Advice needed for front hub conversion

[DrDoezel]

This will be my first conversion.
The bike I want to convert is a VSF Fahrradmanufaktur T900. The frame & fork are made of steel.

Front, rear or mid-drive:

• The bike has a rohloff in the rear, and I want to keep it. So, rear drive is not possible.
• It has an eccentric bottom bracket which makes it more difficult to make use of a mid-drive system. The eccentric bottom bracket will become useless and I have to find another system to keep the tension on the chain. Mid-drives seems also to be less reliable than hub drives.
  → A front hub motor was not my first choise, but it seems to be the best option with this bike.

Some background information:

• Desired max speed on level ground: 35kph
• Desired max range at cruising speed: 25km (I can charge the battery at work) or 50km.
• Wheel size of the bike I want to convert: 28”
• Brake type of motor wheel: Magura HS33 hydraulic rim brakes
• Rider weight: 85kg
• Terrain: Mostly flat, 2 bridges
• This bike is used daily to go to work. So, the most important thing is reliability! Budget is not so important, but I am looking for a good quality/price ratio.

In my country, the maximum speed of a pedelec is limited to 25kph. The law for high-speed pedelecs is not clear at the moment. Therefore, I want this bike to look like a normal pedelec to not attract the attention of the police.



I tried to build a system with the components of “https://bmsbattery.com”.

Motor:

• Q100H 36V350W Front Driving EBike Hub Motor
  My wheel diameter is 28” (=700) which has a circumference of 2220mm.
  260rpm → Max speed will be 260rpm*60min/h*2220/10^6km=34,6km/h.
  https://bmsbattery.com/ebike-kit/630-q100h-36v350w-front-driving-ebike-hub-motor-ebike-kit.html?search_query=q100h&results=5
  Are there better alternatives?

First option: Controller, Display & Battery:

• Controller: S06S 250W Torque Simulation Sine Wave Controller for 24Volts or 36Volts battery pack E-Bike System.
  I read that this controller has cheap Mosfets, and heats up quickly. Is this going to give problems with my setup? Are there better alternatives?
  https://bmsbattery.com/ebike-kit/546-s06s-250w-torque-simulation-sine-wave-controller-ebike-kit.html
• Display: S-LCD3 LCD Meter for S-Series Controlers ($29)
  It only fits S series controllers. It is not suitable for other controllers.
  https://bmsbattery.com/ebike-kit/670-s-lcd3-lcd-meter-for-s-series-controlers-ebike-kit.html?search_query=S-LCD3+LCD+Meter+for+S-Series+Controlers&results=3
• Battery: 36V12.5Ah Case-08 Bottle Battery Pack Without Controller [$196]
  Continuous discharge current: 18A → I think this is enough to provide the amperage required by the controller. This controller is rated at about 10amps.
  https://bmsbattery.com/ebike-battery/785-36v145ah-case-08-bottle-panasonic-battery-pack-battery.html?search_query=36V12.5Ah+Case-08+Bottle+Battery+Pack+Without+Controller&results=1

Second option: Controller, Display & Battery:

• Battery & controller: 36V10Ah Bottle-09 E-Bike Battery Pack with a 20A sine wave controller inside. [244$]
  Packing List:
  1. A 36V10Ah battery pack included a 20A sine wave controller and a EMC-180 charger.
  2. One S-LCD3, One Thumb throttle, A pair of Brake Grip, One PAS And Waterproof Easy Assemble Wires.
  Notice:
  1. Please download controller to motor waterproof wire diagram to make sure if it fits your motor.
  2. It only fits the motor with inner speed sensor. Please make sure your motor has inner speed sensor. It doesn't fit the external speed sensor.
  https://bmsbattery.com/ebike-battery/731-36v10ah-bottle-09-e-bike-battery-pack-battery.html?search_query=36V10Ah+Bottle-09+E-Bike+Battery+Pack&results=12

Brakes: I have Magura HS33 hydraulic brakes on my bike.

• Magura pressure switch for E-bike (2x22,27€)
  Are there alternatives? These pressure switches seems difficult to find...
  http://www.hibike.com/magura-pressure-switch-for-e-bike-for-all-rim-and-disc-brakes-schliesser-pd897c030ae9484fb91d5aea4278c224f

Padel assistant sensor:

• PAS--Pulse Padel Assistant Sensor With 12 PCS Magnets ($6,90)
  https://bmsbattery.com/ebike-parts/504-pas-pulse-padel-assistant-sensor-with-12-pcs-magnets-parts.html

Torque armes:

• A Pair of EBike Torque Arm (M12: $15)
  https://bmsbattery.com/ebike-parts/450-a-pair-of-ebike-torque-arm-parts.html#/301-size-m12

Speed sensor:

• King Meter Speed Sensor
  https://bmsbattery.com/ebike-kit/661-king-meter-speed-sensor-ebike-kit.html

Is this stuf going to work together? Should I buy extra cables or something?

