Do I Need a E-Brake?

I have several questions regarding my ebike build.

I bought a 500w Bafang motor and I'm mounting it on the front wheel. I'm not using PAS, only the throttle. I plan on using the throttle as one would use Nitrous on a car. Meaning, if I'm going up a hill, or if the wind is blowing right in my face and I'm going 1mph on a flat surface.

In this case, do I even need the ebrake that came with the kit?

Also, how exactly does the ebrake work? What I mean is, if I do want to install it (as a safety feature in case the motor short circuits or something and gives me 100% power) can I just mount it anywhere without hooking up the brake line? If I just pull on the ebrake lever without actually putting in the brake cable in there does it still work?

I am including a photo of my bike, you can see that I can't actually replace the stock brake lever with the motor kit ebrake lever.

BTW, the Bafang kit came with the thumb controller that doesn't have quick disconnect, meaning you have to unhook everything on the bars to mount it. I ended up having to spend $20 on a quick release one which was a bit annoying. They really should include a quick release mount.

BatteryMan said:

In this case, do I even need the ebrake that came with the kit?

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Nope, just leave them off.

Correct me if I am wrong, you have the throttle and PAS on the Bafang mid drive so you do not really need brake sensors, but I would fit them just in case you hit the throttle by accident when stationary or roll on the pedals enough for the drive to kick in, I have been caught out by the 500w Bafang rear hub drive when I was standing next the the bike and caught the throttle lever, luckily I managed to pull the brakes up as I had sensors filled. I do use the Tongsheng mid drives as will and have always fitted brake sensors due to the torque sensing system.
The brake sensors via the controller only cut the power feeding the motor and nothing else, release the brakes the motor powers up again.

dgc said:

Correct me if I am wrong, you have the throttle and PAS on the Bafang mid drive

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it’s a throttle only front hub setup.

The ebike brake cutouts are essentially just switches (there are some higher end versions that provide a graduated or ramped voltage cutout like a throttle for controlling regen capabilities but that's not what we're talking about here). So you can easily wire in a simple switch to provide the same type of safety cutoff.

I don't use brake cutoffs on my two ebikes that have similar power hub motors, but my controller/display setup is the Grin BaseRunner/Cycle Analyst and it came with a simple digitial control switch that includes a nice little easy to hit red switch that provides the same emergency cutoff ... however I've never had to use it.

Nice road bike setup, you'll love the addition of the motor. I think you'll find yourself using the throttle like a PAS control - that is using partial throttle settings for more than just the extreme situations. Power is addictive and I'll bet that at some point in the future you'll likely add the PAS (or torque sensor) capability to your bike.

Yes, I run PAS and throttle on my Giant Trance as there is momentary delay when pulling away using PAS only so I just touch the throttle momentarily. Old picture it now has air forks, throttle and frame mounted controller housing. Still to have another look at the controller setup to see if I can improve the PAS pickup. Went rear hub as frame would not take a mid-drive.

Mclewis1 said:

Nice road bike setup, you'll love the addition of the motor. I think you'll find yourself using the throttle like a PAS control - that is using partial throttle settings for more than just the extreme situations. Power is addictive and I'll bet that at some point in the future you'll likely add the PAS (or torque sensor) capability to your bike.

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Thanks.

I bought a small 4.5 pound 48V 10AH battery and I'm going to put it inside the frame bag along with the controller. I'm a huge fan of front wheel motors, it just feels the most natural to me especially when not even installing PAS and using the throttle as needed.

What I like to do is set the LCD controller to just 3 speeds.

0 - motor off
1 - 7 mph
2 - 15 mph
3 - no limit

I tried several different rear hub ebikes at local bike shops but they don't feel natural to me at all and when pedaling it feels like the motor is doing all the work.

I also have an ebike cargo bike that I build, also using the same Bafang 500w motor and a 52V 13AH battery.

(stock photo)

I chose a 52V battery on the cargo bike because the fork is so beefy, on the road bike I'm going with a 42V because even though the forks are steel they aren't as beefy as the cargo ones.

Sudden acceleration happens on ebikes. There's the human error situation where they bump the throttle at a bad time. There's also the electrical failure, which is not that uncommon. I've seen the latter several times.

As a result, I'll take the tradeoff of the extra wiring on my bike for brake switches as a safety measure.

docw009 said:

Sudden acceleration happens on ebikes. There's the human error situation where they bump the throttle at a bad time. There's also the electrical failure, which is not that uncommon. I've seen the latter several times.

As a result, I'll take the tradeoff of the extra wiring on my bike for brake switches as a safety measure.

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As for myself, I only put features on my e-bikes that help them work, nothing whose job it is to keep them from working.

I'm picky about lever pull ratio, because it's one of the factors that makes a brake good or not so good. Almost all the switched levers I have ever come across are shorter than long pull but longer than short pull, so they aren't a good match for very many brakes.

