At the age of 66, I converted my bike to a tongsheng 500w with 48v 14ah battery. I wanted to still use my bike for exercise, not as an electric scooter, so no throttle! I recently did a 70 km ride on it, covering ascent of over 1200 metres. We have lots of hills in North Devon. The battery was still over half charged. I felt pretty tired but I covered roads that I wouldn't have attempted normally. Thanks for your informative videos.
BBS02 rider here..With minimal effort I can travel 30 miles on a 54.4v fully charged (48v battery) with 12.5ah. With my 58.8v (52v) battery I can travel over 80+ miles with 30ah. Never been able to test the full range as I get saddle sore. Great video Luke👍🏻
Great videos that have helped me choose and build 2 ebikes. One with rear hub drive and the tsdz2 mid drive. For me the clear winner is the Tongsheng. I can easily peddle alongside someone walking or ride in a group who do not have e assist. The rear hub drive wants to go a set speeds and that speed can dramatically change as one encounters a slight hill or down slope requiring constant selection of assist levels. I also dont like the drag feel when i am peddling slightly faster than the assist speed. But most importantly , the Tongsheng feels like i am riding a normal bike albeit I have the legs of a youngster. I like the feeling of a workout still but now I can do 20-30 miles not 4 miles and can go out every day ,not once a week. The Tongsheng is easy to bypass programmed speed limit should you feel the need. Once again , thanks for your effort in making these video, and oh, I envy you riding in Italy.
The equation is simple: If you want to go a certain distance at a particular speed with equivalent battery consumption, then the rider has to work at a certain rate. No motor is inherently more thrifty than another. You showed this - the Tongsheng used less battery, but you had to pedal harder. It is true that a cadence sensor motor is harder to ride economically than a torque sensor motor such as the Tongsheng, because a torque sensor prevents you from "ghost pedalling", whereas even the most careful rider of a motor like the BBS02B is going to be doing some light, or ghost, pedalling. Look at your figures - with the Tongsheng you cycled 7.69km per volt used up, with the Bafang only 4.26km per volt.
TSDZ2 with approx 1400km done since May 2022. Three times per week I do 500m drop in altitude downhill over 10km and then back up again, 52V 18Ah LiFePO4 15s3p and it takes about 5Ah to charge up again. I like pedalling. I like electrical assistance too.
I appreciate the experiment. We would all benefit greatly if more folks were working earnestly to properly compare the real world efficiencies of e-bikes and their powertrains. I know it's a little more difficult with the tools you have, but the best measure of energy used is to find Watt Hours used. The best way of determining that is to measure either the total Watt hours or Amp hours used (and multiply by your average or mean voltage). The way some of us do that is with the Cycle Analyst, but in my case, I have a Grin smart charger (Satiator) which expresses the total amp hours replaced when recharging to full. Both of those methods are more accurate than basing energy lost on voltage, which is both non-linear and also subject to sag. I'd interpret your outcome differently. I believe the Tongshen motor is never putting out as much current(and therefore power) as the Bafang when they are both set at maximum power setting. This is why you were struggling more with it. They may both be rated at 500W, but that is 500W nominal and not necessarily indicative of an average wattage of output over time. If you were to dial the Bafang back by one or two assistance settings, you'd probably experience similar performance and similar efficiency. I'd actually expect torque sensor motors to deliver less efficiency, and here's why. These motors prefer consistency and higher speeds to maintain optimum efficiency. With torque sensing, you are essentially varying the motor speed on every stroke, and this in turn varies the wattage constantly. With the cadence sensor motor, once it starts, it's much less subject to constant wattage variance, it still varies the output, especially as you reach maximum speed and as you take off from a start, but in theory, it's able to keep power stable and not suffer as much from variance in directing the motor to pull. The other issue with torque sensing is that as you grow tired during a long ride, the motor appears to tire too. Since it is acting as a torque multiplier, you no longer benefit from the motor's highest available output if you cannot provide high output yourself. For this reason, the best motor designs utilize torque and cadence sensors to both simulate bionic legs (torque sensing), but also maximize efficient, constant motor output at a reasonable steady rate of travel. Ideally such a system would have a "tired" mode, to allow minimum effort from the rider, while still providing the high output required for timely transportation. I believe use of a throttle is completely ruining your experiment's observations, as it's use is an indication that your input is not consistent, but you're introducing a whole new variable that you're not tracking in your experiment.
According to current graph displayed by ToolKit RC wattmeter the current on TSDZ2 fluctuates only at low cadence and high torque on the pedals, then it smooths out and keeps reducing as cadence rises. Agreed, about being tired, it only works best with fresh legs and battery, if you are tired then the TSDZ2 can somewhat start to bog down on hills slightly depending on many different factors. So there is a dilemma between saving the battery at the begging of the 80km route or saving legs for hills by using the motor more on false flats and flats.
Hi Luke & thank you for this comparison. I sell & install the exact same kits that you used for this test. I am a little confused why your legs were significantly more tired using the Tongsheng when it should have been amplifying your pedaling effort. One criteria that you never mentioned is what power level you operated both kits at. With the Tongsheng only able to chop up the available motor power into 4 equal chunks & the Bafang able to chop up the power into 9 chunks, this would affect your power consumption rates significantly unless you were riding both motors on full power all the time.
A throttle only range test would be a more accruate way to represent the range of the motors, as you noted the torque sensor requires more human input.
good stuff - I'm building a tsdz2 since I really only want the help on all the big hills around where we live or to extend some rides out. Going with a 52v build and the flashed version of software that lets it use a bafang 860 display.
@@LukeLorusso I installed the Emmebrusa firmware and configurator almost as soon as I set up my Tongsheng, best decision ever. I love the different modes and my motor was 250w from the factory which is not ideal! Its really good to dial in the 4 assist levels as well, next step for me will also be an 860c display.
I don't understand. Why not turn up the pedal assist level on the tongsheng if you're fatigued? Also there is a 750w versions that would give you even more access to power to prevent fatigue, no? I need a motor for commuting so I'm trying to understand why you're saying the torque sensor isn't best for mixed traffic.
I've got a 250 watt rear hub drive motor runs with a 10 amp hour 36v battery, easily does my 20 mile daily commute. Run with a throttle as the supplied Hall Effect sensor was rubbish.
Hello, the short answer is yes, it is also very common. The explanation is here: www.electrifybike.com/blogs/news/52v-vs-48v-batteries-which-one-is-better
As said in this other video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rgmsUVNLZXk.html after replacing the BBS02B from one bike to the other, I got the same range and max speed. This is because the difference in weight and style of those 2 bikes is negligible.
hey GM, thank you for your interest! unfortunately I never tried geared hub motors, but I expect similar wattage motors to be more or less equivalent in term of consumed energy. the 1500W GHM should be more energy hungry then a 500W mid-drive one, therefore I expect way more performance out of it. How much compared to a same wattage mid-drive kit? no idea unfortunately, but definately way more than a 500W one! with mid-drive motors you have a more balanced weight through the frame, that's why I like them
