General Maintenance / Electrical Troubleshooting

General Maintenance / Electrical Troubleshooting
General Maintenance / Electrical Troubleshooting &
Diagnostics Manual 2012
12.5 24V
16.0 24V
16.0 36V
© Copyright OSET Bikes Ltd 2012
Table of Contents
General Maintenance Introduction
Basic Weekly Maintenance Checks
Basic Monthly Maintenance Checks
Electrical Diagnostics Introduction
Symptom – No Power / Sudden Loss of Power
Symptom – Decreased Run Time
Symptom – Decreased Run Time – Brake Set-Up
Symptom – Decreased Run Time – Motor
Symptom – Battery not charging / accepting a charge
Symptom – Wont turn on / No lights on throttle
Symptom – Intermittent throttle response
Electronic component connection configuration
Wiring diagram
General Maintenance Checks
If you purchased your OSET Bike through one of our accredited UK dealerships then the bike will have been
checked and a Pre-Delivery-Inspection (PDI) should have been carried out.
A PDI from your local dealership will have included :
- Removal of all packaging & full build completion of the bike from part factory assembly .
- A check to determine all fixings and components are secure and safe for use.
- Fine adjustment of controls.
- A check to ensure batteries accept and hold a full charge.
- A check to ensure correct chain tension.
- A check to ensure nothing has been damaged or altered from factory settings during transit.
In some cases it may be that you purchased your OSET direct from us . In the event you were not located in
close proximity to an accredited OSET dealership . In this scenario we may have supplied direct, and as a result
you would have received your OSET in the original crate straight from the factory. OSET can not be held liable
for the completion of the build and stress that during assembly you follow the guidelines set out in the
accompanying user manual.
Every effort is made by the factory to ensure the highest standard of quality control is met, and furthermore the
PDI checks carried out by the dealership ensures your OSET is first ridden as our designers and factory
intended. However as with anything mechanised maintenance and care is necessary in order to keep your
OSET in its best condition. To do so we have compiled a list of tasks or jobs you may wish to carry out in order to
help you get the best out of your OSET.
Basic Weekly Checks
We at OSET believe our electric trials bikes are virtually maintenance free, and in terms of the electronic
components that is certainly the case. However , it is still a small wheeled motorcycle and as with all things
mechanised there are a few general maintenance items that you should consider, to get the best from your bike.
If you do not feel confidant to perform these checks yourself then your local OSET dealership may be able to
assist you, or alternatively you can call OSET Bikes Ltd on 0843 289 2890 for advice.
Here is a list of the minimum checks you should carry out on your OSET on a weekly basis. (Time = 10 mins)
- Check all components are secure, start at the front of the bike and work in a methodical manner checking the
tension on each bolt and fasteners, including handlebar clamp, stem / steerer, wheel nuts / skewers, brake calliper,
levers and controls, plastics, swing arm bushes, motor bolts.
- Check battery bag straps for signs of wear.
- Check tyre wear and tyre pressures **OSET recommend the following tyre pressures for trials use.
- 12.5 24V (Standard 12.5 x 2.4 Tyre) Rider age 3-5
8-10 PSI
- 16.0 24V/36V (OSET Kenda Nevis Tyres) Rider age 5-6
- 16.0 24V/36V (OSET Kenda Nevis Tyres) Rider age 7- 10
12 – 15 PSI
Basic Monthly Checks
Here is a list of checks to perform each month. (Total Time = 20 mins)
- Brake pad wear rates. Keep an eye on the amount of braking material on your brake pads (Depending on
the conditions the bike has been ridden in will determine how often pads would need replacing). Removing
the pads themselves is not necessary, however you will need to remove the calliper in order to inspect the
- Ensure the Brakes on your OSET are well adjusted. Please refer to page 16 - 18 of this document for further
- Ensure drive losses have been minimised, by this we mean any factor that could increase the resistance of
the wheels to turn. This could be anything from wheel bearings, to the chain line, chain tension, motor
bearings, poorly adjusted brakes. More information on how to check each of these items is present
throughout this document.
