"Modern" mid-drive motors with special frames vs. 68/73mm bolt on mid-drives

richj8990

100 W
Joined
Jan 21, 2020
Messages
277
I have the money for a newer mid-drive motor and frame. It's not that I don't. It's really a question of how much better...if they are significantly better at all than the Bafang (or Tongsheng, CYC, etc.) BSA bottom bracket slide-through then bolt-on motors.

Example: I already have two candidate frames for a Bafang 750W BBS02 bolt-on but neither are great. One is carbon, one is a relatively heavy QR frame with a 27.2mm seat tube. On EBay there are aluminum hardtail frames that look pretty decent, around $550 including shipping from China, and they usually have either 30.9 or 31.6mm seat tubes for a long dropper post, tapered head tubes and 12x142 thru-axles in back. That way I'd have 3 bikes (two would still be acoustic) all with 15x100mm front axles and 12x142 rear. I'd ditch the QR frame mentioned above later. That would be a lot more convenient for switching wheelsets since right now I have 3 front and 4 rear 27.5 wheels that are either 100mm or 142mm axled. The BBS02 motor is around $500; I already have a Hailong II 850 Wh battery. So bascially around $1050 total for the frame and motor build, not including other parts like the fork, drivetrain, brakes, etc. Some of which I can cannabalize from at least one of the other bikes in the garage, like the QR one.

Compare that with building on a current top-end mid-drive motor and specific frame. If you use the example of Shimano's M600-800 series, many of those motors are around $2000 MSRP by themselves, just for the motor! And even a hardtail frame that fits that motor is at least $600 if not $1000 including shipping. Full-suspension, if you care to know, is usually $1600 and up. Even if I got a good deal on a contemporary mid-drive motor and acceptor frame, that's at least $2000 --- twice as much as the BBS02 and compatible frame.

Are the new mid-drive motors 2-3 times as better if you are going to pay 2-3x as much money for the motor and acceptor frame? Yes the BBS02 may weigh a few lbs more, but the standard torque on it is 120 Nm, that's not bad at all for a supposedly 'outdated' motor. What's so special about the newer mid-drive motors? Smoother power delivery? Run cooler? PAS better? Longer lasting? This is of course for offroading most of the time, steep climbs.

Opinions please, thank you.
 
Hi, i can give a bit of my own experience, i have a diy bbshd 26" with a 48v 17ah battery, great motor pulls like a maniac and go into speeds of 50kmh or more, great fun bike but even with that battery range is low due to power of the motor, then i have a winora radius tour, a german made mid drive bike with a yamaha pw motor, its a little fun bike that demands a diffrent kind of riding, the bafang has a 1000w (nominal power, it does bursts up to 1700w) and a throttle which is very useful to start riding after red lights etc, it rides as a moped as the pas is cadence sensor and as soon as you start peddleing the power given by the motor is fully available and according to the level selected (1-5 or 1-9 power levels, defined is settings) the winora with her 250w torque sensor pas will provide you power as strong as you pedal, pedal light and the motor power output is none, pedal harder and the motor output is higher, the bafang is like a electric moped the yamaha is more like a normal bike. Which one i like more? i like them both, i love the bafang power and open customization, i made my own battery and i can program the bafang controller, the winora is a great sophisticated bike, excellent build quality, since its a 20' its nimble and very agile in the city, you can twist the handlebar and fold the pedals and grab the bike like a little handbag and carry it to a train or bus or inside house, BUT i really hate the closed platform of the yamaha system, you can only use proprietary batteries since the BMS communicates with the motor controller via a serial connection, if you plug a 3rd party battery it wont work, and the controller is closed, you cannot customize anything, this for me is the downsize of that bike, and i'm currently thinking to open the motor to take the oem controller and use a cycle analyst and phaserunner instead, not only i will have full customization of controller parameter but i will also be able to use my own battery (increase the oem 400ah to a 600 to 800ah battery, or even a 48v instead of 36) but i will also be able to add a throttle wich i miss so much when riding the winora
 
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