Brake cut out switches - are they essential

Electrically assisted bikes, trikes, etc. that are legal in the UK
saudidave
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Brake cut out switches - are they essential

Post by saudidave »

I've just pre ordered two of the new Swytch kits launched today with a 60% discount and I can apparently order two optional extras at a later point; A throttle and a brake cut out kit that cuts power to the motor when the brakes are applied.

I won't be bothering with a throttle but I'm not sure about the brake cut outs. Are they really neccesary? surely if one is braking then you stop pedalling anyway. Can any one with experience offer any advice please?
fivebikes
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Re: Brake cut out switches - are they essential

Post by fivebikes »

I have two Swytch converted Brompton bikes without the brake cut outs. They are absolutely fine! As you say, the assistance cuts as soon as you stop pedalling.
I also have an ARCC Moulton, with the cut outs. On the first couple of rides I was aware the assistance had gone, instantly the brakes were applied, but I don’t notice it now!
So my experience is that on the Swytch you’re probably fine without them. I’ll check the Moulton next time and see if I notice a difference and report back!
I’m happy with both but didn’t want to spend more on the Brompton conversions. If I had felt unsafe though, I would have ordered them at a later date!
Bonzo Banana
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Re: Brake cut out switches - are they essential

Post by Bonzo Banana »

In theory brake cut off switches will stop the motor more instantly and therefore increase safety but for people who convert road and gravel bikes to ebikes with ebike kits who often have no way of installing the supplied V/Mechanical disc brake levers that come with ebike kits you don't hear them complaining about reduced braking safety and those are the fastest types of bikes.

I feel like if you are cycling a lot in urban traffic with congestion and relying on your brakes more for emergency stopping perhaps brake cut off switches are more essential. Sometimes you can be right up close to other vehicles and any small delay in the brakes stopping the bike could make it more tricky. When I was a kid I used to have a Raleigh Chopper and the caliper brakes on that working on steel rims were slow to bring you to a stop for sure and you rode accordingly.

If you are happy with braking performance without cutoff switches then I feel that is all that matters.
stodd
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Re: Brake cut out switches - are they essential

Post by stodd »

For me the cutoff switches are not important for breaking. However they are important for awkward slow speed manoeuvring (eg around barriers). You don't want the motor to cut in suddenly, and if it does you want to turn it off again asap.
saudidave
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Re: Brake cut out switches - are they essential

Post by saudidave »

Thanks to everyone for their responses. I shall try them without and can always fit them later if needed
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Cowsham
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Re: Brake cut out switches - are they essential

Post by Cowsham »

I tried them without for the wife's trike -- the main problem was that the motor doesn't cut immediately after you stop pedaling so you get dragged deeper into corners than you would intend.

On a trike that's very bad cos it will tend to tip you off if cornering too fast. I'd say bikes could result in a low side -- losing the front as your pulled too fast into the corner.

The brake switch cured that problem.
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saudidave
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Re: Brake cut out switches - are they essential

Post by saudidave »

Cowsham wrote: 6 May 2022, 7:50pm I tried them without for the wife's trike -- the main problem was that the motor doesn't cut immediately after you stop pedaling so you get dragged deeper into corners than you would intend.

On a trike that's very bad cos it will tend to tip you off if cornering too fast. I'd say bikes could result in a low side -- losing the front as your pulled too fast into the corner.

The brake switch cured that problem.
Noted, that's a potential game changer for me so I may fit them
yakdiver
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Re: Brake cut out switches - are they essential

Post by yakdiver »

Not had any brake cut out on my e-trike in the last 6 years, so far so good
fivebikes
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Re: Brake cut out switches - are they essential

Post by fivebikes »

Cowsham wrote: 6 May 2022, 7:50pm I tried them without for the wife's trike -- the main problem was that the motor doesn't cut immediately after you stop pedaling so you get dragged deeper into corners than you would intend.

On a trike that's very bad cos it will tend to tip you off if cornering too fast. I'd say bikes could result in a low side -- losing the front as your pulled too fast into the corner.