- Check your OSET’s brakes and controls are well adjusted to the needs of the rider. As your child grows, so
will his / hers ability and skill level change. These changes may influence your child’s ability to pull on the
brake levers . For example their strength may increase over time and the original lever reach and biting point
of the brake (I.e. when the brake pads contact the braking surface) may no longer be sufficient. Furthermore
the cable may have stretched resulting in the biting point of the brake disappearing towards the handlebar
resulting in little or no stopping power.
- While it is very unlikely that you will ever have to act on this, in the interest of rider safety, we feel with any
bike it is important to check the frame for signs of wear or fatigue that may be an occurrence of impact
during a crash. In this case report findings to OSET Bikes Ltd on 0843 289 2890.
Electrical diagnostics
This part of the document is designed to help the user identify any faults they may be facing with their
OSET Bike.
Simply look-up the symptom or fault you are experiencing from the left hand column and follow through the
component check order column utilising the notes column for guidance until you have solved your problem.
The next steps are then explained in the solution column. If you are still struggling or require further
assistance then please do not hesitate to give the technical department a call on 0843 289 2890. We are
always happy to help and certainly do not like the idea of bikes out there not working or performing how they
In exceptional cases, it may be necessary to send components or wiring looms or complete electrical systems
to us, in order to solve any problems. Repair and diagnostic work can be carried out by us at OSET HQ , we
endeavour to turn around items as quickly as possible. We charge £20 per hour for labour plus any parts
needed to fix the problem. However in most cases we can fix any electrical problem in under 30 mins. Please
call 0843 289 2890 for advice should you require this service. Alternatively one of our OSET dealer may be
able to carry out the work.
In most cases you won’t even require tools for most of the checks you will need to make in order to diagnose
a fault with your OSET, as your OSET has been designed with simplicity in mind.
Component Check
1. No
or a
Loss of
1.1. Potentiometer
(speed dial)
In most cases this is likely to be caused by a faulty potentiometer.
Locate the potentiometer positioned behind the rear splash
guard. Remove guard and plastic seat unit, and disconnect and
remove the batteries. You should now be able to follow the wires
from the potentiometer to the controller (silver box – attached to
top of chassis). There is a small black push fit connector
connecting the potentiometer to the controller. Disconnect this
and re-fit the batteries. Your OSET will run without the
potentiometer but you will lose the ability to regulate the top
1. Order a potentiometer. There
are two types of these. A mk22
was fitted to models circa 20072009. A mk47 was fitted to
models 2010-2012.
1.2. Connection
There are many connections all over your OSET and as with
anything electrical it is important that there is nothing that could
compromise the system. Simply isolate each connection &
disconnect. Inspect each one and check for evidence of ‘arcing’,
debris, loose wiring or anything obvious. Waggling wires and
connections as you go you may be able to assign your problem to
a specific connector or portion of wiring.
1. Replacement connecting blocks
are available if you would like to
create a factory repair to your
OSET. Alternatively it is perfectly
ok to use a standard spade
connector, or if you are competent
solder the connection back
together, ensuring the wire has
been reinsulated.
1.3. Relay
The relay is located directly underneath the seat unit. It is a small
black box which is simply a switch, which operates when you turn
the key of your OSET. A relay which is operating correctly should
make a noticeable clicking noise when the bike is turned on.
Absence of the ‘click’ will probably mean that your relay is faulty.
A relay that is not working will also mean you will have none of
the charge indicating lights showing on the throttle body.
1. Replace the relay. Please ensure
you have the year of manufacture
and model of your OSET to hand
before calling as this does
influence which relay you will
1.1 – The potentiometer on your OSET is located between the
key switch and charge port just above the battery tray. The
potentiometer can be adjusted from the rear with a flat blade
screwdriver through the access hole in the rear splash guard.
1.3 – The Relay pictured to the left ‘off the bike’ and above
located on a 12.5 24v. To remove simply undo the 4mm Allen
bolt securing it to the frame, disconnect the key switch at the
black connector and from the wiring harness via the larger
white connector.
