CE mark which can be identified from the:
labels on the tricycle's main frame and illustrated in the Warranty section of this
manual.
Signed on behalf of Huka,
R. Lotgerink,
Managing Director
Datum: 15 april 2021

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www.huka.nl/en

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First bike ride on Orthros
The time has come. Your first experience on your own Orthros! Whatever bike ride
you do, your safety comes first! If it is your first time cycling on a Huka companion
cycle, you may have to get used to it. The most important tip we can give you is
that you should relax as much as possible while cycling. To make sure everything
goes as smoothly as possible, we give you a number of instructions.
Safe on the road
Apart from your dexterity on the Orthros, which will improve as you use it, it is
important that the duobike is in optimum condition when you go out on the
road. We recommend that you take the following aspects into account:
•Before each use, check the condition and operation of the brakes, tires, rims
and steering system.
•Keep in mind that the braking characteristics change and the braking distance
may increase when the road surface is slippery.
•Make sure that possible luggage is securely fastened and cannot shift.
•Ride on flat and firm surfaces and avoid deep potholes, high thresholds and
puddles of water and slopes with more than an 8% incline.
•Ride at appropriate speeds on wet or slippery surfaces, slopes or chasms. Do
not bump into curbs.
•Always lock the duobike when parking it. Use the parking brake to prevent
possible runaway.
•The Orthros is largely made of steel which is considered non-flammable. The
other materials used such as plastic, rubber and parts like these are not
fireproof.
•When pulling away on a steep slope, lean forward if necessary to prevent the
front wheel from lifting or skidding. When reversing on a slope, brake
carefully until you come to a stop.
ADVICE FROM KEVIN Make sure that the handlebars and seats are
properly adjusted before you start cycling. This way, you can assume the
correct position on the bike.

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ADVICE FROM KEVIN When changing gears, make sure you stop
pedalling and choose the desired gear. Do not continue pedalling when
changing gears. This can cause damage to the gearshift mechanism.
Damage to the gear hub as a result of abuse is not covered by the
warranty.
Boarding and cycling
Always use the parking brake when getting on or off the bike, so that the bike
will not move. The passenger seat can be turned outwards to make it easier to
get on. Put it in first gear (if necessary), so you can pedal more lightly. As soon as
you sit down and want to cycle, take the duobike off the parking brake.
•When standing up, lift both feet and place them side by side in front of
the chair. Then sit down slowly.
•Stay upright at all times and keep your feet on the pedals. Even when
you brake or stand still.
•Descend a slope at a moderate speed so that you can always come to a
stop in time and in a safe manner.
•Do not exceed the maximum weight as stated in chapter Specifications'
section.
•Wear an appropriate bicycle helmet.
•Wear reflective clothing to increase visibility on the road.
•When the Orthros is used by children or young people, we recommend
never letting small children ride alone in public traffic.
•Before setting off, check that the lights are working and replace the
batteries on time.
ADVICE FROM KEVIN When cycling, steer with your arms and not with
your body. Cycling into corners takes some getting used to. In order to
maintain stability, lean your body slightly towards the inside of the bend.
Adjust your speed accordingly. Avoid sudden and violent steering
movements. In this way, you can avoid accidents and damage.
www.huka.nl/en

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Pedal assisted bicycles
If your Orthros is equipped with pedal assistance, the electric motor is activated
as soon as you start pedalling. Pedalling then becomes lighter. If you stop
pedalling, the pedalling assistance stops as well.
•The support can be set at different levels using the arrow keys on the
handlebar.
•To activate the pedal assistance, press the 'Mode' button for 3 seconds.
•To switch off the pedal assistance, press and hold 'Mode' for 3 seconds.
Brakes
The brakes of the duobike are operated by the main driver. The co-driver has
no brakes. Depending on the chosen brake system, we give some instructions on
the different brake possibilities.
•Back pedal brake: By stopping pedalling forwards and then pedalling
backwards, the back pedal brake is activated. It works via the layshaft on
both rear wheels. This function is optional on the duobike.
•Handlebar brakes: braking is done by squeezing both brake levers on the
handlebars. The left hand brake operates the front wheel brake. The right
hand brake operates the brakes of both rear wheels. When cornering, it is
best to use the hand brake. Practise braking in a large enclosed area
before you hit the road.
Be careful with the front brake when cornering. Using only the front
brake in a bend can cause instability of the duobike. This can lead to
personal and/or material damage.
Always use the parking brake when getting on or off the bike. This
prevents the pushchair from rolling away. This reduces the risk of
falling.
A detailed explanation of the pedal assistance can be found in the Heinzmann
manual provided.

