Brake service and info

[john-smith-2]

With the light weight of the aptera and the regenerative braking it’s going to be a long long time until you have to do brakes.

[BUG]

@Pistonboy Delux (et al) In the Article I posted about the M700, there was some verbiage about changing the Bearings to More Stout ones. apparently? one of the first uses of the M700 was for an electric version of the Smart Car…

And, Engineers being how they are, You know that I will have to Pull the Rotor off at least One of the Motors to admire/inspect everything, after a FewThousand Miles of Motoring.

[david-marlow]

My experience with my 2011 Volt, that has a moderate regen, is that iI replaced the rear pads at about 60k miles and now with 120k miles it still has the original front pads. The way breaking is done on the Volt is that with mild braking just the regen is applied with the Front wheel drive, with Moderate brake pressure the rear pads are applied then with harder braking the front pads are then applied. So by rarely braking hard, the front pads do not get much wear.

[john-malcom]

This is good to know! My son has a gen 1 volt. I am sure he doesn’t know this. I will pass it on. Thanks

[george-hughes]

I suspect the way brake inspections occur is when the in-wheel motors need scheduled maintenance somewhere between 30-60,000 miles. Similar motors from Elaphe probably destined for the ill-fated Lordstown pickup, which was a heavier duty use of the motors, had maintenance set at the lower figure. On the Aptera, lower horsepower, a lot less heat and weight involved suggests the schedule can be extended.

Still, the motor seals – the maintenance required – have to be replaced sometime in the first 75,000 miles and that process will allow precision review of the condition of the brake pads.

Considering the design of in-wheel motors like that used by Aptera provide massive regen that brakes are almost superfluous means they may last longer than even the most optimistic expectations.

[joshua-rosen]

I hope they will use stainless steel brakes. The big problem with brake pads in EVs is not wear, it’s rusting. On Tesla’s you have to clean and lubricate them every now and then, something I never did on an ICE car. On an ICE car the brakes get hot which dries out the water but on an EV they hardly get used so they don’t get heated nearly as often. There are brake pads made for EVs that don’t rust, I hope they know about these. They don’t salt the roads in San Diego so they may not be aware that this is a problem, hope that someone tells them that this is a real issue.

[OZ.]

Joshua, Likely, with the brakes being integral to the wheel motors, enough heat should be generated by the motors to keep them dry.

[V-Pilot]

Do we know the supplier of the brake rotors? Will they be available as a carbon ceramic composite? Regen braking can use little to no brakeing, leading to surface rust build up which can lead to excessive scaling, causing vibration and pad damage on iron rotors.

[Shawgrin]

Because hydraulic brake design the pads are always being in contact with the rotors, this prevent slap, rattle, rust and scale.

[Biker]

@Vernon Michael Gardner Some EV owners who have had to replace brake rotors at less than 20K miles may disagree with you.

[michael-hicks]

The easy solution to this problem is to actually use your brakes periodically to clean any build up off the rotors.

[BUG]

I am sure You will be able to buy Carbon-Carbon Brake Rotors, as soon as the World Pop Realizes that this Wonderful Vehicle is the “New VW Bug”. BONUS: Lighter!

Several of the Vids, Featuring Zips around the Building, and even a few others, have the Brakes Squealing on the BETA/ALPHA Models. I am sure that Pad Selection for the Present Cars, and a Few Strong stops from Speed in a Production Model will remove the Glaze that must be the cause!

[993cc]

In the Elaphe design, the brake rotors are located inside the wheel hubs. They should be well protected from the elements and road salt, at least on the front wheels. I hope Aptera considers drum brakes for the rear on two wheel drive models. Drum brakes are fully adequate for a light car that mostly brakes regeneratively, and they have lower rolling resistance than disks.

[david-marlow]

I was trying to find out how the parking brake worked, the only info I could find is that the in-wheel brakes are electric. So I am thinking that to have a parking brake function would be to have the brakes applied when the power to them is off, then when power is applied the brakes are released. To have a variable amount of brake applied the power to them would be modulated.

[Biker]

Like just about any mainstream vehicle, the Aptera will likely have hydraulic brakes to slow the car and IIRC there’s a second caliper inside the hub for the parking brake function -that one is electric.

[david-marlow]

There is no hydraulic brake connection to the motors (only cooling), there is and electrical connection (other than the 3 phase motor wires). This is another way that Aptera is different from mainstream vehicles. I got the electric brake info from the Elaphe web site.

[colen-thomas]

I am interested in knowing how the parking brake is going to work also. There is no drive train that can be locked. There should be some way that is independent of the vehicle’s electrical system.

[david-marlow]

If the poweer fails, the brake would be applied, as it would take power to keep it from appling. This would be a fail safe system.

Also having a hydraulic brake system would add weight, cost and complexity to the build when the regen should be doing almost all of the stoping. The only other thing needed is the parking brake/ emergency brake function, that is there with the electrical caliper.

[ROMAD]

But there needs to be a non-electric, non-hydraulic, all-mechanical (either cable or rod actuated) back-up emergency/parking brake.

[harry-parker]

Dennis, I know that no all-mechanical emergency brake is needed, because my 2014 Chevy Volt doesn’t have one. Its parking brake is electrically operated from push/pull lever switch on the dash. Many cars now work this way. I can hear a small electric motor presumably pull on or release tension on the brake when I use it. I’m guessing it runs off the 12 volt battery.