The brake switch cured that problem.
Interesting observation. I haven’t noticed that phenomena but I understand what you’re saying.
On a small wheeler, like a Brompton, the front can be a bit skittish in the wet. Next time I’m out I’ll be more observant.
I tried the Moulton as I said I would earlier in the thread. I only noticed the instant cut out when at a junction between a steep side road and a flatter side road. I felt the instant loss of power a bit of a hindrance to be honest. The Swytch at the same junction seems to give a little more help when joining….. If the coast is clear! If I have to stop completely, then doesn’t seem to make any difference. Obviously, travelling very slowly at that point!
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Cowsham
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Re: Brake cut out switches - are they essential

Post by Cowsham »

yakdiver wrote: 7 May 2022, 1:35pm Not had any brake cut out on my e-trike in the last 6 years, so far so good
Depends what kind of trike -- if it's an upright one it's a bit more tipsy or top heavy -- and any slight delay in the motor slowing as the electronics decide whether or not you're pedaling is a bit disconcerting.

Noticed if I turn and tip it up onto two wheels with the drive wheel up off the ground ( driven by cassette rear wheel ) the front electric wheel keeps the trike in the turn with the driven wheel spinning in mid air. Quite a weird feeling.
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yakdiver
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Re: Brake cut out switches - are they essential

Post by yakdiver »

Cowsham wrote: 7 May 2022, 3:12pm
yakdiver wrote: 7 May 2022, 1:35pm Not had any brake cut out on my e-trike in the last 6 years, so far so good
Depends what kind of trike -- if it's an upright one it's a bit more tipsy or top heavy -- and any slight delay in the motor slowing as the electronics decide whether or not you're pedaling is a bit disconcerting.

Noticed if I turn and tip it up onto two wheels with the drive wheel up off the ground ( driven by cassette rear wheel ) the front electric wheel keeps the trike in the turn with the driven wheel spinning in mid air. Quite a weird feeling.
Recumbent trike - three wheels
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Cowsham
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Re: Brake cut out switches - are they essential

Post by Cowsham »

yakdiver wrote: 7 May 2022, 9:16pm
Cowsham wrote: 7 May 2022, 3:12pm
yakdiver wrote: 7 May 2022, 1:35pm Not had any brake cut out on my e-trike in the last 6 years, so far so good
Depends what kind of trike -- if it's an upright one it's a bit more tipsy or top heavy -- and any slight delay in the motor slowing as the electronics decide whether or not you're pedaling is a bit disconcerting.

Noticed if I turn and tip it up onto two wheels with the drive wheel up off the ground ( driven by cassette rear wheel ) the front electric wheel keeps the trike in the turn with the driven wheel spinning in mid air. Quite a weird feeling.
Recumbent trike - three wheels
The tipping over problem would be replaced with a slight tail drift or under steer problem but won't be as big a problem with the two wheels at the front.
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Beaker
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Re: Brake cut out switches - are they essential

Post by Beaker »

Cowsham wrote: 6 May 2022, 7:50pm I tried them without for the wife's trike -- the main problem was that the motor doesn't cut immediately after you stop pedaling so you get dragged deeper into corners than you would intend.

On a trike that's very bad cos it will tend to tip you off if cornering too fast. I'd say bikes could result in a low side -- losing the front as your pulled too fast into the corner.

The brake switch cured that problem.
The motors also kick back in quickly. Turn the crank to get the inside pedal at the top for taking a corner and the motor will start pulling again.

I wouldn't want an ebike without brake sensors.
UpWrong
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Re: Brake cut out switches - are they essential

Post by UpWrong »

I'd want them because .... when coasting to a stop I want to change down on the rear derailleur to a lower gear for starting off, and the ghost pedalling to shift fires up the motor with a cadence sensor. Having the cut-outs means this can be nullified as you surge towards the stop/give-way line.
fivebikes
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Re: Brake cut out switches - are they essential

Post by fivebikes »

UpWrong wrote: 24 May 2022, 10:06am I'd want them because .... when coasting to a stop I want to change down on the rear derailleur to a lower gear for starting off, and the ghost pedalling to shift fires up the motor with a cadence sensor. Having the cut-outs means this can be nullified as you surge towards the stop/give-way line.
On my Swytch Brompton, without cut outs, this isn’t an issue as the SA hub gear changes up or down with a momentary pause in pedal pressure. It does have a simple two cog derailleur, to make the six speeds, but I save that for when I’m underway. The ARCC Moulton is oldish, with the SRAM hub and 9 speed derailleur arrangement. I probably do shift down on the cassette as I brake….Never consciously thought about the cut outs helping then. I’ll give it a spin and see what I do to drop through the gears.
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