What do you think of my new bike?

[guerney]

1.One needs brake sensors if one has a throttle, so more to go wrong, also I like to keep my bike as clutter free as possible.

Are you saying you don't have brake sensors? I've got vbrakes, and really don't think it'd be safe fighting my PAS with those. Besides, brake pads aren't cheap, or as cheap as I'd like them to be - I've been getting through them at a rate of knots since converting.

 

[Nealh]

I don't use brake kill switches simply because I use KT controllers and no thumb throttle , other contollers and their programming may differ to how much over run the PAS has so brake kill switches may be deemed necessary.
If I utilised a thumb throttle then I would use a kill switch as in the past I have exp throttle failure so know how important a kill switch is.

 

[guerney]

other contollers and their programming may differ to how much over run the PAS has so brake kill switches may be deemed necessary.

It'd be suicide for me, especially now I've increased the controller limit from 15A to 18A, there's even more torque, and particularly for technical bits offroad - which thankfully for me is extremely rare - when I need the capability of rapid cesssation of motor power to stop my overshooting and falling off things. Two ebrakes also come in handy negotiating tightly packed rush hour traffic.

 

[Waspy]

Are you saying you don't have brake sensors?

Woosh said I didn't need brake cut-outs if I chose to not have a throttle.

One assumes they know what they are talking about.

 

[saneagle]

No doubt you'll destroy my case with your massive brain of super-knowledge

Let's see what my massive brain can do:
1. I have a throttle, but no brake sensors. My bike has been like that since 2014, and I'm still happy without them.
2. It's true that full-width throttles are easy to brake, but thumb throttles are pretty robust and well protected. Even if you did break one. Most bikes have an off-switch these days, which you can operate, while you take 10 seconds to disconnect the throttle or cut the wires before switching back on.
3. No throttles are illegal and it's not illegal to have one on your bike. Any laws relate to the way you use them. With the right controller (KT), you can get just about everything you need from the throttle completely legally. When the police find those illegally operated 1500w bikes with independent throttles, it's easier to prove the illegal use of the throttle than the motor being rated above 1500w unless it has a 1500w label on it. You can't go by size because the legal direct drive motors are about the same size as the illegal ones, while as if they press the throttle and the motor spins up to 30 mph, it's a slam dunk.

 

[saneagle]

It'd be suicide for me, especially now I've increased the controller limit from 15A to 18A, there's even more torque, and particularly for technical bits offroad - which thankfully for me is extremely rare - when I need the capability of rapid cesssation of motor power to stop my overshooting and falling off things. Two ebrakes also come in handy negotiating tightly packed rush hour traffic.

As he said, it's just the motor run-on that matters. The run-on is a characteristic that you only get with pedal assist. The power doesn't matter, but the time does. Some controllers run the motor for up to 2 seconds after you stop pedalling, for which you definitely need good break sensors. Throttles always cut off instantly except when you already have the run-on from pedalling.

I had one bike, where I would be pedaalling along at low throttle, then, when I wanted to slow down, I'd let go the throttle and stop pedalling, and the bike would go to full power for two seconds because of the pedal assist run-on that was working in the background, but over-ridden by the throttle until I let go.

 

[guerney]

As he said, it's just the motor run-on that matters. The run-on is a characteristic that you only get with pedal assist. The power doesn't matter, but the time does. Some controllers run the motor for up to 2 seconds after you stop pedalling, for which you definitely need good break sensors. Throttles always cut off instantly except when you already have the run-on from pedalling.

I had one bike, where I would be pedaalling along at low throttle, then, when I wanted to slow down, I'd let go the throttle and stop pedalling, and the bike would go to full power for two seconds because of the pedal assist run-on that was working in the background, but over-ridden by the throttle until I let go.

I've got firmware set to stop power quite abruptly when pedalling stops, but there's only so much abruptness my damaged knees can cope with (there's the same fast decline in motor power at 25kph, which when you're pedalling hard at the time, can result in knee pain). The ebrakes are useful, for me at least. If other people have no have no problem stopping too, it's not a problem that needs solving.