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Moving and carrying the duobike
To move or carry the duobike, grab the rear frame tubes and the front head
tubes. We recommend that a minimum of three people should lift the duobike.
Hold the handlebars tight while lifting to prevent the front wheel and handlebars
from turning and possibly causing injury.
Control buttons
With pedal assistance and drive help
The start-up aid is intended to make it easier to get
going from a standstill. By pressing and holding the up
arrow button, the drive assist is switched on and the
motor will drive up to 6 km/h without you having to
join it. When you release the arrow button, the drive-
assist will stop immediately.
Battery indication
If your Orthros is equipped with pedal assistance, the
display will indicate how full the battery is. Check
whether the battery is full when you
(longer) distances. The black block gets shorter as the
battery gets emptier. When the block is completely
black, the battery is full. There is also a battery
indicator on the battery itself.
Exposure to bright sunlight can make various materials very hot.
The product contains moving parts. These include the steering wheel,
wheels, etc. Be alert to the danger of crushing.
www.huka.nl/en
Battery display

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Product description
bicycle without
differential
Huka bike with
differential
Your Orthros consists of several parts. The most important parts are described in
this chapter.
Bicycle frame
The Orthros frame consists of a tubular metal construction complemented by
aluminium and stainless steel components. Most of the metal parts have been
phosphated and then given an impact-resistant powder coating. This
construction and finish guarantee years of cycling pleasure.
Drive
The duobike has its own specially designed drive system on the rear wheels. This
drive (by means of a differential) ensures that the duobike does not tilt and that
bends can be taken easily.
Due to the differential both rear
wheels are driven independently from
each other. This makes the bike go
straight ahead and turns are easier to
take.
Wheels and tyres
The wheels are equipped with quality hubs, stainless steel spokes and an
aluminium rim. A-quality anti-puncture tyres are mounted on these rims.
These provide good grip, low rolling resistance and less wear.
ADVICE FROM KEVIN Regularly check tyre pressure and tyre wear to
ensure safe cycling. Tyre pressure and tyre wear has a major influence on
how your bicycle behaves.

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Spokes
A correct tension of the spokes ensures a stable duobike. Because of the
functioning of the new spokes, the wheels of your Orthros should be checked
after 200 kilometres or 2 months. Your Huka dealer can take care of this. Should
a spoke break or become loose, please also consult your Huka dealer.
Chain case & chain
The chain guard is specially designed for the Orthros and is made of impact-
resistant plastic. impact-resistant plastic. This chain guard protects the chain
from dirt and water and also ensures that the chain cannot dirty your legs or
clothing. With a good chain tension, your Orthros will pedal lightly and you won't
hear the chain. If you notice that the chain is too slack, have it adjusted by your
Huka dealer.
Brakes
The basic model of the Orthros has V-brake in the front wheel and disc brakes on
the rear wheels. These brakes are operated by the driver of the bike by means of
brake levers on the handlebars. An extra back-pedal brake that operates the rear
wheels is optional.
TIP
ADVICE FROM KEVIN In time, brakes can wear out and are very important
for safety while cycling. That is why you should have your brakes checked
regularly and, if necessary, adjusted or replaced. Your Huka dealer can help
you with this.
Always ensure that the parking brake is activated when getting on or
off the bike. This prevents the bike from rolling away.
www.huka.nl/en

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Crankshaft, crankset and pedals
•The bottom bracket bearings that Huka uses are completely maintenance
free and cannot be adjusted. If the bearing does get loose, go to your
Huka dealer immediately. If there is play between the crank and the
bottom bracket, take off the dust cap and tighten the underlying bolt with
a socket spanner.
•Most pedals are maintenance-free. Is there too much play? Then consult
your Huka dealer. When assembling the pedals yourself, pay attention to
the indications L (left) and R (right) on the pedal axles. You turn the left
pedal counter-clockwise. You tighten the right pedal clockwise. To do this,
use a socket spanner or a special (narrow) pedal spanner.
•Various (modified) pedals are available as an option.
Gears
Your Orthros is equipped with gears, whereby the gear hub is located between the
pedals and the drive shaft. This is an 8-speed Nexus hub from Shimano, which has
been tuned to the Orthros. The duobike can also be delivered in combination with
an automatic reverse gear (reverse cycling is also possible). Upon delivery your
Huka dealer has checked and adjusted the gears. The explanation of the gear hub
can be found in the Shimano manual.
The seats must always be securely fastened in the lock. Check this
regularly. A loose seat can create unsafe situations.
Adjusting the gear hub is very specialistic work. This should only be
done by a Huka dealer.
Seat
In order to cycle comfortably, safely and efficiently, it is important to adjust the
seat correctly. The seats are adjustable from front to back. The passenger seat
can rotate as standard for easy entry.
Steering
The handlebars of the duobike can be made of steel or aluminium. This depends
on the model of the handlebar chosen. The handlebars can be adjusted in height,

