The 2 Major Problems of Mid Drive eBikes that no one talks about

The bad clunk you’re experiencing is the result of using a low end cassette. Higher end ones will have nearly no play in them. When your riding a mid using pedal assist (not throttle) you should already be engaging the pawls before the torq of the motor kicks in, I could definitely see the issue if one was using just the throttle. I have not experienced the issues you are talking about with having to pedal at extreme cadences to keep up with my mid drives, but I haven’t ridden the diy mid drives. Mid drives I think are better suited for pedal assist, not throttle driven. They’re also better balanced for mountain bikers and take advantage of the gearing in the drivetrain to supply more low end torque when needed. Hub motors are extremely smooth in their power delivery. Each have their pluses and minuses.

What I did with my ebike (chinese) with a built-in mid-drive is - I went into the settings menu and set the smoothest enabling PAS setting. So that when I start pedaling, the motor would increase it's torque gradually. That way there's no hitting the freewheel internally by the motor. My legs initiate a smooth hit on the freewheel as it's suppose to be naturally, and by that time the motor catches up with me and starts doing it's job. It's a 1/2 second action, but it's real practical for me as a rider and healthy for the bike's freewheel.

I wouldn't recommend using freewheels with mid drive conversions. Your problem isn't from a too powerful motor, it's from using too low quality of a rear hub. You should be using a proper cassette hub instead of a freewheel hub. Freewheel hubs were only designed for bio power. Major differences in quality between the two components. This is coming from a bike mechanic.

I have never had any cassette/hub problems with my Bosch mid drive after 5 years of daily riding. I like the mid drive flexibility to run 2 different sets of wheels with different gearing on each. I run 26x4" for off road, sand, snow and 27.5x3" for commuting. It's very easy to swap wheels and fix flats on a mid drive.

Higher end wheel with more pawls will fix the clunky issue as well as smooth out the power delivery. My 2 cents. 👍

I have a Maxon hub motor from Switzerland for many years now with zero problems and zero maintenance. Friends with mid-drive motors, even expensive ebikes like Specialized, seem to have a lot more problems. Another benefit of a hub motor is a lot less wear on the drive train. With a hub motor only your power is transmitted to the rear wheel, while with a mid-drive motor, your power in addition to motor power is transmitted via the drive train.

First thing I did on my DIY build, with the same CyC X1 Stealth mid-drive motor, was to upgrade my drivetrain to a Box Components Box 2 P9 X-Wide Single Shift E-Bike Groupset. Absolutely love the combination. Feels like it will climb a wall. Eats the mountains here in BC for breakfast. Throw in a 21Ah/52V battery from Electrifybike and I am good to go for long rides. Best thing about the rear cassette from Box is the ability to purchase the first 4 gears for $20. They are the ones to wear out the fastest since I am using those the most by far. You can switch 1 out or any combination up to 4 gears. I have over 3,500 km on it with the only problem being 4 broken spokes so far. Zero flats because I upgraded my tires to Continental Ride Tour Replacement - extra puncture protection, E-Bike rated tires. I just got the portable/folding 200watt solar panel from Electrifybike. It puts out up to 4 amps, depending on sunshine, and will allow me to go further, much further into the mountains. It comes with a very compact solar charge controller. I also got a spare battery mount and a very lightweight 500 watt inverter from the guys in Utah so I can take the battery off the bike and connect it to the inverter to charge my drone, phone, or laptop and do my video editing in the middle of nowhere. All fits neatly in one of my panniers with room to spare. Love the freedom. Money I have saved in gas alone has almost paid for the bike build. By the way I purchased a used 2012 Brodie Bandit hard tail gravel bike in excellent condition on Facebook Marketplace for only $220 US. That was what gave me the extra money to go with the Stealth and the larger battery.

Thank you for your hypothesis and your description is second to none. Keep up the great work. You always bring valuable information to the table.

Very interesting video, as I'm about to build a Bafang mid drive bike. Sorry I haven't read all the comments. the play in the hub you talk about is the time it takes the pawl/tooth inside the hub to go from 1 point of engagement to the other. Typically even on expensive hubs there are only 36 points of engagement through a complete revolution of the wheel/360 degrees, meaning there is 10 degrees of free play before the hub bites. I don't know about your particular mid drives but the Bafang's motor on pedal assist mode requires the rider to pedal half a turn before the motor engages. Meaning the torque from your legs takes up that free play in the hub before the motor kicks in, saving wear on the freehub. However in throttle only mode all the motor's torque is transferred straight to the hub and once the free play is taken up you'll likely hear a clunk as the pawl engages, particularly from a stand still but also while you're moving. If you can reprogram the motor to reduce the initial current this will help. Also bike hubs weren't designed for 1000 watt motors so if this free play and early wear on the hub is a problem then factor into your build a 100+ points of engagement hub like the Halo Superdrive with 120 points of engagement for less than $200.

I would think solving the gear ratio problem with a larger front chainring could also help with the excessive torque on the freewheel, by increasing the leverage at the pedals. Freewheel are cheap and are easily messed up by a powerful rider on a regular bike so I definitely think it would resolve it for sure. I think mid-drive with an actual modern mountain bike rear hub could solve that as many of them have much better engagement. And are definitely a lot stronger then any freewheel

Just getting into ebikes with first build on 48v 1500w hub drive and lipos. 40mph seems fast enough! Enjoyed this! Subbed!

one of your finest video...very much liked that you went into details and although i have a bbs02 and think mid drive is the way to go...the points you discussed specially the stability of the motors and the pedal/motor ratio are very relevant.