Component Check Order
1. No Power
1.4. Fuse Holder / Wiring
or sudden
Loss of power
This is the wiring loom that links the batteries to the relay,
controller and charge port of your OSET. Firstly remove the
fuse from the harness (located beneath the battery cover)
and check the fit. If the fuse is particularly loose in the
holder, close up the connection with a small flat blade
screwdriver. If there is not a good connection here it could
cause ‘arcing’ and in some cases heat developing in the area,
This may mean that the wiring has been compromised. If
there is no pitting on the fuse there is probably no damage.
However there is a small diode in the harness which is
responsible for controlling the flow of current when charging
and heat can damage this.
1. If you feel that there
could be a problem with
this component then
please do give OSET UK a
call. A member of our
technical team will be
able to help you.
Replacement wiring
harnesses are available as
a ‘plug and play’
2. Decreased
Run Time
The LED battery indicator level is displayed on the throttle
body on the handlebar of the bike. At full power following a
charge all 4 lights should display red. If you see less than this
it is an indication that your batteries are either not producing
the required voltage or they are unable to accept a charge
from the OSET charger. There are a number of scenarios in
which this could occur and this is simply a case of isolating
one to your situation. It is possible to test the output of each
battery with a multimeter if you have access to one. Good
batteries will generate around 13v each. Batteries showing
only 12.1v, 12.2v or less will either mean they have not been
charged adequately, have a bad cell, or are simply old and are
past their best. Our sealed lead acid gel type batteries should
last for around 200-300 charge cycles or 18 months. After
this time they will still operate but will not be able to give the
same run time as when the OSET was new.
1. Purchase New
Batteries to restore the
level of run time.
2. Accept that the
batteries are old and past
their best.
2.1. Batteries. **Run Time is
difficult to quantify for electric
motorcycles as there are so
many factors, such as the
weight of the rider, type of
terrain, riding style etc that can
influence it. We approximate 1
hour to 1 ½ hours run time for
all our current OSET models.
However if you feel that your
batteries are not at this level
then check the following.
1.4 – Location of fuse. Check for damage to the fuse,
and the integrity of the associated loom (Wiring
2.1 – The Voltage output of the batteries can be
checked by means of a Multimeter. Measure each
battery individually by placing the electrodes of
the Multimeter across the terminals.
Check Order
2. Decreased Run
2.2. Chain Line,
tension & Drive
It is important to consider correct maintenance
of your OSET. For example, incorrect tension of
your OSET’s chain could result in energy losses.
A chain that is run too loose (apart from
coming off all the time) will cause ‘chain slap’ –
whereby the chain flails and creates more
resistance for the motor to overcome, which
subsequently requires more power and
eventually runs the batteries down. The
reverse of this – having the chain too tight, can
place an increased amount of tension on the
motor shaft and subsequently cause a drive
loss. Lastly if the front sprocket and rear
sprocket are not in good alignment with each
other then it will cause the chain to twist and
increase the friction levels, also causing a drive
loss. It may be that it is time to replace the
chain if you are unable to get a consistent level
of tension. Maybe the chain is now stretched
too far or the sprocket is warped or bent due
to an impact.
1. Check for correct chain
tension, there should be
around 1-2mm of
movement in the chain if
you were to squeeze the
chain just behind the front
sprocket with your finger
and thumb.
2. Check for correct chain
line, i.e. that the rear
sprocket is directly inline
with the front sprocket.
3. Replace chain.
2.2 – Correct chain line can be seen (above left). It is very important to ensure the rear wheel is located square in
the swing arm to enable the rear sprocket to run directly inline with the front sprocket. The tension of your chain
can be adjusted via the chain tugs located on the rear axle (above right). Tip – correct chain tension can be found
by locating your finger and thumb on the top and bottom of the chain just in front of the chain cover mounts. You
should be able to squeeze the chain together by 1-2mm. If your rear and or front sprocket is damaged or worn,
your chain is twisted or stretched then you will need to replace them.
Component Notes
Run Time
2.3. Brake
1. Cable Operated Brakes (16.0 & 12.5): Check the
cable can move freely within the cable outer, look
for any wear in the cable, debris or corrosion that
could cause it to snag. Ensure that the cable is well
lubricated. A cable oiler is a useful tool for this.
