Warning ! On cheap throttle.

[hillslayer@]

Nobody here probably gambling on using these but figured l would let you know these things will out of nowhere go full throttle with out touching them.
I just found this on AliExpress:
Electric Bike Bicycle Twist Throttle High Medium Low Speed Forward Reverse Speed Control Without Switch Acceleration Handle

https://a.aliexpress.com/_m0CLZhl

 

[hillslayer@]

I tried more than one same thing, things are deadly.

 

[docw009]

Lose the ground connection and you get full throttle. That's built into every Hall effect throttle, Has happened on 3 of my ebikes. That's why I install brake switches.

 

[hillslayer@]

Brake switches don't help if you don't have your hand on them. So not all throttles use this Hall effect I take it, I only had a problem with these dirt cheap ones.

Lose the ground connection and you get full throttle. That's built into every Hall effect throttle, Has happened on 3 of my ebikes. That's why I install brake switches.

 

[yooper2001]

For $3.59 what can you expect? They must have a 95 year old homeless cripple in the sweat shop making these for that cheap.

Out of recycled components none the less.

 

[OlderGiantFan]

When I'm riding I'm mostly near full throttle anyway
So I doubt the issue would effect me. Mind you I'd never buy any throttle that cheap. I did buy a half twist and found I had to mount it on the LH bar end because my mirror sits in the RH end. This made it work in reverse naturally. One day at a cross roads I grabbed the bar fully after braking and inadvertently twisted it forward, which was power on, and found myself sailing across the intersection. Never again, I reverted to the thumb throttle, much safer considering how much weight I put on the bars. The thumb throttle was a well thought out design imo.

 

[99t4]

So not all throttles use this Hall effect I take it, I only had a problem with these dirt cheap ones.

There are two main ebike throttle types: Hall effect, and potentiometer. Hall effect throttles are by far the grand majority.

 

[OlderGiantFan]

There are two main ebike throttle types: Hall effect, and potentiometer. Hall effect throttles are by far the grand majority.

Which would you consider the better design? Considering factors like longevity, reliability, and probably most importantly, efficiency as in getting good speed modulation. I know from experience with potentiometers in other applications they can sometimes develop flat spots so to speak, but never can they go faulty and cause max power to be delivered. At least not in my experience.

 

[99t4]

Which would you consider the better design?

For me, commodity-level hall effect halftwist grip or thumb lever work fine for me but remote potentiometer throttle work better for certain other formats (AW for example uses remote potentiometer throttles). I am not in a position to proclaim one is a better design over the other.

 

[Matt Gruber]

Lose the ground connection and you get full throttle. That's built into every Hall effect throttle, Has happened on 3 of my ebikes. That's why I install brake switches.

thanks for giving me a good reason to hook up my brake switch

 

[mrmojorising]

I know from experience with potentiometers in other applications they can sometimes develop flat spots so to speak.

I'd say that's the main wear consideration. Pots having moving parts so tend to wear quicker, while halls are incredibly simple and reliable. Plus you can replace halls easily and cheaply. Analog hall sensors can be purchased for less than 10-20 cents. Most throttles I've seen use a 49E hall sensor or similar

 

[OlderGiantFan]

I'd say that's the main wear consideration. Pots having moving parts so tend to wear quicker, while halls are incredibly simple and reliable. Plus you can replace halls easily and cheaply. Analog hall sensors can be purchased for less than 10-20 cents. Most throttles I've seen use a 49E hall sensor or similar

Well the jury is out and it's unanimous. Great technology.

 

[RunForTheHills]

For $3.59 what can you expect? They must have a 95 year old homeless cripple in the sweat shop making these for that cheap.

Out of recycled components none the less.

Why would you hire a 95 year old cripple when a 10 year old can do the job better and cheaper...

 

[docw009]

Which would you consider the better design?

It's more about the cheapest design. A Hall IC has no moving parts. unlike a potentiometer which requires its own axle/wiper. The mechanism below works for a thumb throttle. Solder the cable to a Hall chip, Spin a magnet over it, Twist throttles are the same design,. They snap in a handle bar grip instead of the thumb piece. I've never been able to unsnap the grip off a twist throttle,



We've ridden thru 6" water and had the throttles turn on (weakly) afterwards, but those bikes had open JST connectors where dirty water must have bridged the throttle signal,

Lose the ground on a Hall chip, and the signal floats to Vcc (5V power supply) minus a diode drop, about 4.3V. That's recognized as full throttle.

Lose the ground on a potentiometer and the signal becomes Vcc. No problem, Most controllers will not recognize throttle signal if it is the same as the throttle supply.

 

[99t4]

I've never been able to unsnap the grip off a twist throttle,

Easy-- just need to insert the correct size pipe to unlock all 3 locking tabs simultaneously and the grip slides off. I use a cut section from an old aluminum folding chair.

 

[OlderGiantFan]

Lose the ground on a Hall chip, and the signal floats to Vcc (5V power supply) minus a diode drop, about 4.3V. That's recognized as full throttle.

Thanks for the detailed explanation and pic. I get it all now. Motorcycles have an engine kill switch, which almost seems redundant since the key does that. But a rocker kill switch on these throttles sounds like it might be a good idea give the consequences of a bad ground. That could be caused by something as simple as a grotty pin or a crimped cable down below couldn't it? Bit of a spooky thought. I had my bike runaway on me some months back when I was experimenting with a twist grip half throttle mounted in reverse, it's not a nice feeling being suddenly propelled across an intersection at full power. Of course all I had to do was let go of the grip, but since I was suddenly shot forward my instinct was to hold onto that grip, for dear life

 

[mrmojorising]

Thanks for the detailed explanation and pic. I get it all now. Motorcycles have an engine kill switch, which almost seems redundant since the key does that. But a rocker kill switch on these throttles sounds like it might be a good idea give the consequences of a bad ground. That could be caused by something as simple as a grotty pin or a crimped cable down below couldn't it? Bit of a spooky thought. I had my bike runaway on me some months back when I was experimenting with a twist grip half throttle mounted in reverse, it's not a nice feeling being suddenly propelled across an intersection at full power. Of course all I had to do was let go of the grip, but since I was suddenly shot forward my instinct was to hold onto that grip, for dear life

Good controllers usually handle these issues, even cheap ones like the Flipsky ft85bd I'm using on an escooter has a feature called "safe start" which will disable throttle if it detects abnormal throttle voltage on startup. You can also enable a feature that requires you to depress the brake (aka active the brake sensor) before throttle is enabled

So cheap throttles aren't usually the problem, it's often cheap or "dumb" controllers

But yeah a simple switch on the throttle wire is another cheap and easy solution. I also like the idea of indicator lights on throttles (similar to the lekkie throttle) to show when they're live

 

[OlderGiantFan]

But yeah a simple switch on the throttle wire is another cheap and easy solution.

I was going to install such anyway, since down here throttles, "functional throttles" are illegal. If for some reason I was ever pulled over I could just flip the hidden micro-switch and claim the thumb throttle came with the bike but was deactivated for Australian law. Mounting it near the bottle cage would be good, I'll have to look at where the wire is routed. Then of course you play dumb and ask if you should take it to a bicycle shop and have it removed. What can they say