OK to feather my thumb throttle?

[Jeremy McCreary]

Q: Thought my thumb throttle was all-or-nothing, but turns out that it can be feathered over a very narrow range of middle lever positions. Any electrical reason not to take advantage of this?

NB: Not looking for permission or approval to want or use a throttle, please. Just an answer to a strictly technical question. Thank you.

Background: Wife and I have identical torque-sensing 2023 Surface 604 V Rooks with 500W Bafang G020 rear hub motors. I use my throttle a few times per ride for instant bursts of speed. She uses hers to augment the PAS for prolonged periods while still pedaling, as her knees are even worse than mine. Both of us always pedal.

NB: That's just how she rolls. Trust me, trying to litigate her riding style will do none of us any good.

So, asked her how she managed that with an all-or-nothing throttle. And she said, "What are you talking about? I can get as much or as little help from it as I want."

Well, sure enough, she's right. If 0% is throttle lever not depressed, and 100% is fully depressed, you can get a smoothly progressive boost in motor power, all the way to full motor power, over roughly the 40-60% lever range. And with practice, that's actually pretty useful.

Now, if a lot of amps were going through that thumb switch, feathering power like that would probably be a bad idea from a purely electrical standpoint. But guessing that the thumb switch just provides a low-voltage, low-current signal to the controller. Correct? @AHicks , @m@Robertson?

Many thanks for your technical help on this!

 

[scrambler]

A good throttle should have a progressive range.
Unfortunately a lot of cheap ones barely do.

It is mostly useful if your motor is powerful enough and you are using the high-power mode though.

The Motor amps do not go through the throttle. The throttle just modulates a 0 to 5V signal to the controller

 

[Jeremy McCreary]

A good throttle should have a progressive range.
Unfortunately a lot of cheap ones barely do.

It is mostly useful if your motor is powerful enough and you are using the high-power mode though.

The Motor amps do not go through the throttle. The throttle just modulates a 0 to 5V signal to the controller

Many thanks! No need to be at high PAS to get a useful effect on our bikes.Throttle responses are exactly the same at every PAS level above 0 (throttle disabled). The design works quite well — even better now that I know that the throttle's actually progressive!

 

[scrambler]

Good. Sometimes the throttle shares the power limitation of the PAS.
Definitely more useful when it does not.

 

[JRA]

An electronic throttle is not unlike a simple household dimmer switch. However there are parameters that can allow it's sensitivity via voltage to be adjusted via the controller but if you can't access them via programming with the model of bike/controller you have then you just have to adjust the way it performs. But in all cases there should be some range between off and fully on as they are not like a regular light switch. Might take a delicate touch to achieve and not be very easy to maintain a consistent level however depending.

 

[Jeremy McCreary]

An electronic throttle is not unlike a simple household dimmer switch. However there are parameters that can allow it's sensitivity via voltage to be adjusted via the controller but if you can't access them via programming with the model of bike/controller you have then you just have to adjust the way it performs. But in all cases there should be some range between off and fully on as they are not like a regular light switch. Might take a delicate touch to achieve and not be very easy to maintain a consistent level however depending.

Yes, getting progressive throttle on our bikes does take some practice, but K mastered it long ago, and I'm trained up now, too.

When we bought the bikes, I somehow had it in my head that the throttles were just on-off. Blew right through the narrow progressive band without noticing for 10 months. Duh.

 

[Nvreloader]

JM
I installed a left hand twist throttle on my Wart Hog 750 MD,
thumb throttle broke/quit working.
I left a plastic insert out (by accident), when installing and found that I had a very adjustable twist cruise control throttle, that will set and hold any speed I want from a couple mph to full throttle max speed.
I have used it several times on rutty wash board roads and it hold the speed set.
I am tickled with it's use now.
Tia,
Don

 

[tomjasz]

A good throttle should have a progressive range.

And which throttle is that?

 

[Jeremy McCreary]

JM
I installed a left hand twist throttle on my Wart Hog 750 MD,
thumb throttle broke/quit working.
I left a plastic insert out (by accident), when installing and found that I had a very adjustable twist cruise control throttle, that will set and hold any speed I want from a couple mph to full throttle max speed.
I have used it several times on rutty wash board roads and it hold the speed set.
I am tickled with it's use now.
Tia,
Don

Yeah, this new-found progressive throttle technique is turning out to be a pretty handy riding tool. If I plant one side of my thumb on the throttle housing and roll the other side onto the lever, I can hold a desired boost pretty well, though probably not as reliably as you can.

That said, surprising utility in a simple on-off throttle once you learn to take full advantage. Just recently learned that I can lose less speed by using blips to help unload my chain for steep uphill downshifts.

 

[Gionnirocket]

And which throttle is that?

I've used twist and half twist both with progressive full range of the motors output.