2. Hydraulic Brakes (20.0): Remove the brake pads
& ensure the slave pistons are able to return freely.
Clear any debris behind the brake pad &
surrounding the pistons and lubricate if necessary.
A lazy piston could cause the brake to rub.
2. Disc Brake Models (16.0): Ensure that the rotor
is central in the calliper, and that the rotor is
running straight and true.
3. Front V-Brake models (12.5): Ensure brake pads
are orientated so they are parallel to the rim, that
they will contact the rim only and not the tyre, and
importantly that the rim runs straight and true.
4. Rear Band Brake Models (2007 16.0 24v): Ensure
the brake shoe is free from debris and corrosion,
and that the ‘band’ mechanism itself is well
Ensure that both of the cable
operated disc/band or V-brake that
are fitted to your OSET are correctly
adjusted, as any unnecessary
contact between pad material and
rotor of brake shoe, will cause
friction which ultimately the motor
must overcome by drawing power
from the batteries more quickly.
2.3 – 12.5 24v Front V-Brake / rear band brake cable operated models. The V-Brake on your OSET can be adjusted first
by ensuring that the brake pads are correctly aligned to the braking surface on the rim, ensure that the pad will
contact the rim fully & square on, & that it will not touch the tyre. Tension the brake cable either by the barrel
adjuster on the brake lever or by pulling more cable through the lever arm. Lever reach adjustment will affect the
amount of cable being pulled through and therefore could result in the pads dragging - ensure you have 1-2mm gap
between the brake pad and the wheel rim on both sides.
2.3 (cont) – The Rear Band brake is
mounted on the swing arm. There
is a small amount of adjustment at
the end of the cable here, check
that the band itself is not dragging
on the braking surface, ensure that
the internals on the band brake are
not damaged and that the brake is
free from debris.
2.3 – Cable operated mechanical disc brakes - cable
tension adjustment can be made via the barrel
adjustment on the lever and at the calliper. Lever
reach adjustment can be seen above by using a
2.5mm Allen key. Again always ensure that before you
make any adjustment the wheel is sitting square in
the fork dropouts and that the quick release system is
firmly secured. Spin the wheel to check the disc is
running true.
Note if you have signs of uneven pad wear, i.e. you
can see areas of the disc that is not making contact
with the pad, then check the alignment of the calliper
ensure you have 1-2mm gap each side of the disc
2.3 – A Hydraulic Brake upgrade is available for all 16.0
models. The Tektro Auriga Comp has been modified by
OSET so that hose lengths are a correct fit. While the
brakes do come with full instructions, we have included
the basics here.
The basic calliper adjustment and alignment to the disc
rotor are the same as per the cable operated version as
mentioned earlier. Lever reach can be adjusted on the
front of the lever, while the biting point is adjusted with
a 2.5mm Allen key at the master cylinder.
Hydraulic disc brakes offer benefits to the rider in terms
of lowering the resistance of the brake lever to move
(ideal for little hands) and increasing stopping power.
Generally these brakes require less maintenance than
their cable operated counterparts as there is no cable
that needs lubricating and tensioning. Similarly the pads
return with more force due to the mechanics of this type
of system.
However, in the event of a damaged hose these brakes
may require a re-bleed to fill the system back up with
mineral oil, and to remove any air from the system. In
this scenario we would advise your local OSET dealership
to carry out the repair, unless you are proficient yourself.
Check Order
2. Decreased 2.4. Motor
Run Time
Bearings/shaft &
Drive Losses.
Remove the motor from the bike and inspect the
motor shaft and sprocket. You should be able to turn
the shaft freely with your hand. If you cannot , there
may be some debris that has worked its way into the
motor over time and is causing unnecessary
resistance. Secondly, check for wear in the motor
bearings by pushing the shaft in towards the motor
casing. You should not be able to do this. If there is
excessive play in these bearings it will cause the
chain to rub against the motor mount bracket on the
swing arm. The increased friction will cause the
motor to work harder for the same level of
performance and as a result will drain the batteries
more quickly than usual.