 

[Drunkskunk]

I think you have a good basic setup. I've never tried to build a PAS system on purpose, so take my advice with a grain of salt.

That said, your controller is a bit undersized for the motor. It's a 350 motor, but only a 250w controller. It's better to be the other way around, and then limit the controller's output to match the motor. The S09P is a 500w controller, but that might be over kill for your needs.
Honestly, as cheap as they are, I might try the small one first, and replace it with the larger if it burns out.

BMSbattery is well known for their lackluster batteries. While the Adana "Cute" Q100H they sell is a well known high quality motor loved by almost everyone who's tried it, the batteries they sell are... marginal... The one you picked should function just fine with the motor being used as you intend. and a $200 battery that you can combine shipping costs on with the rest of the order might be worth trying.
Just know this is the weak point of your plan. If you do have trouble later, it's most likely going to be with the battery. A good battery is very expensive, however. It is probably worth trying the cheap one first.

Another point on batteries. You should always figure range in terms of the minimum you must have, rather than the maximum you can possibly get. For example, if you know your battery can go at least 25KM, then you don't ever need to worry about taking a 25KM trip. However, if you battery can only do up to 25KM, then conditions might not be in your favor on that 25KM trip. you might hit some unexpected detours, headwinds, hills, low tire pressure, or being chased angry pack of vicious poodles that causes you to use too much power and fall short of the maximum range, so you end up trying to pedal a heavier than normal bike the rest of the way

With no pedal assist, at 35kph you need around 22 watts of battery capacity per kilometer you need of range. Slowing down to 25kph drops that need to around 12 watts per KM. adding in pedal assist can drop that even further, but that amount can vary greatly depending on [strike] how lazy you are [/strike] how much effort you actually put in.

So in this case, your battery is good for about 25km at 25kph minimum. you may get further, and you will get further with pedaling, but you can rely on that 25km. If you want to cruise at 35km, you'll need to double the battery size.

 

[motomech]

Motor:
Q100H 36V350W Front Driving EBike Hub Motor
My wheel diameter is 28” (=700) which has a circumference of 2220mm.
260rpm → Max speed will be 260rpm*60min/h*2220/10^6km=34,6km/h.
https://bmsbattery.com/ebike-kit/630-q1 ... &results=5
Are there better alternatives?

You mean faster?
Actually, that combo will top out at 32 Kph, fast enough for a bike without suspension nor wide wheels and tires.
A Q100H 201 @ 48 V would have the same top speed and climb better.

Controller: S06S 250W Torque Simulation Sine Wave Controller for 24Volts or 36Volts battery pack E-Bike System.
I read that this controller has cheap Mosfets, and heats up quickly. Is this going to give problems with my setup? Are there better alternatives?

Generally, when there is over-heating w/ a controller, it is because of a poor controller/motor match.

Battery: 36V12.5Ah Case-08 Bottle Battery Pack Without Controller [$196]
Continuous discharge current: 18A → I think this is enough to provide the amperage required by the controller. This controller is rated at about 10amps

I use Lipo, but the guys over @ Pedelecs UK recommend using the Panasonic cells, a more reliable battery.

Battery & controller: 36V10Ah Bottle-09 E-Bike Battery Pack with a 20A sine wave controller inside. [244$]
Packing List:
1. A 36V10Ah battery pack included a 20A sine wave controller and a EMC-180 charger.

My LIpo has an odd Voltage that sine wave controllers do not like, but once again, the guys across the pond like the intergrated controller, 20 Amps and a "H" Cute are a good match.

2. It only fits the motor with inner speed sensor. Please make sure your motor has inner speed sensor. It doesn't fit the external speed sensor.

All the new Q100s have the speed sensor, it's the white wire.

Brakes: I have Magura HS33 hydraulic brakes on my bike.
Magura pressure switch for E-bike (2x22,27€)
Are there alternatives? These pressure switches seems difficult to find...

Yes, you will have to fab. a reed switch. Try searching the posts of D8veh using key word Ebrake.

Speed sensor:
King Meter Speed Sensor

Pretty sure it's the other speed sensor. The King unit is for a King meter.

I like the left-side half-twist gthrottle. Since you will no longer shift the frt. gears, there will extra room there.

Order the spoke wrench.