I've been messing with e-bikes for 25+ years now and I've never encountered a situation where system disable levers would have helped. Once, my throttle got smashed in a wet surface crash and failed full-on, causing the bike to spin around and around in the lane. But I didn't have easy access to the brake levers while it was doing that.

If I wanted a disable switch for my bike (which I don't), I'd use a "panic button" that I could get to with my other hand while holding the mechanical brake on the powered wheel. I definitely wouldn't use a switch that got cycled on and off all the time in normal operation.

BatteryMan said:

Thanks.

I bought a small 4.5 pound 48V 10AH battery and I'm going to put it inside the frame bag along with the controller.

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Which battery did you buy? I am in the market for one with the same rating for a TSDZ2 mid drive.

Zambam said:

Which battery did you buy? I am in the market for one with the same rating for a TSDZ2 mid drive.

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This is the battery I bought:



I'm going for a stealth look on my bike and also based on my experience with the 52V 13AH battery (I get about 40 miles out of it the way I use it, throttle as needed, or gently pushing down on it say 50%) the 10AH battery if perfect for me. I could always buy another one (or two) and take it with me if needed.

One thing I have learned about ebikes is buy the battery that you need based on your riding needs. No need to buy a giant 20AH battery if you don't even come close to using all of it.

BatteryMan said:

This is the battery I bought:

Amazon.com

I'm going for a stealth look on my bike and also based on my experience with the 52V 13AH battery (I get about 40 miles out of it the way I use it, throttle as needed, or gently pushing down on it say 50%) the 10AH battery if perfect for me. I could always buy another one (or two) and take it with me if needed.

One thing I have learned about ebikes is buy the battery that you need based on your riding needs. No need to buy a giant 20AH battery if you don't even come close to using all of it.

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Have you received the battery and run it yet? Curious of your thoughts on it.

Zambam said:

Have you received the battery and run it yet? Curious of your thoughts on it.

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Looking at the rating reviews, the 1, 2, and 3 star ratings appear identify the issue that after a few charge cycles the battery won’t charge. 1, 2, and 3 make up 18% of the ratings. To me that symptom indicates unmatched cells and a non-balancing BMS, that is cutting out under use or while charging, when one or more groups is bad and can’t be balanced. My guess is the pack has a non balancing BMS, and generic (non brand) cells.

I have received the battery but haven't run it yet. Still waiting for Amazon to deliver my Schwable Marathon HS 420 tire. It's the only battery I found that was rectangular and small.

Lunacycle used to sell a small battery by the name of "The Mighty Mini" but they stopped making it.

I've been messing with e-bikes for 25+ years now and I've never encountered a situation where system disable levers would have helped

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My experience couldn't be more different. I benefit from being able to feather my brake lever to disable the motor irrespective of throttle about a dozen times every commute to work with my rear hub ebike. Namely every single traffic light.

It takes twice as long to cross an intersection from a stop if I have to roll on the throttle. Always keeping the throttle down full and just disabling the motor while stopped at the light is much quicker. It's also less work since it's just a single hand motion to go: release the brake, instead of multiple: release the brake, roll on throttle, hold for two seconds until cruise control kicks in.

Theoretically my Baserunner controller might have some throttle ramp delay setting I could remove to get near similar intersection crossing times, but it would still be more hand work regardless.

For fast pull away at say traffic lights I prefer the Tongsheng, hands on the brakes, foot on the pedal ready, direct you release the brakes you go. On the hand tail 3d printed the battery housing. 500w drive with 48v 20ah battery.

Inanek, your method is unnecessarily risky. If you pull the brake lever firmly instead of feathering it, you won’t launch into traffic if the brake switch system fails in any way.

Stopping is completely different from take off once the light turns green. I have a geared hub motor with a clutch anyway, so nothing electric involved in that.

All of these stop light techniques are bike specific. I have a cutoff switch on my right lever. I only have it because I was planning on using cruise control so I put it on the rear brake. Logically, you wouldn’t want to drive the same wheel you’re braking anyway, so it doesn’t really interfere or come into play during normal riding. I brake mainly with my front brake (like motorcycles), so the cutoff isnt in use at a stop light. I have the CA throttle ramp set so with the controller is set to low, the bike won’t wheelie on takeoff if you apply less than half throttle. After 15mph or so, I can give it more throttle to get up to speed then switch to PAS. This puts me a comfortable distance ahead of the cars, so I’m not immediately having to deal with them. For emergencies, my power button is next to my left thumb, and I’ve used it.
You need a cutoff if you use cruise control. A cutoff may be helpful for PAS depending on the setup (the cutoff allows me to set a long delay before PAS stops assisting, but the ability to cut assist when necessary, otherwise I could live without it).
For the OP’s bike, a cutoff on the front brake lever is probably more than enough.