1. Replace Motor
Bearings** - we do not
recommend you tackle this
unless you have access to
the appropriate tools.
Please call us at OSET for
advice first.
2. Replace the Motor.
2.4 – Here the motor has been completely removed from the bike. To do this you must first disconnect from the
controller. Secondly, remove the rear wheel, and the lower rear shock mount. You will now be able to remove
the swing arm from the bike by removing the swing arm bushings (an 8mm Allen key is necessary). Lastly, split
the swing arm to free the motor by removing all 3 of the motor mount bolts. You will now be able to check the
motor bearings simply by assessing whether you have any ‘play’ or movement on the motor shaft. If you do, then
you will need to replace the motor bearings. In most cases we suggest a better solution is to replace the motor
Symptom Component
Check Order
3. Battery 3.1. Dead
It may be that there is no problem with the charger or
charging system on the bike but the batteries are no longer
in a fit enough state to accept a good charge. The output of
the batteries can be measured by the process described in
1. Check Battery output
level if below 12.1v it is
likely the batteries need
If you have access to a multimeter, then it is possible to
measure the voltage output of the charger by placing the
electrodes of the multimeter into the output lead of the
charger. MK1 & MK2 Chargers: For 36v models the correct
reading should be between 38-41v, for 24v models the
correct reading should be between 28-31v. MK3 Chargers
opperate slightly differently. When the charger is not under
load a 36v charger will elicit around 48v, and around 38v
during a charge. While a 24v charger will elicit around 42v
not under load and around 32 during a charge. If you are
not sure about performing this test then call us or we can
carry out this test at OSET HQ.
1. If the voltage output
from the charger is
dramatically outside of the
stated range, then call us at
OSET immediately.
3.3. Off Bike
If you have one of our Off Bike Charge Kits, then you will be
Charging Test. able to remove the batteries from your OSET and charge
through the kit. If the batteries will accept a charge in this
way then you can rule out any possibility of a wiring issue
with the bike.
1. Order Off Bike Charge Kit
from OSET.
3.2. Charger
3.2 – Place the electrodes from your multimeter into the top two holes on the charger to bike lead to get your
voltage output reading.
Check Order
3. Battery Not
3.4. Charging
MK1 (2007-2009) & MK2 Chargers (2010-2011): Put the bike on
charge, flick the switch at the wall and look at the LED on the
charger. This should be green when not plugged into the bike ; red
when you are charging the batteries and should trip to green after
around 4-5 hours indicating a full charge. If it does not do this then
you may not be getting any charge to the batteries or the batteries,
due to their condition, may be unable to accept an adequate
MK3 Chargers (2012): These chargers operate slightly differently.
1. plug the charger into the mains outlet – the light on the charger
will flash green and then turn to solid green. 2. plug the charger
lead into the charge port on the bike – the light will flash red
indicating the batteries are charging. 3. once the batteries are fully
charged – the light will turn to solid green. If it does not do this
then you may not be getting any charge to the batteries or the
batteries, due to their condition, may be unable to accept an
adequate charge.
1. Order a replacement Charger.
In this case it is advisable to talk
your symptoms through with a
member of the OSET technical
3.5. Charge
Check the condition of the charge port. As with all things electrical 1. Any damage to this will
it is important to have good contact at the connection. Look for any require a replacement Charge
signs of damage, debris or corrosion that could be causing a
problem. Remove the rear splash guard so you can inspect the
wiring at the rear of the charge port, this should have well soldered
connections insulated by a resin material with two small wires, one
of which connects at small black connector with the controller,
while the other connects in the same way to the wiring harness.
Check that both these connections are intact and that the wiring is
still well insulated.
3.5 - Here you see a charge port removed from the OSET. The charge port connects into the wiring harness.
Ensure that the wires look in good shape and that the back of the port is still well sealed with resin. It is a
very simple component and as a result there is little that could go wrong.