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[harryS]

The throttle is a cool application of a magnetic sensor chip.
.
There's a magnetic ring that rotates past the chip,.

.
The chip is a three wire device, with power, ground, and output which varies from a half volt to 4 volts depending on the magnet position.
.
The parts probably cost about 50 cents, and it took me about a half hour to reassemble properly after I opened it up.

 

[Jeremy McCreary]

The throttle is a cool application of a magnetic sensor chip.
.
There's a magnetic ring that rotates past the chip,.
View attachment 159611
.
The chip is a three wire device, with power, ground, and output which varies from a half volt to 4 volts depending on the magnet position.
.
The parts probably cost about 50 cents, and it took me about a half hour to reassemble properly after I opened it up.

Thanks for showing me the innards! Spurred me to look up the Wikipedia page on Hall sensors. Never realized how indebted my daily life has become to Edwin Hall. Hug a physicist.

 

[gromike]

I love the right twist throttle. When you need to pull some speed it is so handy. For brief moments of need I will run with the cars.

 

[Gionnirocket]

The throttle is a cool application of a magnetic sensor chip.
.
There's a magnetic ring that rotates past the chip,.
View attachment 159611
.
The chip is a three wire device, with power, ground, and output which varies from a half volt to 4 volts depending on the magnet position.
.
The parts probably cost about 50 cents, and it took me about a half hour to reassemble properly after I opened it up.

I put a bigger magnet in mine and now my bike can go 40 mph on throttle

 

[prixat]

I have one of the cheaper thumb throttles with barely any effect between off and full.
Would a 'better' thumb throttle have a more gradual effect?

Any recommendations?

 

[AHicks]

Now, if a lot of amps were going through that thumb switch, feathering power like that would probably be a bad idea from a purely electrical standpoint. But guessing that the thumb switch just provides a low-voltage, low-current signal to the controller. Correct?

YUP!

Yeah, this new-found progressive throttle technique is turning out to be a pretty handy riding tool. If I plant one side of my thumb on the throttle housing and roll the other side onto the lever, I can hold a desired boost pretty well, though probably not as reliably as you can.

This is exactly how I manage a thumb throttle! Works to hold the throttle steadier/especially well in bumpy terrain or when managing BIG power (e.g. 150+hp snowmobiles and other high powered off road toys, ALL of which use thumb throttles).

 

[6zfshdb]

If you're a DIY'er, you can emulate the throttle hall sensor using a simple voltage divider circuit

That way, you can dial in any speed using a rotary variable resistor. The switch lets you choose between throttle or "cruise control"

I use them on all my bikes. Here's a link detailing how it's done:

Adding a Rotary Dial Speed Control

I occasionally get a cramp in my right hand when using my half grip twist throttle. As a remedy, I built this small control box as an alternate way to adjust speed. In doing some research, I discovered a 3 wire hall effect throttle can be emulated with a variable resistor. I wired the control...

forums.electricbikereview.com

 

[Old-tool-guy]

I don’t understand the contempt and derision toward throttles. I use mine to get started from a stop, cuz i’m a lot older than when i rode my Schwinn with coaster brakes “back in the day”. One foot on a pedal, butt touching the seat, other foot on the ground for balance. Give it partial throttle, gets me moving and gives me 5 - 10 seconds to fully mount the bike. Other than that i rarely use it.

 

[Robert R]

I don’t understand the contempt and derision toward throttles. I use mine to get started from a stop, cuz i’m a lot older than when i rode my Schwinn with coaster brakes “back in the day”. One foot on a pedal, butt touching the seat, other foot on the ground for balance. Give it partial throttle, gets me moving and gives me 5 - 10 seconds to fully mount the bike. Other than that i rarely use it.

I also use my throttle when I'm starting up and sometimes when I'm riding slowly as it feels a bit more controllable than the pedal assist (my PAS only has speed settings and not power settings).

 

[PCeBiker]

YUP!

Yeah, this new-found progressive throttle technique is turning out to be a pretty handy riding tool. If I plant one side of my thumb on the throttle housing and roll the other side onto the lever, I can hold a desired boost pretty well, though probably not as reliably as you can.

This is exactly how I manage a thumb throttle! Works to hold the throttle steadier/especially well in bumpy terrain or when managing BIG power (e.g. 150+hp snowmobiles and other high powered off road toys, ALL of which use thumb throttles).

That's what I do as well.
I can give my throttle housing a tiny nudge to increase or decrease my speed by ½ kph increments.

I glued sand paper to the housing and melted lines in the plastic with a hot knife to give it more grip.
The housing is pretty snug against the handlebar so it doesn't move by accident or vibration.


HOWEVER !!
Keep in mind if you ever come off your bike, the bike keeps going !!
At least until it falls over and hopefully the powered wheel is no longer touching the ground.
Ask me how I know.