 

[Woosh]

Are you saying you don't have brake sensors? I've got vbrakes, and really don't think it'd be safe fighting my PAS with those. Besides, brake pads aren't cheap, or as cheap as I'd like them to be - I've been getting through them at a rate of knots since converting.

1. I have a throttle, but no brake sensors. My bike has been like that since 2014, and I'm still happy without them.

Imagine the throttle gets stuck. Your big brain can figure out instantly what to do but for other people without the knowledge of the inner working of the electronics, they would panic and squeeze the brakes even when there is a cutout button on the the throttle.
Without the brake sensors, they'll blow the controller and may even end in A&E and I'll get a call from their no win no fee lawyers.

2. It's true that full-width throttles are easy to brake, but thumb throttles are pretty robust and well protected. Even if you did break one. Most bikes have an off-switch these days, which you can operate, while you take 10 seconds to disconnect the throttle or cut the wires before switching back on.

you may never have experienced a stuck throttle but ordinary users would never think of checking their throttle until something goes wrong during their rides so you have to anticipate that possibility.

 

[Woosh]

The run-on is a characteristic that you only get with pedal assist.

Agreed. That's why I think the BBTS is a better solution. The start/stop on the BBTS are similarly instantaneous to throttle control. I can send you one to try whenever you wish.

 

[Peter.Bridge]

I can send you one to try whenever you wish.

I for one would be very interested in @saneagle 's impression of the bbts kit

 

[saneagle]

I for one would be very interested in @saneagle 's impression of the bbts kit

I hope to try it sometime. If the controller uses a torque multiplication algorithm, I wouldn't be so keen on it. I prefer to always have the choice on how hard I pedal. It doesn't make sense to me to have to pedal harder to get more assistance. A torque sensor that works as a switch would be good with a current control controller that you could set the current at any value with a slider or unsprung throttle-like input would be perfect.

 

[Hoppy33]

Brake cut-out switch is a very important safety feature.

- When my 2 year-old grandson is in the front seat (Thule Mini, we have wonderful rides together) he can reach everything and loves pressing things, regardless of instructions - including the thumb throttle. If I’ve forgotten to switch off when we stop, the brake switch can literally be a lifesaver. I’ve not made that mistake twice.
- In the car, I was waiting at a busy zebra crossing while a guy was walking his ebike across. It was a DIY conversion so caught my eye. Suddenly his pedals started turning and in the same instant the bike reared off in front of him. He managed to keep hold of one handlebar momentarily but it was too late and the bike careered off and crashed on the other side of the road. The rider was sprawled on the ground though dusted himself down okay, but it was pure fluke that nobody else was hurt, with mums and prams about. That can happen so easily with a sticky freewheel, with or without a throttle.*

I also use the brake cut-out as a clutch when changing down approaching a junction. You obviously have to pedal to change gear but don’t want any power, so a light touch on the brake just kills the motor.

*Edit: Something similar almost happened to me when I was walking the bike around the back of the house. It suddenly lurched forward violently but thankfully I caught it with the brake cut-out. This was not a case of poor maintenance, but some long grass that, unknown to me, had tangled itself around the freewheel and prevented it from, well, freewheeling.

 

[Peter.Bridge]

I also use the brake cut-out as a clutch when changing down approaching a junction. You obviously have to pedal to change gear but don’t want any power, so a light touch on the brake just kills the motor.

Yes - exactly - that is when I use the brake sensor with my bike that has a cadence sensor. With the BBTS kit I can ghost pedal (to change down the gears) without the motor kicking in as I am not applying pedalling force

 

[Peter.Bridge]

I hope to try it sometime. If the controller uses a torque multiplication algorithm, I wouldn't be so keen on it. I prefer to always have the choice on how hard I pedal. It doesn't make sense to me to have to pedal harder to get more assistance. A torque sensor that works as a switch would be good with a current control controller that you could set the current at any value with a slider or unsprung throttle-like input would be perfect.