Check Order
3. Battery
3.6. Wiring
This is the component that is effectively the loom,
connecting from the battery terminals themselves right
through to the relay and controller. Current feeds from the
charge port into this and then onto the batteries. Anything
that could block the flow of current will result in the
batteries not charging. Check the fuse in the holder and
ensure the connection is tight, ensure also that the spade
connectors on the terminals create a secure fit with the
battery. Once all of this is checked and you have ruled out
all of the above, it is possible that the diode built into the
harness is no longer allowing current to flow from the
1. Order a new wiring
harness. Ensure you have
the year of manufacture of
your OSET to hand, as our
sales department will need
this to designate you the
correct replacement.
3.6 - This picture shows a wiring harness disconnected from the bike. To remove it you must disconnect from
the controller, relay, charge port, and the batteries.
Check Order
4. My OSET
4.1. Relay
won’t turn on?
No lights on
the LED
throttle display
The relay is the small black box mounted in the seat area of the
frame. It connects to the controller unit and the key switch of your
OSET and feeds in to the wiring harness. When turning the key
have a listen to the relay. In a relay that is operating correctly you
should be able to hear a noticeable ‘clicking’ noise, shortly
followed by the charge indicator lights on the throttle being
displayed. If there is an absence of this, it is likely that the relay
needs replacing. Another cause of the relay not activating would
be a faulty key switch. The two key connection wires (one from
the relay and one from the controller) can be shorted together –
creating an ‘on’ condition. If the relay now clicks, the key switch is
the problem. If it does not, it is likely the relay.
No Click from Relay? - Order a
New Relay – be sure to quote
the correct voltage for your
model. (It is important for this
component to specify the year
of manufacture, as the main
wires running to the vertical
and horizontal pin connector
are reversed on later models).
– **You are aiming for the Red
wire from the wire harness to
run into the red wire from the
Relay Clicking? - Order a new
key switch.
If you can hear the relay actuating as detailed above, then double
check all the connections running from the battery terminals,
through the wiring harness, fuse, and key switch. Check for any
debris and evidence of arcing.
1. Replace connections if needed.
All connector blocks are available
from OSET UK
4.3 Controller
Once the above avenues of enquiry have been looked into, it may
be that your OSET has developed a fault with the control unit. In
this case there is very little you can do as it is a sealed unit. There
is a small circuit board within, and if this has been damaged in
some way or has stopped functioning then the only solution is to
change it.
1. Replace Controller, again be sure
to quote the year of manufacturer
of your OSET.
4.3 – Your controller unit is located on the top tube of the frame. It connects directly with the throttle (via both 3
pin white connector & small 2 pin black connector), the motor, (large white connector Green & Blue wires), the
wire harness (large white connector red & black wires), the potentiometer (via small back two pin connector – x2
white wires), & one side of the key switch (via small two pin connector – small single back wire). Before assuming
the highly unlikely scenario of your controller not functioning, rule out connections problems first.
Check Order
5. Intermittent Throttle
response / LED Charge
Indicator Displayed / Power
in system but no drive at
the motor.
5.1 Throttle
The Throttle is a relatively simple
component and works by regulating the
power to the motor via the controller. In
some cases the throttle body can become
damaged through the bike being dropped
on its right hand side. While there may be
no evidence of damage from the outside,
there may be inside.
1. Check year of
manufacture of your OSET
before ordering a
replacement, check also
whether you will require a
white connector or black
connector to maintain
compatibility with your
5.1 – Here the throttle is removed from the
OSET. In 99.9% of cases faults with throttle will
be a direct result of the bike being dropped on
its right hand side. While there may be no
visible damage, the resistor in the throttle
body could have been damaged, resulting in
either an intermittent message to the
controller or no message at all.
Tip – A good little modification you can do on all OSET Bikes is to fit a pair of standard off-road motorcycle grips.
This can be done by using a sharp blade to cut down the seam of the standard grip. The grip can be peeled off and a
new grip fitted. In doing this you will now be able to fit a standard mountain bike bar end into the handlebar. Now in
the event of a crash or mishap the throttle body will be protected.
We understand that it can be quite difficult to see how everything goes together on the OSET. Here you can see all
the electrical components mentioned throughout this document all connected up correctly off the bike.
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