However on the Volt the brakes are hydraulic and Park engages a pall that prevents the car from moving, as on most cars.

If I forget to release the parking brake, the Volt does it for me once it’s in gear and I press on the accelerator. Those smarts have prevented me from doing what I once did on an old car: drive for close to a mile with the parking brakes on, effectively ruining those brakes.

Don’t know what happens if the 12 volt electric power suddenly fails, though on my Volt nothing would then work. The car would turn totally off. You need 12 volts to get the computers working to start and control the car, including getting it out of park. I’ve accidentially turned the car off while driving by pushing the Start button twice (ignoring the warning message and audio alarm), thinking I was pushing the Drive mode button just above it. (Bad button layout!) All I could do at that point was coast and brake gently (hydraulically) to get to the side of the road and stop. Only then could I restart the car.

[ROMAD]

So if all power failed and the computers died, you would have to coast to the side and stop using your hydraulic brakes. However once stopped, if you weren’t on a level area, as soon as you took your foot off the brake pedal the car would start rolling again due to gravity. It is for THAT reason a totally mechanical parking/emergency brake is installed. Alternately, if the power fails (and there isn’t either a hydraulic or mechanical braking system) then there are only two actions for the electric motors: free wheel or stop the wheels from turning. It is Aptera’s silence on the emergency/parking brake that is a concern.

[len]

You can try info@aptera.us but that may not be monitored full-time

https://in-wheel.com/en/https://in-wheel.com/en/. may have a general answer?

I suppose the Lightyear “0” and the old Lordstown, which use the Elaphe in wheel motors used similar braking(???)

[craig-merrow]

I’m still on a learning curve with Aptera, so bear with me: If I am understanding this correctly, the disc brakes are electric instead of hydraulic? With regenerative braking in use, the calipers would only come into use at low speeds, like coming to a stop?

[Greek]

We are not completely sure how the regenerative braking will work. Most vehicles you can set regenerative braking to completely stop the vehicle. That does not mean it will give you enough braking or emergency braking. If you are a driver that gives the person in front of you enough space so as you can let regenerative braking enough time to slow you down, you may need to use your brakes if they hit their brakes hard.

My bmw i3 will come to a complete stop, if I see a red light in front of me, I try and lift my foot off the accelerator to hopefully stop as close to the intersection pedestrian line as possible(it’s a game that many people play).

My electric motorcycle Zero sr/f will slow down once I let off the throttle but will not come to a complete stop, once it goes down to 5 mph it will continue to roll unabated until gravity takes over.

APTERA being an auto cycle…not sure what their final iteration will reveal….I hope it does come to a complete stop.

[joshua-rosen]

On EVs there are other times that the friction brakes are used then just low speed. Emergency stops for example but also whenever the regen brakes aren’t stopping fast enough. Another situation is if you have a full battery or a cold battery. Regen brakes need a place to dump the energy, if the battery is full then there is no room for additional charge. Batteries also charge and discharge at a slower rate when they are cold. In the winter regen braking won’t work until the battery has warmed up. Hopefully they will have a precondition feature in their app the way Tesla does. In the winter I precondition my M3 before I leave the house, not only does that warm the cabin when the car is plugged in, it also heats the battery. A new feature that Tesla has recently added is including friction braking in one pedal driving, i.e. when you lift your foot the car will slow down or stop even if the regen isn’t working. Hopefully they will copy that feature also.

[raoul-desy]

This leads to an interesting question – what about annual state safety inspections that require checking the brakes? Will owners need to provide information to the inspection station so they can pass inspection and get a sticker?

[ROMAD]

Well, how are the brakes checked? During driving/dynamometer tests or is it just a visual check? If the latter, how are drum brakes checked?

[raoul-desy]

In NY and MA (and I assume most other states) on cars they measure the thickness of the brake pad on one wheel. On motorcycles it is either a visual check or a measurement (I’m not sure), and it may be both wheels. As an autocycle, the inspection would follow be for a motorcycle in NY and MA. Either way, the hub motor will need to be disassembled on one or more wheels to check the pad thickness.

To check pads on drum brakes, I believe you would need to remove the drum. However, disassembling the motor and removing the disc brake caliper to check both pads seems more complex than checking drum brakes.

Either way, the hub motor would need to be disassembles and reassembles once a year. Without more detail than what is shown in the video, I’m just wondering how complex this could be for a quick inspection. In NY the cost of a motorcycle safety inspection is $6, so the inspection stations loose money as it is.

• This reply was modified 1 year, 4 months ago by  Raoul Desy.

[harry-parker]

From the images of the Aptera in-wheel motors I’ve seen, the brake pads are visible once the tire on its rim is removed, when looking from under the vehicle.

[aaron-huffman]

With a quick skim here and around the form, I’m wondering if the Aptera car has parking brakes. I’ve seen many and owned an electric motorcycle. The most undervalued non-factory option for these vehicles is a parking brake. The only way to “park” an electric motorcycle is with something to hold the front brake pressure like the Bullet Brake.

[Biker]

A detailed view of the Alaphe hub motor showed two calipers and one can assume that the second one is for parking brake functionality. Will likely need to wait till closer to production to see the details of that.

[glenn-zajic]

On one of their detailed views I remember seeing a parking brake on the rear wheel. I don’t recall seeing anything on the front wheels yet.

[ROMAD]

I’ve never seen any car with the parking brake on the front wheels; always either the rear or on the drive shaft.