Mid Drive
is a mid-drive motor system the right fit for you ?
Mid-drive conversions are more challenging to install than Hub drives . They require more technical know-how & skill.
Mid drive motor systems are installed and integrated with a Bikes Drive train “Crank” at the lowest-to-gravity point on a bike.
[ Hub drive conversions are a lot easier than a mid drive because the wheel is already built into the rim . ]
Depending on the Model and Specs of the bike you have , there is a good chance that with a Mid drive conversion ( even if you are an engineer or very technical ), you may still need further assistance from a professional bike technician in your community, town or city. Please do your homework.
While there are excellent advantages to mid drive e-bikes , It depends on your bike and your preferences.
pluses of a Mid drive conversion:
Even-weight distribution.
Torque output is high: Mid drive motor torque is double than hub drive systems for the same wattage. For example : 500w mid drive motor Torque is 100nM ; 500w hub drive is 55nM.
As a result of the higher level of torque output , the mid drive suits a person that wants to ride super steep terrain and/or who weighs 100kg or carries over 100kg of weight and who plan to ride off-road trails.
potential negatives of a mid drive conversion:
More Challenging to fit to a bike than a hub drive.
If the chain brakes the motor cannot drive the chain ( Hub drive is in the wheel with the ability to drive the wheel directly without a chain).
Less gears ( disadvantage if you ever ride the bike non-electric ) . Keep in mind that this is not a disadvantage if your bike already has a single chain wheel cog front derailleur.
be sure to get the right system for your bike and riding preferences.
Mid drive motors replace the front cogs of your bike as a single cog. Say goodbye to your current Drive train.
If you like using all the gears on your bike then reducing this to a single chain ring may not be ideal for you. For example : if you are planning to sometimes ride non-electric then having those extra gears will be useful on super steep hills especially that the bike is heavier.
If you plan to ride electric most or all of the time then there is really no need for the extra gearing.
check your bike specs :
bb ( crank set).
FRAME.
Mechanical Specs.
Weight.
HEALTH.
Terrain.
power and speed.
#1 your bikes bb (crank set)
Your BB type and size will tell you if an adaptor is required.
What is the SIZE of the BB on your bike ?
BB stands for ‘bottom bracket’. It is the frame tube where your bike’s crank is fitted.
What is the TYPE of BB on your Bike?
A bottom bracket (BB) is contained inside the part of the frame called a bottom bracket shell. There are two main BB systems on bikes: THREADED bottom brackets that have a thread in the BB shell . PRESS FIT bottom brackets do not have any thread and are pressed-in to the bottom bracket shell.
68MM BB is the most common size. It is also referred to as BSA or British standard bottom bracket. It is a threaded BB which most mid drive motor systems fit without any requiring any adaptors.
68mm (road)
73mm (mountain)
83mm (Downhill)
100MM (Fat Bike)
66~100MM Press-Fit BB’s need a special adaptor in order for a mid drive to be fitted.
68mm (Road)
73mm (Mountain)
83mm (Downhill)
100MM (Fat Bike)
Other BB Types: 61~120mm
There are several other types of BB’s: Trek BB90; Trek BB 95; Specialized OBB Alloy / Carbon, Cannondale BB30A; Cannondale PF30A;Calnago thread ; Italian ; Truvaitiv and others.
Which BB type do you have?
GREEN COLOUR:
NO ADAPTORS REQUIRED.
BLUE COLOUR:
MID DRIVE PRESS FIT BB ADAPTOR.
SPACERS (2mm,3mm,5mm) .
MOTOR STABILIZATION BAR.
REQUIRES EXTENSIVE CUSTOMIZATION.
WHAT YOU WILL NEED IF YOUR BB IS american :
USA - EU ADAPTOR
WHAT YOU may need to help with chain alignment :
FRONT DERAILLEUR CHAIN GUIDE
*Chain Alignment is of key importance and focus when fitting a mid drive*
The mid motor cog needs to align properly with your bike’s rear gear cassette. Synergy between the front and rear cogs is essential to avoid chain drops. Tweak the motor installation with spacers for improving chain alignment .
Smooth integration between motor and your current gearing is the goal.
#2 frame
Frame considerations
What is the size of the triangular area of your bike ( the area between your top tube , down tube and seat tube) ? The most likely and ideal fitting position for the battery is on the Down tube.
As Illustrated in the image on the right.
BATTERY MAY BE INSTALLED ON DOWNTUBE EXTERIOR IF THE SPACE IS ENOUGH BETWEEN WHEEL AND BATTERY.
THE SPACE INSIDE THE FRAME WILL TELL YOU WHICH BATTERY SIZE COULD BE INSTALLED.
LARGE OPEN FRAMES HAVE SPACE FOR ALMOST ANY SIZE FRAME-FITTING BATTERY.
#3 mechanical specs
THRU-AXLE VS QUICK RELEASE (QR) skewer AXLE
If your bike is thru-axle at the rear then going mid drive is your obvious choice.
A hub motor cannot be installed on a rear thru-axle bike.