I think it does have some sort of torque multiplication algorithm, but one of the parameters on the LCD (that I haven't altered !) is pedal sensitivity - don't know what effect this has. In practice I don't really notice the assist level changing - but I suspect my version of "gentle" pedalling seems to trigger max power for that assist level ! (but I am quite burly !)

 

[afzal]

The start/stop on the BBTS are similarly instantaneous to throttle control.

Isn't there any noticeable lag at start/stop ?

Torque exerted by the rider is pulsating (peaking twice) in a pedal rotation, to avoid jerky motion (& thus a pleasurable ride), normally controller does a low pass filter (plus ramp) over torque sensor input, this in effect causes a lag.

The above effect becomes noticeable when the motor power goes up, probably the reason that people have noticed run on with Bafang Ultra, but not with TSDZ2, suspecting that peak power of BBTS controller is similar to that of TSDZ2

 

[guerney]

probably the reason that people have noticed run on with Bafang Ultra, but not with TSDZ2

There doesn't appear to be a "Stop delay" parameter in the Ultra's configurator.

I Void Warranties : Hacking The Bafang Ultra Max Mid-Drive Ebike Drive

There is half a dozen low power torque sensing mid drives on the market right now that advertise themselves as being between 250 and 750 Watts. The one thing that all these ‘low power’ …

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Mine is set to the lowest value the BBS01B will work with, and it's pretty fast, but I still wouldn't forgo ebrakes on my particular bike. With ebrakes, I have a fine control. Sometimes you've just gotta stop.

Bafang Programming - Learn how to improve your Bafang mid-drive ebike - Edrivenet

Learn how to improve your Bafang mid-drive ebike. Reprogramming your Bafang mid-drive system can improve the usability and performance of your ebike a lot.

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[Woosh]

I did not notice any

Isn't there any noticeable lag at start/stop ?

it's pretty close to instantaneous. The built in PAS has 24 counts per revolution.

 

[Wisper Bikes]

Why did I have to read to post 104 to learn that? It should have been right at the top! I will not buy an e-bike without a throttle. Up to 4mph is fine for the very important business of safe (and elegant) launching, and easier low speed manoeuvring. A mid-motor e-bike with throttle has very strong sales appeal, but is an extremely rare beast on this side of the water.

Shame it’s not a step-thu though. With two bionic hips I can’t ride a high-step, let alone with a child on the back or a basket of groceries, and I usually have one or the other. Who can? Wisper it is then.

Just a small point, we can supply a legal full throttle Wayfarer mid motor with a 43V system and 100Nm of torque.

All the best, David

 

[afzal]

There doesn't appear to be a "Stop delay" parameter in the Ultra's configurator.

The firmware running in the controller might still add it without exposing it to the configurator (not saying that is necessarily the case, but that there is a possibility, w/o seeing the firmware source one can't be sure). Also another cause for the lag is low pass filter, parameters of which firmware does not expose the configurator.

AFAIU, Luna has VESC based Bafang Ultra controller, relevant VESC firmware code snippet can be seen in the below links,
1. low pass filter
2. ramp time

Of the above, only ramp time is configurable (by VESC tool running on PC), low pass filter is not configurable (unless you change third arguement & recompile the VESC firmware)

Mine is set to the lowest value the BBS01B will work with, and it's pretty fast

I suspect you might get a smoother ride with a higher value, though if you are happy with the current setting, my opinion is irrelevant

 

[guerney]

The firmware running in the controller might still add it without exposing it to the configurator (not saying that is necessarily the case, but that there is a possibility, w/o seeing the firmware source one can't be sure). Also another cause for the lag is low pass filter, parameters of which firmware does not expose the configurator.

The hackers haven't hacked deep enough.

I suspect you might get a smoother ride with a higher value, though if you are happy with the current setting, my opinion is irrelevant

Makes U-turns easier with the lower value, as I don't want to use the ebrakes which make those maneuvers stally. Besides, ebrakes could fail and I don't wear out my v-brake pads, which saves money.