Nice video, over here in the UK, I have fitted a front wheel electric motor hub drive , limited by UK law to only 250Watts power! I fitted it to my Marin full mountain bike with a Shimano 11 speed internal rear hub , instead of derailleur type sprockets! Although the front wheel hub motor is only 250 Watts, I have the benefit of a two wheel drive bicycle. Also I change can change gears to " help the motor out" on steep hills! An additional advantage of a front wheel hub motor drive is, that if my chain comes off, or breaks, I can still drive home using the front wheel on its 's own! A further advantage of this system, is that when off road, or in very muddy roads, I have twice as much traction with both wheels being powered! But being able to independently change gears to what the motor is doing, is very useful, and I can match the required effort of my legs, to the motor requirement to get up the steep hills in my area! Remember, at the end of a day, its still only a bicycle, and I ride it to get my daily cardio, so having a more powerful motor defeats the object! If I want to go fast or not pedal at all, I have my BMW R Nine T Scrambler motor bike, with 1200cc and 115 HP! if you get the point! Nice video ! take care on the roads over there!

Recently upgraded my Cannondale hybrid road bike with a Bafang BBS02, which has a cadence sensor. Although it is not as smooth as a torque sensor bike I tried, I am still very happy with it. I left throttle off as I wanted to pedal when moving, and the motor addition is a real game changer for my aging knees when facing hills and headwinds - I live near the Rockies. And I haven't really found that I need to pedal overly fast to cruise with the motor running.

My dad bought me a dirt bike converted to pedals and now I’m trying to convert it back to a motor, electric of course. This video gave me relief, now knowing it’s a good thing my back wheel gear is bolted on. Also love the videos :)

I live in the Appalachians, I go up large mountains all the time. A mid Drive motor is absolutely essential if you're going to be going up steep hills. A 750w rear Hub drive compared to my bafang bbs02 750 watt mid Drive.. is no comparison at all! The only way the Hub Drive motor makes sense is if you don't have any major Hills to climb. Because unlike the mid drive, you can't re-gear the motor using the drivetrain. There's one Hill in particular here that has a 34% grade and my mid Drive goes right up at 14mph in elec gear 9 mech gear 2. I can do 39 mph on the flat in elec gear 9 and mech gear 8. I have it set up that the motor barely assist me and just makes it a lil easier to pedal in elec 1 and 2. You can program the mid drive to your liking. Each gear is individually programmable. You won't be able to do that wide a variety of riding with a single geared hub motor. Well, you Could but you'd have to run say a 2000w or 3000w motor and say, double the battery size to compensate. Even then, it wouldn't be as good. The largest problem with mid-drives is people that don't know what they're doing try to mount them to a low quality bicycle. It can wear out the driveline components on a cheap bike. If you need to ASK someone if the bike that you have is "too cheap" for a mid drive motorization.. then you don't know enough about bikes to build a mid Drive to begin with!

I found that Tong sheng Tsdz2 mid drive 750watt is great, installed on a duel suspension MTB done 3000 ks I replaced the blue gear(32 aus dollars) at 2000ks to find little wear. Also the drive chain doesn't seem to stretch as much as you'd expect. The pedal assist is smooth no spinning. I had the display in recent times cut out. I suspect it maybe condensation. (East coast Australia has had continuous rain for months!)But if I reboot it's all good. I also found that I can pedal just fine with unit off. I mainly ride in "Tour" mode which is 2nd egear. On hills if tired I put up to "Speed" 3rd egear flys up the hill super smooth, and I still have Turbo 4th egear. I have 52volt 13amhr triangle battery that's made to fit my medium size frame. All the weight is where you want it! Centre of gravity is between your legs.The first time I rode on MTB Trails it felt natural just faster and easier. Range in 2nd gear 140ks! The motor and battery cost 1100 au dollars. Bought from Alibaba in 2018.

A good free hub and cassette helps a lot. A cheap freewheel will eventually come apart with a moderately powerful mid drive. Turning down your start current(soft start) helps as well

At 69 I'm still peddling the bike myself, and the 1.1HP peak of me is long gone in the past. Just got a frame today to try adding electric assist to, so your posting is both timely and very much appreciated. Be safe our there!

I have ridden a few thousand kilometers on my 750 watt Tongshen Tsdz2 mid drive. The issues you mention I would not have thought of. The only issue I have with the mid drive is breaking a chain - because you have no way to pedal the bike like with a hub motor. The Tsdz2 is a very smooth motor and has four levels of PAS. It is important to shift to lower gears on startup and to choose the best PAS option. I have an 800 watt battery and there is no hill that presents a problem. The MTB drive train is not designed for propulsion that is the equivalent of the strength of three persons. If the power is abused the drive train will wear out prematurely. If I use the second level of PAS I can get 60 miles out of the battery for about 10 cents of electricity. It was a mistake to have such a heavy 48 volt battery but I never run out of power. I own both the Tsdz2 mid drive and two 300 watt hub drive ebikes and find both drive systems have merit. The less powerful hub motors do not tax the sprockets and chain like the mid drive. There is a great risk of addiction to 750 or 1000 watts and the speed that comes with that energy.