However if your bike is QR ( quick release skewer ) at the rear , then you have both options hub and mid drive available to you.
TYPE OF TERRAIN
Do you intend riding heavy off road single-track type terrain?
Do you intend carrying a heavier weight of over 100kg?
Will you be riding up some super steep hills ?
If you replied YES to 2/3 questions , then a mid drive is likely your best choice.
Keep in mind that not all bikes were structurally made for heavy off-road so be sure to check how durable the frame and components are.
Now you need to look at the specs on your bike to see what kind of riding it was originally made for so that the system installed integrates with it in the best possible way for optimal performance.
GEARS
Your bike may have 2-3 front cogs working in union with a rear 8,9 or 10 speed gear cassette. If you prefer more gears then you may want to look in the direction of a rear hub conversion system. That way , your front derailleur and chain wheel systems remains 100% the same. Having these extra gears will only really be helpful if you want to power off your electric assistance now and again are ride the bike non-electric .
TYPES OF BRAKES
For Mid drive conversions, ideally your bike has Hydraulic or at a minimum a very good quality Mechanical disc brakes such as Tektro. As a general rule of thumb - The better the quality of brakes you have the bigger the motor you may consider. For V-brake bikes we recommend hub motor conversions or max 250w mid drives . Consider upgrading your brakes if you want to put a bigger motor on.
JOCKEy / REAR DERAILLEUR
Entry level jockeys suggest smaller mid drive or preferably hub systems. Consider upgrading your Group set if you want to put a bigger motor and bigger sprocket on.
CHAIN AND REAR GEAR CASSETTE
The quality of your cassette and chain is super important to performance . Be sure to check the condition it is in before going ahead with any conversion. If they are worn and need replacing it is best to do that before starting your conversion. Keep in mind that your current chain may not be long enough to fit the new mid drive conversions. This is often the case therefore replacing with a new chain is highly recommended.
REAR AND FRONT HUBS
Make sure that your front and rear hubs are in good condition and not in need of replacing or replaced bearings. If you have air shocks on the front make sure they are working nicely and pumped up pressure relative to your weight. There will be increased torque on your bike and making sure your bike has been checked and well serviced prior to doing the conversion.
RIMS , SPOKES AND TYrES
Mid drive motors are torquey and will get you going on the steepest and most challenging of terrain. You want to be sure that the rest of your components are up to standard. Please make sure these have been checked before taking off on your e-biking adventures.
GIANT ANTHEM FULL SUS 750W MID DRIVE CONVERSION
PLATINUM BREEZE 350W MID DRIVE CONVERSION
SILVERBACK FULL SUS 1000W MID DRIVE CONVERSION
#4 wEIGHT
Your weight plays an important role in deciding on which motor power wattage output is best for your conversion. Your weight plays an equally important role in helping you understand which battery will fulfil your desired range ie: distance in km per ride that you’d like to achieve.
We recommend that you get a motor that is either just right for your weight or bigger. Having more power and being able to reduce it at your fingertips is better than having a motor that is slightly under-powered for your weight. Also consider getting just the right motor size for your weight because as you get fitter on an electric bike, you will start to use lower levels of PAS ( pedal assist). This way you will need less and less power as you get fitter one ride at a time.
Below is a * Mid Drive Guideline Chart.
#5 health
For some people retaining a steady heart rate level is life-saving or detrimentally important to their health during exercise.
Electric pedal assist helps people maintain a steady level of power no matter how much the gradient of the terrain changes.
With PAS at your fingertips you simply increase and decrease the level of power when needed without having to stop to change anything.
if you do have any sort of problem breathing or need to alleviate pressure on your knees , hips or shoulders during riding, we suggest getting motor size that is slightly more powerful than your weight category.
Below is a * Mid Drive Guideline Chart.
#6 terrain
Steepness and Roughness of terrain play a big role in pointing you in the direction of the size mid drive and battery that would better suit you. If you plan to ride a lot up some seriously steep and rough terrain , it is going to need a slightly bigger motor and battery size than your weight category.
Choose one power level up if you think this will be the type of riding you will be mainly doing so that you always have that extra bit of power when you most need it.
Below is a * Mid Drive Guideline Chart.
#7 power and speed.
Mid drive Motor systems are super torquey especially when you consider the size of the motor in relation to the power output. Electric bikes are made for exercising and while power and speed are not the main focus, it is important to choose a motor that provides you with enough oomf to choose whatever level of assistance or non-assistance you want at any given moment.
It’s simple , if you want just the right amount of power and speed then choose the motor size that suits your weight.
If for whatever reason you want more then choose a bigger motor.
*MID DRIVE GUIDELINE CHART
* Please Keep in mind that Weight is a guideline. Other factors should be considered :
Example #1 : You may weigh only 60-70 kg, however the terrain you intend riding on is super steep and/or heavy off-road single tracks . Under these conditions it’d then be better to go for a slightly bigger motor.
Example #2 : For Health / Medical reasons , it is imperative that you keep your heart at a steady rate.