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Luggage basket
As an option a luggage basket can be mounted on the back. Ask your Huka dealer
about this, so that the right materials can be used and the whole thing can be
assembled safely.
Remember to replace the batteries in good time to avoid dangerous
situations in traffic. Without batteries, the lights will not work. Make sure
that old batteries are disposed of properly.
If you use the luggage basket, distribute the luggage as well as possible. The
maximum load for this is 10 kg. Total maximum load Orthros : 120 kg driver
+ 120 kg passenger + 10 kg luggage = 250 kg.
angle and depth. The main driver can steer the bicycle. The handlebars of the co-
driver are fixed.
When adjusting the height, make sure that the
handlebar stem retracts enough into the frame so
that the safety marking ''MIN'' is not visible.
Multi-adjustable handlebar (option)
A good posture also depends on the correct handlebar height. The handlebar
height, handlebar angle and angle setting of the stem and handlebar can be
adjusted for this. Use an Allen key to loosen the bolts slightly and move the
handlebars to the desired position. Tighten the socket screws to the torque
indicated on the handlebar.
Lightning
The Orthros is equipped with battery-operated LED lights with low energy
consumption and long life. These are available from various shops.
www.huka.nl/en
The handlebars must always be tightened securely. Check this
regularly. A loose steering wheel can cause unsafe situations.

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Electric pedal assistance
The Orthros can be equipped with electrical pedal assistance. This means that the
double bike has an electric motor in the front wheel, a battery pack and an
electronic box on the middle frame tube. A clear display with controls is also
mounted on the handlebar.
Pass Vario pedal assistance
With the Pas Vario support, you pedal along and the pedalling is supported by the
electric motor in the front wheel. The degree of support can be adjusted with the
control buttons on the handlebars and read on the display. The tandem bike is
equipped with a 36V 11Ah Li-ion battery mounted at the back between the driver
and passenger seat.
Handlebar controls Battery display
on trolley
Always ensure that the lights and reflectors are clearly visible. The
luggage must also be properly secured. Luggage that is not properly
secured can be dangerous in participating traffic. Straps or belts should
be properly secured to prevent them from getting into the wheel.
If the pannier basket is loaded, this may affect the driving and braking
characteristics of the duobike. Modifications to the pannier basket
affect its safety and are not allowed. For example, the basket is not
suitable for attaching a trailer or a bicycle seat.
Engine in the
front wheel
Battery pack

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Securing components
It is important that crucial components of the pushchair are properly secured.
These components need to be tightened with the correct torque. The table below
shows the values for these tightening torques.
Central stem bolt 20
20
Bolt seating system
30
Rear wheel nuts
30
Wheel nuts for
Failure to properly tighten components can lead to unsafe situations.
Observe the prescribed tightening torques.
Accessoires
Your Orthros can be expanded with various accessories. Think of armrests, luggage
basket, foot box, cane holders etc. More about these options can be found on the
price list on our website www.huka.nl/en or contact your Huka dealer.
Tightening torque (nm)
as indicated on adjustable handlebars
Section
Adjustable steering wheel bolts
Footrest for co-driver
Switchable freewheel Shopping basket
handle
www.huka.nl/en

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Optimal use
When you receive your new Huka, the parts have been adjusted to your body and
to your wishes. To make sure you are comfortable, there are adjustment
possibilities for the seat system and handlebars.
Adjust the seat depth
To adjust the seat depth, the following actions apply:
1. Pull the lever to the right to release the seat.
2. Adjust the seat to the desired position by moving forwards or
backwards.
3. Release the lever and, if necessary, move the seat slightly back and
forth so that the lock is audibly and noticeably engaged.
Turn the seat
The co-driver's seat can be turned as standard. This makes it easier to get in and
out. The following actions apply here:
ADVICE FROM KEVIN A good rule of thumb for the adjustment of the
seating system is to sit without shoes on the duobike with the crank facing
away from you. With your heel on the pedal, you should barely be able to
extend your leg. From this position, you can adjust the seat to the position
you find most comfortable.